Cummins ISX CM870 (2003-06) Fault Code: 155 PID: P105 SPN: 105 FMI: 0/0 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.

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? CD-ROM, 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.