Cummins ISB CM850 (2003-06) Fault Code: 155 (Marine) PID: 105 SPN: 105 FMI: 0 Intake Manifold 1 Temperature – Data Valid but Above Normal Operational 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 (Marine) PID: 105 SPN: 105 FMI: 0 Intake Manifold 1 Temperature – Data Valid but Above Normal Operational 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.

Possible repairs:

1)Reference the Intake Manifold Air Temperature Above Specification symptom tree in the ISBe and ISB (Common Rail Fuel System) Series Engines, Bulletin 4021271.