Make: Cummins
Engine: ISM CM876 (2007-09)
Fauld Code: 2322
PID: SID 64
SPN: 723
FMI: 2
Description: Engine Camshaft Speed/Position Sensor – Data Erratic, Intermittent, or Incorrect.
Camshaft engine speed sensor intermittent synchronization.
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.
During engine operation, the ECM monitors the secondary speed sensor (camshaft speed
sensor) signal. Fault Code 778 will become active and light the yellow lamp if the signal from
the secondary speed sensor is not present or degraded for more than 3 continuous seconds. If
over a period of time the ECM detects several incidents of a loss of the secondary speed
sensor signal, but the signal loss is short in duration, this fault code will become active. Since
the secondary engine speed signal is not used for normal engine operation, a vehicle operator
should not notice any symptoms related to this problem.
This fault code becomes active whenever the ECM detects a persistent loss of the secondary
engine speed sensor signal over a short period of time.
This fault becomes inactive at each key ON or if the ECM does not detect a loss of the
secondary engine speed sensor signal for at least 20 minutes.
Failures that can cause this fault:
1)Intermittent loss of primary speed sensor signal; the most likely cause is an intermittent open
or short circuit that can be experienced with speed sensor connector problems.
2)Sensor air gap that is marginally too small or too large, or target wheel exhibits excessive
runout.
Actions to take if this fault is intermittent:
1)Look for intermittent engine harness connections in the secondary engine speed sensor
circuit.
2)Look for loose connections at the ECM connector where the pins can not be locked into the
socket.
3)Look for places where the engine harness has worn into a nearby component causing an
intermittent short circuit.
4)Look for pin wear at the speed sensor.
5)Inspect the target wheel for damage.
Possible repairs:
1)Repair or replace the engine harness.
2)Replace or shim the sensor if air gap is out of specification. If the target runout is excessive,
replace the target.
3)Replace the engine camshaft speed/position sensor.
Make: Cummins
Engine: ISM CM875 (2003-06)
Fauld Code: 2346
PID: N/A
SPN: 2789
FMI: 0/15
Description: Turbocharger Turbine Intake Temperature – Data Valid But Above Normal
Operating Range – Least Severe Level. Turbocharger turbine intake temperature has exceeded
the engine protection limit.
Troubleshooting:
The most common cause of this fault code is low boost. Low boost can be caused by several
factors: leaking charge air cooler, loose charge air cooler clamps, malfunctioning components,
(including charge air cooler piping or hoses), intake manifold pressure sensor, variable
geometry turbocharger, turbocharger control valve, or turbocharger control shutoff valve.
NOTE: Prior to running INSITE™ electronic service tool EGR valve and EGR
valve/turbocharger operational test, the ECM Calibration software phase could possibly need
to be updated to the latest software phase. The ECM calibration phase software can be
checked in INSITE™ electronic service tool, under ‘Features and Parameters’. Expand the
selection for ‘System ID and Dataplate’ and go to ‘Calibration Information’. If the software
phase is earlier than shown below, recalibrate the ECM using the January 2006 INCAL™ CDROM,
or later. Engines with the software phase listed below or later do not require a
recalibration.
ISX engines with CM870 (engines built after January 2004) require software phase 06050402.
ISX engines with CM870 (engines built before January 2004) require software phase
05050000.
This is a warrantable calibration change.
This fault code can also be caused be a Turbocharger Fuel Control (TFC) derate which can be
viewed in INSITE™ electronic service tool, under the User Fueling State. TFC derates can be
caused by several factors: high exhaust temperatures, high turbocharger compressor inlet
temperatures, and high turbocharger compressor outlet temperatures.
NOTE: The engine must be loaded to trip this fault code and to determine if the problem has
been found and fixed. It is possible to cause the fault code to log when the engine is placed on
a dynamometer. The fault code will trip because of the stationary nature and high temperatures
encountered on the dynamometer.
Possible repair:
1)Use the INCAL™ Calibration DVD-ROM with the proper calibration software phase to
calibrate the ECM.
2)The engine power output was derated to limit the exhaust temperatures. This is normal
operation. No repairs are necessary.
3)Repair air leaks.
4)Replace the turbocharger assembly.
5)Replace the turbocharger control valve.
6)Repair the air supply from the OEM air tanks.
7)Replace the turbocharger control shutoff valve filter.
8)Replace the turbocharger control shutoff valve.
9)Replace the variable geometry turbocharger.
Make: Cummins
Engine: ISM CM876 (2007-09)
Fauld Code: 2357
PID: SID 146
SPN: 2791
FMI: 7
Description: EGR Valve Control Circuit – Mechanical System Not Responding Properly or Out
of Adjustment. The EGR motor has exceeded the duty cycle limit, indicating a stuck open 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, recalibrate the ECM.
This fault code is triggered when the EGR valve motor is unable to move the EGR valve in the
open position. This is normally caused by a restriction in the EGR valve not allowing the EGR
valve to move to the commanded position.
The fault code will be inactive at key-on. It will only go active if the EGR valve is commanded
open and the EGR valve is unable to move to the commanded position.
The ECM calibration contains an automatic EGR valve override test. Thirty seconds after
turning the keyswitch on, the EGR valve all 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 that the EGR valve is stuck in the open position.
The aftertreatment system must be inspected after making the appropriate repair outlined in
this fault code troubleshooting tree. Progressive damage to the aftertreatment system may
have occurred. Perform the Snap Acceleration Test to check for a damaged diesel particulate
filter.
Possible repairs:
1)Replace the EGR valve motor.
2)Replace the EGR valve.
3)Replace the damaged aftertreatment component