Reason:
Auxiliary Temperature Sensor Input 1 Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at the Original Equipment Manufacturer (OEM) auxiliary temperature circuit.

Effect:
None on performance

Circuit Description:
The OEM has the option of wiring a temperature sensor input to the Cummins® ECM. A specific calibration is then created to recognize this temperature sensor input.

Component Location:
The OEM temperature sensor input and location will vary. Refer to the OEM service manual for sensor location.

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

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the OEM temperature sensor circuit is open or shorted high.

Action Taken When the Fault Code is Active:
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, 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) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
N/A

Possible Causes:
1) Open return circuit in the harness, connectors, or sensor
2) Open signal circuit or shorted to a voltage source