HomeTrouble CodesU0681

U0681 — Lost Communication Throttlepedal Position Sensorswitch D

Generic OBD-II · all makesNetwork / communication

Code U0681 indicates that the engine control module has lost communication with the accelerator pedal position sensor. This typically triggers a safety 'limp home' mode to prevent unintended acceleration or loss of throttle control.

Symptoms

What causes it — most likely first

1. Faulty Accelerator Pedal Position (APP) Sensor

Internal failure of the pedal sensor's electronic circuitry or a failed potentiometer.

2. Damaged Wiring Harness

Frayed, chafed, or broken wires between the pedal sensor and the control module.

3. Corroded or Loose Connectors

Poor electrical contact at the pedal connector or the PCM connector due to corrosion or vibration.

4. Blown Fuse

A blown fuse in the circuit providing power to the accelerator pedal sensor.

5. PCM/ECM Internal Failure

A failure within the control module's processing circuit for the pedal signal.

How it's diagnosed

  1. Perform a visual inspection of the accelerator pedal connector for security and corrosion.
  2. Inspect the wiring harness for visible damage, shorts, or signs of rodent interference.
  3. Check all relevant fuses providing power to the pedal sensor and control module.
  4. Use a multimeter to verify the reference voltage and ground at the pedal sensor connector.
  5. Perform a 'wiggle test' on the wiring harness while monitoring live data to identify intermittent opens or shorts.
  6. Verify sensor output signals using a scan tool or oscilloscope to ensure they match expected values.

Code facts & related codes

SystemNetwork / communication
StandardizationSAE generic — identical on every make

Frequently asked

Is it safe to drive with code U0681?

The vehicle is generally safe to drive to a repair facility, but performance will be severely limited by limp mode for safety reasons.

Does this code mean my PCM needs to be replaced?

No. While the PCM is listed as a cause, it is rarely the source of this problem; the issue is almost always the sensor itself or the associated wiring.

Can a dirty throttle body cause this code?

No. This code refers to the pedal sensor (the input), not the throttle body actuator (the output), though both are part of the electronic throttle system.