PACCAR PX-9 CM2350 (2013-17) Fault Code:3142 PID: SPN:4360 FMI:3 Aftertreatment 1 SCR Intake Temperature Sensor Circuit – Voltage Above Normal or Shorted to High Source

Reason:
Aftertreatment SCR Intake Temperature Sensor Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at the SCR intake temperature sensor circuit.

Effect:
Possible reduced engine performance.

Circuit Description:
The aftertreatment SCR (selective catalytic reduction) temperature sensor module is a smart device that communicates with the engine control module via the J1939 data link. The aftertreatment SCR temperature sensor module performs its own internal diagnostics and reports malfunctions back to the engine control module using the J1939 data link. The aftertreatment SCR temperature sensor module is used to measure the aftertreatment SCR intake temperature and aftertreatment SCR outlet temperature. The temperature probes are permanently attached to the aftertreatment SCR temperature sensor module and can not be replaced individually.

Component Location:
The SCR intake temperature sensor is located in the aftertreatment system. It is located between the diesel particulate filter and the SCR catalyst in the exhaust system.

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 SCR intake temperature sensor signal voltage was greater than 4.4-VDC for more than 2 seconds.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
2) Diesel exhaust fluid injection into the aftertreatment system is disabled.
3) 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 ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.

Shop Talk:
The SCR intake temperature sensor shares return wires in the engine harness with other sensors. An open return can cause multiple fault codes to be active.

Possible Causes:
1) Inactive fault codes
2) Faulty ECM