Cummins ISB CM850 (2003-06) Fault Code: 155 (Auto) PID: 105 SPN: 105 FMI: 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.

Cummins ISB CM850 (2003-06) Fault Code: 155 (Auto) PID: 105 SPN: 105 FMI: 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 as it passes through the intake manifold.

Possible causes:

1)Restricted air flow through the charge-air cooler
2)Undersized charge-air cooler
3)High turbocharger compressor outlet temperature
4)For marine engines, verify the cooling water intake is not blocked or clogged with debris.

The sensor return configuration for Euro 4 ISB engines has been changed for automotive wiring harnesses manufactured from February 2012 onward. The new style wiring harnesses can be be identified using the method below:

1)Disconnect the ECM connector
2)Disconnect the camshaft position sensor
3)Disconnect the intake manifold pressure/temperature sensor
4)Check for continuity between the intake manifold pressure/temperature sensor RETURN pin and the camshaft position sensor RETURN pin
5)Check for continuity between ECM pin 47 and the camshaft position sensor RETURN pin
6)Use the table below to determine which harness is fitted to the engine.

NOTE: QSB engines, all C series engines, and all L series engines are not affected by this change.

Possible repairs:

1)Reference the Intake Manifold Air Temperature Above Specification symptom tree in the ISC, QSC8.3, ISL and QSL9 Engines, Bulletin 4021418 or ISBe and ISB (Common Rail Fuel System) Series Engines, Bulletin 4021271.