Make: Cummins
Engine: ISL9 CM2350 (2013-17)
Fauld Code: 2646
PID: 110
SPN: 110
FMI: 14
Description: Engine Coolant Temperature – Condition Exists
Troubleshooting:
Reason:
Engine Coolant Temperature – Condition Exists. The EGR valve was closed to reduce engine
coolant temperature.
Effect:
Possible reduced engine performance.
Circuit Description:
The coolant temperature sensor is a variable resistor sensor and is used to measure the
temperature of the coolant of the engine. The engine control module (ECM) supplies 5 volts to
the coolant temperature signal circuit. The ECM monitors the change in voltage caused by
changes in the resistance of the sensor to determine the coolant temperature.
Component Location:
The engine coolant temperature sensor is located on the thermostat housing.
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 engine coolant temperature was above a
threshold and closed the EGR valve to reduce the engine coolant temperature.
Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic
runs and fails.
2) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
3) 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, perform a key cycle, and leave the key in the ON position for 1 minute.
2) The fault code status displayed by INSITE™ electronic service 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) 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:
When the engine coolant temperature nears the engine protection limits, the EGR valve will be
closed to reduce the coolant temperature. This fault code is used as an information fault code,
only indicating that the EGR valve has closed. No malfunction has occurred to cause this fault
code. Other engine protection fault codes will be active if the engine coolant temperature has
exceeded the engine protection limits.
Possible Causes:
1) Inactive fault codes
2) Faulty ECM
Make: Cummins
Engine: ISL9 CM2350 (2013-17)
Fauld Code: 2764
PID: 131
SPN: 1209
FMI: 16
Description: Exhaust Gas Pressure – Data Valid but Above Normal Operating Range –
Moderately Severe Level
Troubleshooting:
Reason:
Exhaust Gas Pressure – Data Valid but Above Normal Operating Range – Moderately Severe
Level. High exhaust gas pressure has been detected by the exhaust gas pressure sensor.
Effect:
Possible reduced engine performance
Circuit Description:
The exhaust gas pressure sensor is used to measure exhaust gas pressure in the exhaust
manifold. This information is used by the engine control module (ECM) to control emissions
and exhaust gas recirculation (EGR) valve operation. The ECM provides a 5 volt supply to the
exhaust gas pressure sensor on the sensor supply circuit. The ECM also provides a ground on
the sensor return circuit. The exhaust gas pressure sensor provides a signal to the ECM on the
exhaust gas pressure sensor signal circuit. This sensor signal voltage changes, based on the
pressure in the exhaust manifold.
Component Location:
The exhaust gas pressure sensor is located above the front section of the exhaust manifold
and is plumbed into the exhaust manifold.
Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is running.
Conditions for Setting the Fault Codes:
Exhaust gas pressure sensor reading was greater that the engine protection limits
Action Taken When the Fault Code is Active:
An engine derate will be activated to bring exhaust gas pressure below the maximum operating
limits.
Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service 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) 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:
N/A
Possible Causes:
1) A malfunctioning variable geometry turbocharger
2) A damaged in-range exhaust gas pressure sensor
3) A plugged or restricted aftertreatment diesel particulate filter
4) A plugged or restricted EGR cooler
Make: Cummins
Engine: ISL9 CM2350 (2013-17)
Fauld Code: 2878
PID: SID 381
SPN: 4097
FMI: 7
Description: Aftertreatment Fuel Drain Valve – Mechanical System Not Responding or Out of
Adjustment
Troubleshooting:
Reason:
Aftertreatment Fuel Drain Valve – Mechanical System Not Responding Properly or Out of
Adjustment. The aftertreatment fuel shutoff drain valve has been detected to be stuck closed.
Effect:
Active aftertreatment diesel particulate filter regeneration will be disabled.
Circuit Description:
The aftertreatment fuel drain valve is used to relieve the fuel pressure in the aftertreatment fuel
injector supply line. Before active regeneration of the aftertreatment DPF, a diagnostic test on
the system is performed. The aftertreatment fuel injector opens and relieves fuel pressure in
the line. The aftertreatment fuel pressure sensor must be reading atmospheric pressure at this
point in the test. The aftertreatment fuel drain valve closes. The aftertreatment fuel shutoff
valve and aftertreatment fuel injector then close and trap the fuel between the aftertreatment
fuel shutoff valve and the aftertreatment fuel injector. The diagnostic checks to make sure the
system maintains fuel pressure.
Component Location:
The aftertreatment fuel drain valve is located in the aftertreatment fuel shutoff manifold.
Conditions for Running the Diagnostics:
This diagnostic runs during active regeneration of the aftertreatment diesel particulate filter.
Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected a stuck closed aftertreatment fuel drain valve
when the aftertreatment fuel pressure does not change after the aftertreatment fuel drain valve
is commanded open.
Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic
runs and fails.
2) Active regeneration of the aftertreatment diesel particulate filter will be disabled unitl the next
key cycle.
3) 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 the INSITE™ electronic service tool Aftertreatment Diesel
Particulate Filter Regeneration Test. Once the temperatures in the aftertreatment are warm
enough to inject diesel fuel into the exhaust, the diagnostic will run.
1) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE
immediately after the diagnostic runs and passes.
2) 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.
Shop Talk:
N/A
Possible Causes:
1) A stuck closed aftertreatment fuel drain valve
2) A plugged or restricted fuel drain line