P2138 fault code: what it means

P2138: The two accelerator pedal position sensor signals disagree. Car usually goes into reduced-power mode.

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

worn sensor track in the accelerator pedal
corroded or wet pedal connector
damaged wiring between pedal and engine computer

P2138 by make

Ford

Pedal position sensor D/E voltage disagreement: the two accelerator pedal signals do not match. Common on BA/BF Falcon.

Usual causes: accelerator pedal sensor; 5 V reference dragged down by another sensor or switch; wiring

Hyundai

Accelerator pedal position sensor signals don't agree; often limp mode.

Usual causes: faulty accelerator pedal position sensor; wiring or connector fault; sensor corrosion

Not sure what P2138 means on your car? Ask Credov.

Before you clear it

Write the code down or photograph the scanner first. A code that comes straight back after clearing points to a fault that is still there. A car whose codes were cleared just before you arrived may be hiding one: the scanner's readiness monitors show "not ready" for a while after codes are cleared.

Researched by Credov from manufacturer and workshop sources. A fault code points to where a fault may be; a workshop confirms it with a diagnosis. Browse all fault codes.