PACCAR PX-9 CM2350 (2013-17) Fault Code:2973 PID:102 SPN:102 FMI:2 Intake Manifold 1 Pressure – Data Erratic, Intermittent, or Incorrect

Reason:
Intake Manifold 1 Pressure – Data Erratic, Intermittent, or Incorrect. The intake manifold pressure reading is erratic or not rational.

Effect:
Possible reduced engine performance.

Circuit Description:
The engine control module (ECM) provides a 5 volt supply to the intake manifold pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The intake manifold pressure sensor provides a signal to the ECM on the intake manifold pressure sensor signal circuit. This sensor signal voltage changes based on the pressure in the intake manifold.

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

Conditions for Running the Diagnostics:
This diagnostic consists of two parts:
One part runs immediately after the keyswitch is turned OFF, and the engine coolant temperature is above 70°C or 158°F. The second part occurs when the engine is operating.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the intake manifold pressure sensor was reading higher or lower than expected at keyoff or during normal engine operation.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) A default value of the intake manifold pressure reading is used.
3) Diesel exhaust fluid injection into the aftertreatment system is disabled.
4) Active and stationary regeneration of the diesel particulate filter will be disabled.
5) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
6) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1) To validate the repair, first ensure the engine coolant temperature is above 70°C or 158° F. Operate the engine if necessary.
2) Cycle the keyswitch to the ON position for 30 seconds, then cycle the keyswitch to the OFF position for 30 seconds. Start the engine and let it idle for 1 minute.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
5) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
6) 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:
Possible Causes:
1) A damaged turbocharger speed sensor
2) A damaged barometric pressure sensor
3) Leaks in the air intake system between the turbocharger and intake manifold
4) Restriction in the charge-air cooler
5) A damaged intake manifold pressure sensor
6) A damaged turbocharger compressor intake temperature sensor