PACCAR PX-9 CM2350 (2013-17) Fault Code:3539 PID: SPN:51 FMI:3 Engine Intake Throttle Actuator Position Sensor Circuit – Voltage Above Normal or Shorted to High Source

Reason:
Engine Intake Throttle Actuator Position Sensor Circuit – Voltage above normal, or shorted to high source. High signal voltage detected at the engine intake air throttle position sensor circuit.

Effect:
Possible reduced engine performance.

Circuit Description:
The engine control module (ECM) controls the engine intake air throttle actuator. The ECM can open and close the throttle based on the operating condtions in order to regulate air flow to the engine.

Component Location:
The engine intake air throttle actuator is mounted in the piping between the charge air cooler and intake manifold.

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 engine intake air throttle position sensor circuit voltage was out of range high.

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) Engine intake air throttle actuation will be disabled. The engine intake air throttle will default to the open position.
3) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
4) 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, 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 amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) 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.
5) 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:
N/A

Possible Causes:
1) A malfunctioning engine intake air throttle position sensor
2) A short circuit to battery in the engine harness
3) An open circuit in the engine harness