Trouble codes › P2138

P2138 Throttle/Pedal Position Sensor/Switch "D"/"E" Voltage Correlation

Throttle

P2138 means the two accelerator pedal sensors disagree, so the engine computer limits power; usually a failing pedal assembly.

The two accelerator pedal sensors (D and E on most vehicles) disagree, so the engine computer can't trust how far you're pressing the pedal and usually limits power.

Can I keep driving? Not if you can avoid it.

Expect limp mode, possibly suddenly. Drive only as needed and get it fixed.

Common causes

  1. A worn or failing accelerator pedal assembly
  2. A corroded or loose connector at the pedal
  3. Damaged wiring
  4. A shared 5-volt reference problem

Symptoms

  • Limp mode, poor acceleration
  • Engine slow to respond to the pedal
  • Check-engine light

What to check first

  1. Check the pedal connector for corrosion and loose pins.
  2. Watch both pedal sensor readings while pressing slowly; they should move smoothly and stay in step.
  3. Check reference voltages and grounds.
  4. Replace the pedal assembly if the sensors disagree.

What does P2138 mean on your vehicle?

The likely cause depends on your engine. iRepair researches your exact year, make, model and engine (service bulletins, recalls and owner reports) and tells you what to check first. Your first 3 questions are free.

Ask iRepair about P2138

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Related codes

General guidance for P2138 on most vehicles. Some makers use the same code a little differently; confirm in the service information for your vehicle, put safety first, and see a professional when in doubt.