Electronic Control System Signature, ISX and QSX15 Engines – FAULT CODE 131

Accelerator Position Sensor Circuit


Fault Code: 131
PID: P091
SPN: 91
FMI: 3/3

High voltage detected at accelerator position sensor.

Severe derate (power and speed). Limp home power

Accelerator Position Sensor Circuit

Circuit Description

The accelerator position sensor is attached to the accelerator pedal. The accelerator position sensor sends a signal to the electronic control module (ECM) when the driver pushes on the accelerator pedal. The accelerator position circuit contains three wires: (+) 5-VDC supply, return ground, and signal.

Component Location

The accelerator position sensor is located on the accelerator pedal.

Shop Talk

If all wiring and sensor checks look good, then replace the accelerator position sensor and the idle validation switch circuit wires between the accelerator pedal and the ECM with new wires. Run the wires through or around the bulkhead, without using the bulkhead connector. Test the truck with the test wires in place. If the fault goes away, replace the OEM harness. Seal the openings in the bulkhead around the connector and wires to prevent toxic and noxious fumes from entering the operator area.

The three wires in the accelerator position sensor circuit
must be twisted together. The same applies for the three wires in the idle validation switch circuit.

Refer to Troubleshooting Fault Code t05-131.

Last Modified:  26-Oct-2010