Make: Cummins
Engine: ISM CM875 (2003-06)
Fauld Code: 155
PID: P105
SPN: 105
FMI: 0/0
Description: Intake Manifold 1 Temperature – Data Valid But Above Normal Operating Range –
Most Severe Level. Intake manifold air temperature signal indicates intake manifold air
temperature above engine protection critical limit.
Troubleshooting:
The intake manifold air temperature sensor measures the temperature of the charge air (fresh
air compressed by the turbocharger, cooled by the charge air cooler, and mixed with EGR) as it
passes through the intake manifold. This fault code is activated if the intake manifold air
temperature is above 132°C [270°F].
NOTE: Prior to running the 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 06050302.
ISX engines with CM870 (engines built before January 2004) require no changes at this time.
This is a warrantable calibration change.
Possible causes:
1)Plugged charge air cooler fins
2)Restricted airflow through the charge air cooler
3)Failed EGR differential pressure sensor, or leaks in sensor tubes
4)Undersized charge air cooler
5)High turbocharger compressor outlet temperature
6)Fouled EGR cooler
7)Stuck EGR valve.
Possible repair:
1)Replace the charge air cooler with the correct size unit.
2)Clean or replace the EGR differential pressure sensor adapter.
3)epair or replace the intake manifold air temperature sensor.
4)Replace the EGR Cooler.
Make: Cummins
Engine: ISM CM875 (2003-06)
Fauld Code: 187
PID: S232
SPN: 1080
FMI: 4/4
Description: Sensor Supply 2 Circuit – Voltage Below Normal or Shorted to Low Source. Low
voltage detected at the sensor supply number 2 circuit.
Troubleshooting:
Low voltage on the +5 volt supply line can be caused by a short circuit to ground in a supply
line, a short circuit between a supply line and a return line, a malfunctioning sensor, or a
malfunctioning ECM power supply.
During the fault code response test outlined for each sensor connected to sensor supply
number 2, Fault Code 187 must be active before unplugging each sensor. If the fault code is
not active, but can be easily duplicated by operating the engine, the following can be
performed:
Operate the engine under the conditions that will cause Fault Code 187 to become active, even
if it logs for a short period of time. Unplug one sensor at a time until Fault Code 187 stops
logging under the test conditions. Each sensor can be unplugged with the engine running.
Note: The engine may not start if the camshaft position sensor is unplugged.
Possible repair:
1)Replace the camshaft position sensor.
2)Replace the intake manifold pressure/temperature sensor.
3)Replace the EGR valve position sensor.
4)Replace the EGR differential pressure sensor.
5)Replace the rail fuel pressure sensor.
6)Replace the exhaust gas pressure sensor.
7)Repair or replace the engine harness.
8)Replace ECM.
Make: Cummins
Engine: ISM CM876 (2007-09)
Fauld Code: 1866
PID: 411
SPN: 411
FMI: 2
Description: Exhaust Gas Recirculation Valve Delta Pressure – Data Erratic, Intermittent, or
Incorrect. An error in the EGR delta pressure signal was detected at initial key-on or the sensor
failed the autozero test.
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 check is only performed at keyswitch OFF, during the ECM powerdown. During this
diagnostic check, the ECM monitors the value of the EGR differential pressure sensor. If this
value is outside of a specified range, Fault Code 1866 is set active.
Possible causes:
1)A damaged EGR differential pressure sensor.
2)High resistance in the wiring harness on the signal or return wire.
Possible repairs:
1)Remove and clean both EGR differential pressure tubes. Install and tighten the fittings, or
replace the EGR differential pressure tubes.
2)Clean the connector and pins.
3)Repair or replace the engine harness.
4)Replace the ECM.