Trouble codes › P2135

P2135 Throttle/Pedal Position Sensor/Switch "A"/"B" Voltage Correlation

Throttle

P2135 means the two throttle position sensors disagree, so the engine computer limits power; usually a failing throttle body.

Electronic throttles have two position sensors that are supposed to agree. P2135 means the engine computer saw the two signals disagree, so it can't trust them. To be safe, it usually puts the engine in reduced power (limp) mode.

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

The car may suddenly lose power or limit its speed, which can be dangerous in traffic or merging. Drive only as needed to get it somewhere safe and get it fixed.

Common causes

  1. A worn or failing throttle position sensor inside the electronic throttle body (common)
  2. A dirty or failing electronic throttle body
  3. Wiring or connector problems at the throttle body (corrosion, loose pins)
  4. Less often, the accelerator pedal position sensor

Symptoms

  • Reduced power or limp mode, often with a warning light
  • Hesitation, surging or erratic idle
  • The engine won't rev above a low limit

Common on: Chevrolet Silverado 1500, GMC Sierra 1500, Ford Fusion, Chevrolet Tahoe, Chevrolet Suburban, GMC Yukon

Known problems: Ford electronic throttle body problems (2009-2013)

What to check first

  1. Inspect the throttle body connector and wiring; reseat the connector and look for corrosion or spread pins.
  2. Clean a dirty throttle body following your service information, then do the throttle relearn if your vehicle needs one.
  3. With a scan tool, watch both throttle position signals while slowly pressing the pedal: they should move smoothly and stay in step.
  4. Check for service bulletins: several makes have known throttle body problems and updated parts.

What does P2135 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 P2135

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Related codes

General guidance for P2135 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.