Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 3316
PID: N/A
SPN: 3242
FMI: 4

Description: Aftertreatment Diesel Particulate Filter Intake Temperature Sensor Circuit- Voltage
Below Normal or Shorted to Low Source
Troubleshooting:
Circuit Description
The aftertreatment diesel particulate filter temperature sensor module is a smart device that
communicates with the engine control module via the J1939 data link. The aftertreatment
diesel partculate filter temperature sensor module performs its own internal diagnostics and
reports malfunctions back to the engine control module using the J1939 data link. The
aftertreatment diesel particulate filter temperature sensor module is used to measure the
aftertreatment diesel oxidation catalyst intake temperature, aftertreatment diesel particulate
filter intake temperature, and aftertreatment diesel particulate filter outlet temperature. The
temperature probes are permanently attached to the aftertreatment diesel particulate filter
temperature sensor module and can not be replaced individually.
Component Location
The aftertreatment diesel particulate filter intake temperature sensor is located in the
aftertreatment system. It is located at the outlet of the diesel oxidation catalyst and before the
diesel particulate filter. Refer to the original equipment manufacturer (OEM) service manual.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position and the engine is
running.
Conditions for Setting the Fault Codes
The aftertreatment diesel particulate filter temperature sensor module reported the
aftertreatment particulate filter intake temperature signal was out of range low.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp
(MIL) immediately when the diagnostic runs and fails.
A default value for the aftertreatment diesel particulate filter intake temperature reading is used.
Active and stationary regeneration of the diesel particulate filter will be disabled.
Diesel exhaust fluid injection into the aftertreatment system is disabled.
Engine torque will be reduced if the engine is operated for an extended period of time with this
fault active.
Conditions for Clearing the Fault Code
To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs
and passes.
For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator
Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active
and inactive faults, as well as extinguish the MIL for OBD applications.
Shop Talk
Possible causes of this fault include:
A malfunctioning aftertreatment diesel particulate filter intake temperature sensor
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring
supplied by the OEM.
For intermittent power supply and datalink communication issues with Aftertreatment
Components, it is highly recommended that the OEM Power Distribution Center fuses and
relays be thoroughly checked for loose, missing or intermittent connections
Possible Cause:
1) Aftertreatment DPF temperature sensor module failure
2) ECM calibration

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 3375
PID: SID 115
SPN: 5397
FMI: 31

Description: Aftertreatment Diesel Particulate Filter Regeneration Too Frequent- Condition
Exists
Troubleshooting:
Circuit Description
The ECM records the time from the completion of an active regeneration of the aftertreatment
diesel particulate filter until the ECM request another active regeneration of the diesel
particulate filter.
Component Location
The aftertreatment diesel particulate filter is located in the exhaust system and is installed by
the original equipment manufacturer (OEM). Refer to the OEM service manual.
Conditions for Running the Diagnostics
This diagnostic only runs after successful completion of an active regeneration of the
aftertreatment diesel particulate filter.
Conditions for Setting the Fault Codes
The time between the completion of a successful active regeneration and the requests for
another active regeneration was less than a threshold.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp
(MIL) immediately when the diagnostic runs and fails.
Conditions for Clearing the Fault Code
This diagnostic can not be run in the shop enviornment.
To validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop
and go city type driving and steady state highway type driving. It may be necessary to load the
unit for certain diagnostics in the ECM to run.
To validate the repair using a Chassis Dynamometer, utilize a routine that incorporates
acceleration and motoring events, steady state highway type operation, and load. This will
simulate normal driving and allow the diagnostics in the ECM to run.
It is necessary to use the “Reset All Faults” command in INSITE™ electronic service tool to
clear this fault and extinguish the amber CHECK ENGINE lamp and/or Malfunction Indicator
Lamp (MIL).
Shop Talk
Possible causes of this fault code include:
A malfunctioning aftertreatment fuel injector
A face plugged aftertreatment diesel oxidation catalyst
A malfunctioning aftertreatment diesel particulate filter differential pressure sensor
An engine malfunction resulting in high engine out soot.
Possible Cause:
1) Aftertreatment DPF differential pressure Sensor failure
2) Fuel rail pressure relief valve failure
3) Loose injector High-Pressure Connector
4) Aftertreatment DPF failure
5) ECM calibration

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 6788
PID: N/A
SPN: 3251
FMI: 2/20

Description: Aftertreatment 1 Diesel Particulate Filter Differential Pressure Sensor – Data Not
Rational – Drifted High
Troubleshooting:
Lamp:
None
Reason:
An offset in the diesel particulate filter differential pressure sensor reading has been detected.
Effect:
Possible reduced engine performance.
Circuit Description:
The Engine Control Module (ECM) provides a 5 volt supply to the aftertreatment diesel
particulate filter differential pressure sensor on the sensor supply circuit. The ECM also
provides a ground on the sensor return circuit. The aftertreatment diesel particulate filter
differential pressure sensor provides a signal to the ECM on the aftertreatment diesel
particulate filter differential pressure sensor signal circuit. This sensor signal voltage changes,
based on the differential pressure across the aftertreatment diesel particulate filter.
Component Location:
The aftertreatment diesel particulate filter differential pressure sensor is mounted on the diesel
particulate filter. It is a combination sensor that detects both diesel particulate filter differential
pressure and outlet pressure.
Conditions for Running the Diagnostics:
This diagnostic consists of two parts:
1. One part runs when the keyswitch is initially turned ON before the engine is started.
2. The second part runs continuously while the engine is running.
Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the aftertreatment diesel particulate filter
differential pressure was greater than 1.5 kpa [0.44 in HG] at initial key ON, or is not changing
with engine conditions.
Action Taken When the Fault Code is Active:
1. The ECM illuminates the amber check engine lamp and/or Malfunction Indicator Lamp (MIL)
after the diagnostic fails on two consecutive trips.
2. A default value of the aftertreatment diesel particulate filter differential pressure is used.
3. Diesel exhaust fluid injection into the aftertreatment system is disabled.
4. Active and stationary regeneration of the diesel particulate filter will be disabled.

5. Exhaust gas recirculation (EGR) valve operation will be disabled.
6. Engine torque will be reduced if the engine is operated for an extended period of time with
this fault active.
Conditions for Clearing the Fault Code:
1. To validate the repair using a diagnostic road test, utilize a route that incorporates both stop
and go city type driving and steady state highway type driving. It may be necessary to load the
unit for certain diagnostics in the ECM to run.
2. To validate the repair using a chassis dynamometer, utilize a routine that incorporates
acceleration and motoring events, steady state highway type operation, and load. This will
simulate normal driving and allow the diagnostics in the ECM to run.
3. Turn the key switch OFF and allow the ECM to completely powerdown.
4. To validate the repair, perform a key cycle and leave the key in the ON position for 2
minutes. Then start the engine and let it idle for 1 minute.
5. The fault code status displayed by the diagnostic tool will change to inactive immediately
after the diagnostic runs and passes.
6. The ECM will turn off the amber check engine lamp immediately after the diagnostic runs
and passes.
7. For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator
Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
8. The reset all faults command in the diagnostic tool can be used to clear active and inactive
faults, as well as extinguish the MIL for OBD applications.
Shop Talk:
Possible causes of this fault code include:
1. Stuck in-range aftertreatment diesel particulate filter differential pressure sensor reading.
2. High resistance in the aftertreatment diesel particulate filter differential pressure sensor
signal or return wires.
3. Disconnected or damaged aftertreatment diesel particulate filter differential pressure sensor
tubes.
4. Plugged aftertreatment differential pressure sensor ports could cause this fault code if
pressure is held in the port after the engine is turned off.
5. Frozen, plugged, or restricted aftertreatment DPF differential pressure sensor tubes.

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 6925
PID: N/A
SPN: 3216
FMI: 11/31

Description: Aftertreatment 1 SCR Intake NOx Sensor – Condition Exists
Troubleshooting:
Lamp:
Amber
Reason:
An incorrect NOx sensor reading has been detected by the aftertreatment intake NOx sensor.
Effect:
Possible reduced engine performance.
Circuit Description:
The aftertreatment intake NOx (Nitrogen Oxides) sensor is a smart device and communicates
with the Engine Control Module (ECM) via the J1939 data link. The aftertreatment intake NOx
sensor performs internal diagnostics and reports malfunctions back to the primary ECM using
the J1939 data link. The NOx sensor is permanently attached to the NOx control module. They
are serviced as a single component and can not be replaced individually. The aftertreatment
intake NOx sensor is used to measure the NOx emissions at the intake of the aftertreatment
system.
Component Location:
The aftertreatment intake NOx sensor is mounted on the engine near the turbocharger turbine
outlet.
Conditions for Running the Diagnostics:
1. This diagnostic runs when the aftertreatment diesel oxidation catalyst intake temperature
sensor has been above 150°C [302°F] for 5 minutes while the engine is running.
2. This diagnostic has to meet specific engine and aftertreatment conditions to run and
complete.
Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the aftertreatment intake NOx reading was higher
or lower than the calculated aftertreatment intake NOx value for the engine operating
conditions.
Action Taken When the Fault Code is Active:
The ECM illuminates the amber check engine lamp and/or Malfunction Indicator Lamp (MIL)
after the diagnostic fails on two consecutive trips.
Conditions for Clearing the Fault Code:
1. To validate the repair, it may be necessary to operate the vehicle on a chassis dynamometer
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Diagnostic Trouble Code Solutions 12/12/2024 23:54:39
or to drive the vehicle in order to get the engine load high enough for the diagnostic to run.
2. The fault code status displayed by the diagnostic tool will change to inactive immediately
after the diagnostic runs and passes.
3. The ECM will turn off the amber check engine lamp immediately after the diagnostic runs
and passes.
4. For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator
Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5. The reset all faults command in the diagnostic tool can be used to clear active and inactive
faults, as well as extinguish the MIL for OBD applications.
Shop Talk:
Possible causes of this fault code include:
1. EGR system leaks.
2. Exhaust system leaks.
3. An incorrectly installed aftertreatment intake NOx sensor.
4. An aftertreatment intake NOx sensor that has carbon buildup on the tip of the sensor.
5. A malfunctioning EGR differential pressure sensor.
6. A malfunctioning EGR valve.
7. Excessive oil consumption.
8. Possible engine misfire.
9. The NOx sensor part number is incorrect.

Make: Cummins
Engine: ISX12 CM2350 (2013-17)

Fauld Code: 2754
PID: 81
SPN: 81
FMI: 16

Description: Engine Diesel Particulate Filter Intake Pressure- Data Valid But Above Normal
Operating range- Moderately Severe Level
Troubleshooting:
Circuit Description
The engine aftertreatment system monitors the soot load in the aftertreatment diesel particulate
filter. Under normal operating conditions, the aftertreatment diesel particulate filter is selfcleaning,
where soot is converted to carbon dioxide, nitrogen, and water. Under light load
operating conditions, it can be necessary to perform a stationary regeneration of the
aftertreatment diesel particulate filter. The soot load in the aftertreatment diesel particulate filter
is estimated, using the aftertreatment differential pressure sensor and the calculated soot
output of the engine.
Component Location
The aftertreatment diesel particulate filter is located in the exhaust system and is installed by
the original equipment manufacturer (OEM). Refer to the OEM service manual.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is running.
Conditions for Setting the Fault Codes
Soot accumulation within the diesel particulate filter occurred at a higher rate than under
normal operating conditions.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs
and fails.
Conditions for Clearing the Fault Code
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
Shop Talk
Possible causes of this fault code include:
Boost leaks in the charge-air cooler plumbing
A malfunction of the variable geometry turbocharger (VGT)
A malfunction of the exhaust gas recirculation (EGR) valve
A malfunctioning in-range EGR differential pressure sensor
A malfunctioning in-range boost pressure sensor
A malfunctioning in-range barometric pressure sensor
A cylinder misfire or overfueling.
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring
supplied by the OEM.
For intermittent power supply and datalink communication issues with Aftertreatment
Components, it is highly recommended that the OEM Power Distribution Center fuses and
relays be thoroughly checked for loose, missing or intermittent connections.
Possible Cause:
1) Charge-air cooler failure
2) Barometric pressure sensor failure
3) Intake manifold pressure sensor failure
4) Exhaust manifold pressure sensor failure
5) Aftertreatment DPF differential pressure sensor failure
6) Fuel rail pressure relief valve failure
7) Loose injector high-pressure connector(s)
8) High-pressure connector failure
9) ECM calibration

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 3135
PID: N/A
SPN: 3610
FMI: 2

Description: Aftertreatment 1 Diesel Particulate Filter Outlet Pressure- Data Erratic,
Intermittent, or Incorrect
Troubleshooting:
Circuit Description
The engine control module (ECM) provides a 5 volt supply to the aftertreatment diesel
particulate filter outlet pressure sensor on the sensor supply circuit. The ECM also provides a
ground on the sensor return circuit. The aftertreatment diesel particulate filter outlet pressure
sensor provides a signal to the ECM on the aftertreatment diesel particulate filter outlet
pressure sensor signal circuit. This sensor signal voltage changes based on the pressure at
the outlet of the aftertreatment diesel particulate filter.
Component Location
The aftertreatment diesel particulate filter differential pressure sensor is mounted on the diesel
particulate filter. It is a combination sensor that detects both diesel particulate filter differential
pressure and outlet pressure. Refer to the original equipment manufacturer (OEM) service
manual.
Conditions for Running the Diagnostics
This diagnostic consists of two parts:
One part runs when the keyswitch is initially turned ON before the engine is started
The second part runs continuously while the engine is running.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the aftertreatment diesel particulate filter outlet
pressure was greater than 1.5 kpa [0.22 psi] or less than -1.5 kpa [0.22 psi] at initial key ON, or
was not changing with engine conditions.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp
(MIL) after the diagnostic fails on two consecutive trips.
Diesel exhaust fluid injection into the aftertreatment system is disabled.
Engine torque will be reduced if the engine is operated for an extended period of time with this
fault active.
Conditions for Clearing the Fault Code
To validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop
and go city type driving and steady state highway type driving. It may be necessary to load the
unit for certain diagnostics in the ECM to run.
To validate the repair using a Chassis Dynamometer, utilize a routine that incorporates
acceleration and motoring events, steady state highway type operation, and load. This will
simulate normal driving and allow the diagnostics in the ECM to run.
Turn the key switch OFF and allow the ECM to completely powerdown.
To validate the repair, perform a key cycle and leave the key in the ON position for 2 minutes.
Then start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs
and passes.
For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator
Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active
and inactive faults, as well as extinguish the MIL for OBD applications.
Shop Talk
Possible causes of this fault code include:
Stuck in-range aftertreatment diesel particulate filter outlet pressure sensor reading
High resistance in the aftertreatment diesel particulate filter outlet pressure sensor signal or
return wires
Higher than expected diesel particulate filter outlet pressure
Excessive diesel exhaust fluid (DEF) deposits in the aftertreatment decomposition tube
Plugged aftertreatment outlet pressure sensor ports could cause this fault code if pressure is
held in the port after the engine is turned OFF.
Frozen, plugged, or restricted aftertreatment DPF differential pressure sensor tubes.
Note: It is possible to set this fault in a shop environment by performing a key cycle with the
tailpipe connected to an exhaust ventilation system.
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring
supplied by the OEM.
Possible Cause:
1) Aftertreatment DPF differential pressure sensor failure
2) OEM harness
3) ECM failure

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 3314
PID: N/A
SPN: 4765
FMI: 3

Description: Aftertreatment Diesel Oxidation Catalyst Intake Temperature Sensor Circuit-
Voltage Above Normal or Shorted to High Source
Troubleshooting:
Circuit Description
The aftertreatment diesel particulate filter temperature sensor module is a smart device that
communicates with the engine control module via the J1939 data link. The aftertreatment
diesel partculate filter temperature sensor module performs its own internal diagnostics and
reports malfunctions back to the engine control module using the J1939 data link. The
aftertreatment diesel particulate filter temperature sensor module is used to measure the
aftertreatment diesel oxidation catalyst intake temperature, aftertreatment diesel particulate
filter intake temperature, and aftertreatment diesel particulate filter outlet temperature. The
temperature probes are permanently attached to the aftertreatment diesel particulate filter
temperature sensor module and can not be replaced individually.
Component Location
The aftertreatment diesel oxidation catalyst intake temperature sensor is located in the
aftertreatment system. It is located at the intake of the aftertreatment catalyst. Refer to the
OEM service manual.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position and the engine is
running.
Conditions for Setting the Fault Codes
The aftertreatment diesel particulate filter temperature sensor module reported the
aftertreatment diesel oxidation catalyst intake temperature signal was out of range high.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp
(MIL) immediately when the diagnostic runs and fails.
A default value for the aftertreatment diesel oxidation catalyst intake temperature sensor
reading is used.
Diesel exhaust fluid injection into the aftertreatment system is disabled.
Active and stationary regeneration of the diesel particulate filter will be disabled.
Exhaust Gas Recirculation (EGR) valve operation will be disabled.
Engine torque will be reduced if the engine is operated for an extended period of time with this
fault active.
Conditions for Clearing the Fault Code
To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs
and passes.
For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator
Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active
and inactive faults, as well as extinguish the MIL for OBD applications.
Shop Talk
Possible causes of this fault include:
A malfunctioning aftertreatment diesel oxidation catalyst intake temperature sensor
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring
supplied by the OEM.
For intermittent power supply and datalink communication issues with Aftertreatment
Components, it is highly recommended that the OEM Power Distribution Center fuses and
relays be thoroughly checked for loose, missing or intermittent connections.
Possible Cause:
1) Aftertreatment DPF temperature sensor module failure
2) ECM calibration

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 3315
PID: N/A
SPN: 4765
FMI: 2

Description: Aftertreatment 1 Diesel Oxidation Catalyst Intake Temperature- Data Erratic,
Intermittent, or Incorrect
Troubleshooting:
Circuit Description
The aftertreatment diesel particulate filter temperature sensor module is a smart device that
communicates with the engine control module via the J1939 data link. The aftertreatment
diesel partculate filter temperature sensor module performs its own internal diagnostics and
reports malfunctions back to the engine control module using the J1939 data link. The
aftertreatment diesel particulate filter temperature sensor module is used to measure the
aftertreatment diesel oxidation catalyst intake temperature, aftertreatment diesel particulate
filter intake temperature, and aftertreatment diesel particulate filter outlet temperature. The
temperature probes are permanently attached to the aftertreatment diesel particulate filter
temperature sensor module and can not be replaced individually.
Component Location
The aftertreatment diesel oxidation catalyst intake temperature sensor is located in the
aftertreatment system. It is located at the intake of the aftertreatment catalyst. Refer to the
OEM service manual.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position and the engine is
running.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the difference between the aftertreatment diesel
oxidation catalyst intake temperature sensor data and diesel particulate filter intake
temperature sensor data did not match the expected value for the present engine operating
conditions.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp
(MIL) after the diagnostic fails on two consecutive trips.
A default value for the aftertreatment diesel oxidation catalyst intake temperature sensor
reading is used.
Diesel exhaust fluid injection into the aftertreatment system is disabled.
Engine torque will be reduced if the engine is operated for an extended period of time with this
fault active.
Conditions for Clearing the Fault Code
To validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop
and go city type driving and steady state highway type driving. It may be necessary to load the
unit for certain diagnostics in the ECM to run.
To validate the repair using a Chassis Dynamometer, utilize a routine that incorporates
acceleration and motoring events, steady state highway type operation, and load. This will
simulate normal driving and allow the diagnostics in the ECM to run.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs
and passes.
For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator
Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active
and inactive faults, as well as extinguish the MIL for OBD applications.
Shop Talk
Possible causes of this fault code include:
A malfunctioning aftertreatment diesel particulate filter intake temperature sensor
A malfunctioning aftertreatment diesel oxidation catalyst intake temperature sensor
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring
supplied by the OEM.
For intermittent power supply and datalink communication issues with Aftertreatment
Components, it is highly recommended that the OEM Power Distribution Center fuses and
relays be thoroughly checked for loose, missing or intermittent connections.
Possible Cause:
1) Aftertreatment DPF temperature sensor failure
2) ECM calibration

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 1921
PID: SID 324
SPN: 3251
FMI: 16

Description: Aftertreatment Diesel Particulate Filter Differential Pressure- Data Valid But Above
Normal Operating Range- Moderately Severe Level
Troubleshooting:
Circuit Description
The engine aftertreatment system monitors the soot load in the aftertreatment diesel particulate
filter. Under normal operating conditions, the aftertreatment diesel particulate filter is selfcleaning,
where soot is converted to carbon dioxide, nitrogen, and water. Under light load
operating conditions, it can be necessary to perform a stationary regeneration of the
aftertreatment diesel particulate filter. The soot load in the aftertreatment diesel particulate filter
is estimated, using the aftertreatment differential pressure sensor and the calculated soot
output of the engine.
Component Location
The aftertreatment diesel particulate filter is located in the exhaust system and is installed by
the original equipment manufacturer (OEM). Refer to the OEM service manual.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is running.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the soot load of the aftertreatment diesel
particulate filter was moderately severe. The aftertreatment system needs to be regenerated to
remove the soot.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs
and fails.
The ECM will flash the aftertreatment lamp immediately after the diagnostic fails.
Torque output of the engine will be reduced as the soot load in the aftertreatment diesel
particulate filter increases.
Mobile regeneration of the diesel particulate filter will be disabled.
Exhaust Gas Recirculation (EGR) valve operation will be disabled.
Conditions for Clearing the Fault Code
After completing a stationary regeneration (as instructed in this fault code troubleshooting tree)
and no additional faults become active, the repair has been validated.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs
and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active
and inactive faults, as well as extinguish the MIL for OBD applications.
Shop Talk
Note: This fault code indicates that the aftertreatment diesel particulate filter requires
maintenance by performing a stationary regeneration procedure. This is a maintenance
procedure only and is not covered by Cummins® warranty.
Note: Repeated occurrences of this fault code may indicate the engine requires frequent
regeneration. Refer to symptom tree t147 (Aftertreatment Diesel Particulate Filter-Excessive
Automatic and/or Stationary Regeneration) to identify the cause of frequent regeneration.
Possible causes of this fault code include:
The engine has been operating in a light load condition that prevents exhaust temperatures
from being high enough to actively regenerate the aftertreatment diesel particulate filter.
Possible engine damage that causes excessive black soot to be generated.
If Fault Code 2777 is active along with Fault Code 1921, this indicates that a regeneration
inhibit message has been received by the engine ECM and that active regeneration of the
aftertreatment diesel particulate filter was not permitted. Confirm that OEM settings for the
aftertreatment permit switch are configured correctly. A stationary regeneration of the
aftertreatment diesel particulate filter can be performed. Use INSITE™ electronic service tool.
Possible Cause:
1) Damaged DPF
2) ECM calibration

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 1922
PID: SID 324
SPN: 3251
FMI: 0

Description: Aftertreatment Diesel Particulate Filter Differential Pressure- Data Valid But Above
Normal Operating Range- Most Severe Level
Troubleshooting:
Circuit Description
The engine aftertreatment system monitors the soot load in the aftertreatment diesel particulate
filter. Under normal operating conditions, the aftertreatment diesel particulate filter is selfcleaning,
where soot is converted to carbon dioxide, nitrogen, and water. Under light load
operating conditions, it can be necessary to perform a stationary regeneration of the
aftertreatment diesel particulate filter. The soot load in the aftertreatment diesel particulate filter
is estimated, using the aftertreatment differential pressure sensor and the calculated soot
output of the engine.
Component Location
The aftertreatment diesel particulate filter is located in the exhaust system and is installed by
the original equipment manufacturer (OEM). Refer to the OEM service manual.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is running.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the soot load of the aftertreatment diesel
particulate filter had exceeded the maximum operating limits.
Action Taken When the Fault Code is Active
The ECM illuminates the red STOP ENGINE lamp immediately after the diagnostic runs and
fails.
Torque output of the engine will be reduced as the soot load in the aftertreatment diesel
particulate filter increases.
Active and stationary regeneration of the diesel particulate filter will be disabled.
Exhaust Gas Recirculation (EGR) valve operation will be disabled.
Conditions for Clearing the Fault Code
Use INSITE™ electronic service tool to perform the Diesel Particulate Filter Reset procedure
found under the Aftertreatment Maintenance section of Advanced ECM Data.
After completing a stationary regeneration (as instructed in this fault code troubleshooting tree)
and no additional faults become active, the repair has been validated.
The ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and
passes.
Shop Talk
Note: Repeated occurrences of this fault code may indicate the engine requires frequent
regeneration. Refer to symptom tree t147 (Aftertreatment Diesel Particulate Filter-Excessive
Automatic and/or Stationary Regeneration) to identify the cause of frequent regeneration.
Possible causes of this fault code include:
The aftertreatment wiring harness or the aftertreatment temperature sensor connector pin
installation may be incorrect.
The engine has been operating in a light load condition that prevents exhaust temperatures
from being high enough to actively regenerate the aftertreatment diesel particulate filter.
A possible base engine malfunction that causes excessive black soot to be generated.
If both Fault Code 1921 and 2777 are inactive with an active Fault Code 1922, this indicates
that a regeneration inhibit message has been received by the engine ECM and that active
regeneration of the aftertreatment diesel particulate filter was not allowed. Use the OEM
manuals to confirm that the OEM settings for the aftertreatment permit switch are configured
correctly.
Possible Cause:
1) Aftertreatment DPF differential pressure sensor failure
2) DPF failure
3) ECM calibration

Make: Cummins
Engine: ISX CM871 (2007-09)

Fauld Code: 1981 (CPL 3774 y 3775)
PID: SID 324
SPN: 3251
FMI: 0

Description: Aftertreatment Particulate Filter Differential Pressure – Data Valid But Above
Normal Operating Range – Least Severe Level. The aftertreatment differential pressure has
exceeded the maximum operating limits or the diesel particulate filter is plugged.
Troubleshooting:
Verify the electronic control module (ECM) calibration is correct. Check the calibration revision
history found on QuickServe™ Online for applicable changes to the calibration stored in the
ECM. If necessary, calibrate the ECM.
An engine torque derate for extended EGR valve closed operation exists for this fault code.
The engine torque derate for extended EGR valve closed operation operates on a time based
system. The time based system will count up anytime a fault code that closes the EGR valve is
active. Once the timer reaches 20 hours, an engine torque derate of approximately 15 percent
will be applied.
The engine torque derate will be removed as soon as the fault code goes inactive, and the
timer will begin to count down. If the fault code reoccurs within the next 20 hours of engine
operation, the engine torque derate will immediately be applied, and the timer will then reset to
20 hours. The engine must operate for 20 hours with no active faults that close the EGR valve
for the timer to clear. After the timer has cleared, the engine must then operate for another 20
hours with an active fault code that closes the EGR valve to apply the derate.
This fault code indicates that the soot load inside the aftertreatment diesel particulate filter has
reached the maximum level. Regeneration of the aftertreatment diesel particulate filter at this
stage is not possible. The aftertreatment diesel particulate filter must be inspected. If it meets
the inspection criteria, it can be cleaned using an SPX air pulse cleaning machine (or
equivalent machine). If it does not meet the inspection criteria, it must be replaced.
Possible causes:
1)The aftertreatment diesel particulate filter can be plugged with soot.
2)The engine has been operating in light load conditions that prevent exhaust temperatures
from being high enough to actively regenerate the aftertreatment particulate filter.
3)The aftertreatment wiring harness connectors could be connected to the wrong
aftertreatment exhaust gas temperature sensor.
4)The aftertreatment wiring harness or aftertreatment exhaust gas temperature sensor
connector pin installation could be incorrect.
5)The aftertreatment diesel particulate filter differential pressure sensor has malfunctioned.
6)An engine malfunction that is elevating the engine smoke output.
7)The aftertreatment diesel particulate filter can accumulate an excessive amount of ash in a
short time period. This can be due to excessive oil consumption or due to non-combustible
elements such as, but not limited to, iron, potassium, or calcium contained in fuel additives.
Possible repairs:
1)Replace the aftertreatment diesel particulate filter differential pressure sensor.
2)Install the aftertreatment wiring harness connectors in the correct locations.
3)Install the pins in the correct connector locations.
4)Install the turbocharger actuator.
5)Replace the DPF.
6)Replace the ECM.
Page

Make: Cummins
Engine: ISX CM871 (2007-09)

Fauld Code: 1981 (NON CPL 3774 y 3775)
PID: SID 324
SPN: 3251
FMI: 0

Description: Aftertreatment Particulate Filter Differential Pressure – Data Valid But Above
Normal Operating Range – Least Severe Level. The aftertreatment differential pressure has
exceeded the maximum operating limits or the diesel particulate filter is plugged.
Troubleshooting:
Verify the ECM calibration is correct. Check the calibration revision history found on
QuickServe™ Online for applicable changes to the calibration stored in the ECM. If necessary,
calibrate the ECM.
An engine torque derate for extended EGR valve closed operation exists for this fault code.
The engine torque derate for extended EGR valve closed operation operates on a time based
system. The time based system will count up anytime a fault code that closes the EGR valve is
active. Once the timer reaches 20 hours, an engine torque derate of approximately 15 percent
will be applied.
The engine torque derate will be removed as soon as the fault code goes inactive, and the
timer will begin to count down. If the fault code reoccurs within the next 20 hours of engine
operation, the engine torque derate will immediately be applied, and the timer will then reset to
20 hours. The engine must operate for 20 hours with no active faults that close the EGR valve
for the timer to clear. After the timer has cleared, the engine must then operate for another 20
hours with an active fault code that closes the EGR valve to apply the derate.
This fault code indicates that the soot load inside the aftertreatment diesel particulate filter has
reached the maximum level. Regeneration of the aftertreatment diesel particulate filter at this
stage is not possible. The aftertreatment diesel particulate filter must be inspected. If it meets
the inspection criteria, it can be cleaned using an SPX air pulse cleaning machine, or
equivalent machine. If it does not meet the inspection criteria, it must be replaced.
Possible causes:
1)The aftertreatment diesel particulate filter can be plugged with soot.
2)The engine has been operating in light load conditions that prevent exhaust temperatures
from being high enough to actively regenerate the aftertreatment particulate filter.
3)The aftertreatment wiring harness connectors could be connected to the wrong
aftertreatment exhaust gas temperature sensor.
4)The aftertreatment wiring harness or aftertreatment exhaust gas temperature sensor
connector pin installation could be incorrect.
5)The aftertreatment diesel particulate filter differential pressure sensor has malfunctioned.
6)An engine malfunction that is elevating the engine smoke output.
7)The aftertreatment diesel particulate filter can accumulate an excessive amount of ash in a
short time period. This can be due to excessive oil consumption or due to non-combustible
elements such as, but not limited to, iron, potassium, or calcium contained in fuel additives.
Possible repairs:
1)Replace the aftertreatment diesel particulate filter differential pressure sensor.
2)Install the aftertreatment wiring harness connectors in the correct locations.
3)Install the pins in the correct connector locations.
4)Install the turbocharger actuator.
5)Replace the DPF.
6)Replace the ECM.

Make: Cummins
Engine: ISX12 CM2250 (2010-12)

Fauld Code: 352
PID: SID 212
SPN: 3509
FMI: 4

Description: Sensor Supply 1 Circuit- Voltage Below Normal or Shorted to Low Source
Troubleshooting:
Circuit Description
The sensor supply 1 of the electronic control module (ECM) provides a 5 volt supply for the
Exhaust Gas Recirculation (EGR) differential pressure sensor, exhaust gas pressure sensor,
EGR valve position sensor, and EGR orifice pressure sensor (if equipped).
Component Location
Sensor supply 1 is located in the ECM and provides a 5 volt supply to various engine sensors.
The supply voltage is spliced off in the engine harness to each sensor it supports.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine
is operating.
Conditions for Setting the Fault Codes
The ECM detects that the sensor supply 1 signal voltage is less than 4.75-VDC for more than
one second.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE light and/or the Malfunction Indicator Lamp
(MIL) immediately when the diagnostic runs and fails.
A default value is used for all of the sensors on the sensor supply 1 circuit.
Conditions for Clearing the Fault Code
To validate the repair, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.
For On Board Diagnostic (OBD) engines, the ECM will turn off the MIL after three consecutive
trips where the diagnostic runs and passes.
The “Reset All Faults” command in INSITE™ electronic service tool can be used to clear active
and inactive faults, as well as extinguish the MIL for OBD applications.
Shop Talk
Low voltage on the +5 volt supply wire can be caused by a short circuit to ground in a supply
wire, a short circuit between a supply wire and a return wire, a malfunctioning sensor, or a
malfunctioning ECM power supply.
Possible Cause:
1) EGR differential pressure sensor failure
2) Exhaust gas pressure sensor failure
3) EGR valve position sensor failure
4) EGR orifice pressure sensor failure
5) Aftertreatment fuel pressure sensor failure
6) Engine harness
7) ECM calibration

Make: Cummins
Engine: ISX12 CM2250 (2010-12)

Fauld Code: 428
PID: 97
SPN: 97
FMI: 3

Description: Water-In-Fuel Indicator Sensor Circuit- Voltage Above Normal or Shorted to High
Source
Troubleshooting:
Circuit Description
The water-in-fuel sensor is attached to the fuel filter. The electronic control module (ECM)
provides a 5 volt reference signal to the water-in-fuel sensor. When the water collected in the
fuel filter covers the sensor probes, the water-in-fuel sensor then pulls the 5-VDC reference
voltage to ground, indicating high water accumulation in the fuel filter.
Component Location
The water-in-fuel sensor is integrated into the bottom of the OEM supplied suction fuel filter.
The OEM supplied fuel filter is located on the intake side of the engine.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position.
Conditions for Setting the Fault Codes
The ECM detects that the water-in-fuel sensor signal voltage is above 4.95-VDC for 1 second.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs
and fails.
Conditions for Clearing the Fault Code
To validate the repair, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active
and inactive faults.
Shop Talk
Possible causes for this fault code include:
Open RETURN or SIGNAL circuit in the harness, connectors, or sensor
SIGNAL wire shorted to sensor supply or battery voltage.
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring
supplied by the OEM.
For intermittent power supply and datalink communication issues with Aftertreatment
Components, it is highly recommended that the OEM Power Distribution Center fuses and
relays be thoroughly checked for loose, missing or intermittent connections.
Possible Cause:
1) Engine Harness
2) ECM calibration

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 429
PID: N/A
SPN: 97
FMI: 4

Description: Water-In-Fuel Indicator Sensor Circuit- Voltage Below Normal or Shorted to Low
Source
Troubleshooting:
Circuit Description
The water-in-fuel sensor is attached to the fuel filter. The engine control module (ECM)
provides a 5 volt reference signal to the water-in-fuel sensor. When the water collected in the
fuel filter covers the sensor probes, the water-in-fuel sensor pulls the 5-VDC reference voltage
to ground, indicating high water accumulation in the fuel filter.
Component Location
The water-in-fuel sensor is integrated into the bottom of the OEM supplied suction fuel filter.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine
is running.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the water in fuel sensor signal voltage was less
than 0.05-VDC for 1 second.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs
and fails.
Conditions for Clearing the Fault Code
To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs
and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active
and inactive faults, as well as extinguish the MIL for OBD applications.
Shop Talk
Possible causes of this fault code include:
Signal circuit shorted to ground in the harness, sensor, or connector.
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring
supplied by the OEM.
Possible Cause:
1) ECM failure
2) Engine harness

Make: Cummins
Engine: ISX CM871 (2007-09)

Fauld Code: 1893
PID: SID 324
SPN: 3251
FMI: 2

Description: EGR Valve Control Circuit – Abnormal Update Rate. No communications or invalid
data transfer rate detected on the SAE J1939 data link between the ECM and the smart EGR
valve.
Troubleshooting:
Verify the electronic control module (ECM) calibration is correct. Check the calibration revision
history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If
necessary, calibrate the ECM. For ISX and ISM engines, see the following procedure in the
corresponding Troubleshooting and Repair Manual for the engine being serviced.
This fault code is logged when the primary engine ECM did not receive valid SAE J1939
information from the EGR valve.
Possible causes of this fault code include:
1)The EGR valve is not receiving power from the ECM. This could be caused by an open
circuit in the power supply wire or low voltage supplied by the primary engine ECM.
2)Open return circuit on the EGR valve circuit between the engine ECM and the EGR valve.
3)Open or short circuit on the SAE J1939 data link circuit between the ECM and the EGR
valve.
4)Intermittent communications between the EGR valve and the primary engine ECM on the
SAE J1939 data link.
5)Malfunctioning termination resistors in the engine data link harness.
6)A malfunctioning engine ECM.
7)A malfunctioning EGR valve.
Possible repairs:
1)Clean the connector and pins.
2)Tighten the ground connection.
3)Replace the engine harness.
4)Replace the ECM.
5)Replace the SAE J1939 termination resistor.
6)Repair or replace the engine harness.
7)Replace the EGR valve.

Make: Cummins
Engine: ISX CM871 (2007-09)

Fauld Code: 1896
PID: SID 146
SPN: 2791
FMI: 13

Description: EGR Valve Controller – Out of Calibration. The EGR valve has failed the automatic
calibration procedure at initial key ON.
Troubleshooting:
Verify the ECM calibration is correct. Check the calibration revision history found on
QuickServe™ Online for applicable fixes to the calibration stored in the ECM. If necessary,
calibrate the ECM.
When the keyswitch is initially turned ON, and at various times during engine operation, the
closed position of the EGR valve is checked. This diagnostic checks to make sure the EGR
valve is not stuck open.
This fault code is logged when the following error conditions exist:
1)The EGR valve motor measures the position of the EGR valve at initial key ON. If the valve is
detected to be out of the normal position, this fault code will be logged.
2)The EGR valve will close when the fault code is active.
3)The fault code will remain active until the next key cycle.
The ECM calibration contains an automatic EGR valve override test 30 seconds after turning
the keyswitch ON. The EGR valve will be commanded open to 60 percent and will be held in
this position for 1 minute and then it will be commanded to 0 percent open. Turn the keyswitch
OFF for 20 seconds and then turn the keyswitch ON and read the fault codes. If Fault Code
1896 is active, this indicates the EGR valve is stuck in the open position.
The fault code will only become inactive if the initial key ON EGR position check passes.
Possible repairs:
1)Replace the EGR valve.

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

FAULD CODE: 125
PID: PID 102
SPN: 102
FMI: 18

Description: Intake Manifold 1 Pressure- Data valid But Below Normal Operating Range-
Moderately Severe Level
Troubleshooting:
Circuit Description
The engine control module (ECM) provides a 5 volt supply to the intake manifold pressure
sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return
circuit. The intake manifold pressure sensor provides a signal to the ECM on the intake
manifold pressure sensor signal circuit. This sensor signal voltage changes based on the
pressure in the intake manifold.
Component Location
The intake manifold 1 pressure/temperature sensor is located in the air intake horn.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is running.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the intake manifold pressure reading was below
the expected level for the engine operating conditions.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp
(MIL) immediately when the diagnostic runs and fails.
Exhaust Gas Recirculation (EGR) valve operation will be disabled.
Engine torque will be reduced if the engine is operated for an extended period of time with this
fault active.
Conditions for Clearing the Fault Code
To validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop
and go city type driving and steady state highway type driving. It may be necessary to load the
unit for certain diagnostics in the ECM to run.
To validate the repair using a Chassis Dynamometer, utilize a routine that incorporates
acceleration and motoring events, steady state highway type operation, and load. This will
simulate normal driving and allow the diagnostics in the ECM to run.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs
and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active
and inactive faults, as well as extinguish the MIL for OBD applications.
Shop Talk
The intake manifold 1 pressure sensor monitors pressure in the intake manifold. This fault is
set active when the intake manifold pressure is too low for the present engine operating
conditions. The ECM commands a charge flow command and the VGT and EGR valve move to
meet this command. If the engine is unable to achieve the desired oxygen level necessary for
complete combustion, this fault code is logged.
Possible causes of this fault are:
Leaks in the air intake system between the turbocharger and intake manifold
A damaged intake manifold pressure sensor
A damaged barometric pressure sensor
Restriction in the charge-air cooler
Leaks or restrictions in the EGR system plumbing
Fuel inlet restriction too high (normally caused by a restricted fuel filter).
Possible Cause:
1) Charge-air cooler failure
2) Intake manifold temperature/pressure sensor failure
3) ECM calibration

Make: Cummins
Engine: ISX12 CM2250 (2010-12)

Fauld Code: 143
PID: 100
SPN: 100
FMI: 18

Description: Engine Oil Rifle Pressure- Data Valid But Below Normal Operating Range-
Moderately Severe Level
Troubleshooting:
Circuit Description
The engine control module (ECM) provides a 5 volt supply to the engine oil pressure sensor on
the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The
engine oil pressure sensor provides a signal to the ECM on the engine oil pressure sensor
signal circuit. This sensor signal voltage changes, based on the pressure in the oil rifle. The
ECM will detect a low signal voltage at operating conditions when the oil pressure may be
slightly lower. The ECM will detect a high signal voltage during high engine speeds or
operating conditions when the oil temperature is low.
If the ECM detects low signal voltage, indicating low engine oil pressure, this fault code sets.
Component Location
The engine oil pressure sensor is located on the left side of the engine block.
Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position and the engine is
operating.
Conditions for Setting the Fault Codes
The ECM detects that the engine oil pressure is less than the engine protection limits for more
than 5 seconds.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs
and fails.
A torque derate issued by the ECM limits the power output of the engine.
Conditions for Clearing the Fault Code
To validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stopand-
go city driving and steady state highwaye driving. It may be necessary to load the unit for
certain diagnostics in the ECM to run.
To validate the repair using a Chassis Dynamometer Test, utilize a routine that incorporates
acceleration and motoring events, steady state highway operation, and load. This will simulate
normal driving and allow the diagnostics in the ECM to run.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
and the torque derate will be removed immediately after the oil pressure reading is detected to
be within the normal operating range and the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.
The “Reset All Faults” command in INSITE™ electronic service tool can be used to clear active
and inactive faults.
Shop Talk
Possible causes of this fault code include:
Low oil pressure
Incorrect oil level
Degraded, diluted, or incorrect engine oil.
Possible Cause:
1) ECM calibration

Make: Cummins
Engine: ISX CM870 (2003-06)

Fauld Code: 197
PID: 111
SPN: 111
FMI: 1

Description: Coolant Level – Data Valid But Below Normal Operating Range – Moderately
Severe Level. Low engine coolant level detected.
Troubleshooting:
This fault code goes active when the coolant level inside the radiator top tank or surge tank
drops below the sensor level. Fill the top tank with coolant.
If this fault code is active and the coolant level is not low, disconnect the coolant level sensor
and check the connectors for traces of coolant. If coolant is found at the electrical connectors,
the sensor has malfunctioned and must be replaced.
For intermittent power supply and datalink communication issues with Aftertreatment
Components, it is highly recommended that the OEM Power Distribution Center fuses and
relays be thoroughly checked for loose, missing or intermittent connections.
Note: It may not be possible to perform an aftertreatment diesel particulate filter (DPF)
regeneration while this fault code is active.
Possible repairs:
1)Add coolant to the engine.
2)If necessary, calibrate the ECM.

Make: Cummins
Engine: X15 CM2450 X124B (2018 & Newer)

Fauld Code: 351
PID: PID 110
SPN: 627
FMI: 12

Description: Injector Power Supply- Bad Intelligent Device or Component
Troubleshooting:
Circuit Description
Between each injection event, the Engine Control Module (ECM) attempts to recharge the
injector power supply. The injector power supply consists of a bank of capacitors; if this power
supply is maintained at high voltage. Recharging is accomplished by recovering energy stored
in the injector solenoids. For the injector power supply to remain fully charged, there must be
good ECM battery power and ground, a good engine speed sensor, and good injector circuits.
Component Location
The engine harness connects the ECM to the pass-through connector(s) that are located in the
rocker housing. Internal injector harnesses are located under the valve cover and connect the
injectors to the engine harness at the pass-through connector(s).
Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine
is running.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the measured injector power supply voltage was
less than the commanded injector power supply voltage.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp
(MIL) immediately when the diagnostic runs and fails.
Exhaust Gas Recirculation (EGR) valve operation will be disabled.
Engine torque will be reduced if the engine is operated for an extended period of time with this
fault active.
Conditions for Clearing the Fault Code
To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs
and passes.
For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator
Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active
and inactive faults, as well as extinguish the MIL for OBD applications.
Shop Talk
This fault code will become active after key ON if the battery charge is above a minimum
threshold, and, at the same time, the measured injector power supply voltage is lower than the
commanded injector power supply voltage.
Possible Cause:
1) ECM failure
2) ECM power supply harness, Fuses, fuses holders
3) Battery Terminals
4) Battery Failure