PACCAR PX-9 CM2350 (2013-17) Fault Code:134 PID:372 SPN:974 FMI:4 Remote Accelerator Pedal or Lever Position Sensor 1 Circuit – Voltage Below Normal or Shorted to Low Source

Reason:
Remote Accelerator Pedal or Lever Position Sensor 1 Circuit – Voltage Below Normal or Shorted to Low Source. Low voltage detected at remote accelerator position signal circuit.

Effect:
Remote accelerator will not operate.

Circuit Description:
The remote accelerator position sensor is a potentiometer attached to the remote accelerator lever. The remote accelerator position sensor varies the signal voltage to the engine control module (ECM) as the remote accelerator lever is depressed and released. Low signal voltage is received by the ECM when the remote accelerator lever is at 0 percent. A high signal voltage is received by the ECM when the remote accelerator is at 100 percent. The remote accelerator pedal position circuit contains a remote accelerator pedal position 5 volt supply, remote accelerator pedal position return, and remote accelerator pedal position signal.

Component Location:
The remote accelerator pedal or lever location varies with each original equipment manufacturer (OEM). Refer to the OEM service manual.

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 remote accelerator pedal signal voltage less than 0.132-VDC for more than 20 seconds.

Action Taken When the Fault Code is Active:
The ECM illuminates the red STOP ENGINE lamp immediately after the diagnostic runs and fails.

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:
If troubleshooting an intermittent accelerator problem:
The remote accelerator pedal or lever position sensor signal voltage can be monitored with INSITE™ electronic service tool, while flexing the harness to locate the intermittent connection. Intermittent connections will show up as abrupt changes in signal voltage displayed by INSITE™ electronic service tool.

Possible Causes:
1) Remote accelerator pedal or lever position signal shorted to engine ground or return wires in the OEM harness or sensor
2) Damaged remote accelerator pedal or lever position sensor
3) Open circuit in the remote accelerator signal, supply, or return wire in the harness or connectors.

NOTE: The three wires in the remote accelerator position sensor circuit must be twisted together.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM. For intermittent power supply and datalink communication issues with Aftertreatment Components, it is highly recommended that the OEM Power Distribution Center fuses and relays be thoroughly checked for loose, missing or intermittent connections.