PACCAR PX-9 CM2350 (2013-17) Fault Code:155 PID:105 SPN:105 FMI:0 Intake Manifold 1 Temperature – Data Valid But Above Normal Operating Range – Most Severe Level

Reason:
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.

Effect:
Progressive power and/or speed derate increasing in severity from time of alert. If the Engine Protection Shutdown feature is enabled, the engine will shut down 30 seconds after the red STOP lamps starts flashing.

Circuit Description:
The Engine Control Module (ECM) provides 5 volts to the intake manifold temperature signal circuit, and monitors the change in voltage caused by changes in the resistance of the sensor to determine the intake manifold temperature. When the intake air is cold, the sensor (or thermistor) resistance is high. The ECM signal voltage only pulls down a small amount through the sensor to a ground. Therefore, the ECM senses a high signal voltage or low temperature. When the intake air is warm, the sensor resistance is low. The signal voltage pulls down a large amount. Therefore, the ECM senses a low signal voltage, or a high temperature.

Component Location:
The intake manifold 1 pressure/temperature sensor is located in the air intake horn.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the intake manfiold air temperature was greater than 132°C [270°F] for 5 seconds.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the red STOP ENGINE lamp immediately after the diagnostic runs and fails.
2) The torque output of the engine will be reduced.
3) Maximum engine operating speed will be decreased.
4) The engine will be shut down if the Engine Protection Shutdown feature is enabled.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
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