Trouble code · Powertrain · Generic (all makes)

P2135 Throttle/Pedal Position Sensor 'A'/'B' Voltage Correlation

The electronic throttle has two position sensors that should agree. Their readings don't match, so the computer can't be sure where the throttle is.

Safe to drive?
Drive with caution
Get it fixed soon
Scanner you need
Any OBD2 scanner
Even a basic code reader shows it
NHTSA complaints quoting it
69
Vehicle complaints, 2015–2025

Common causes

  • Worn throttle position sensor (usually inside the throttle body)
  • Damaged wiring or connector
  • Poor ground
  • Sometimes the accelerator pedal sensor

Symptoms

  • Reduced-power or limp mode
  • Hesitation
  • Stalling
  • The car won't rev past a low RPM

Can I drive with it?

The car usually limits power to keep you safe. Drive only as far as you need to and get it checked.

Tip: Wiggle the throttle body connector with the engine idling – if the idle changes or the light comes on, it's a wiring problem.

Which scanner reads it?

Any OBD2 scanner reads it. Live data shows both sensor voltages so you can see where they disagree.

Budget tools like the ANCEL AD310 read it; tools with live data and graphing – like the BlueDriver or OBDLink MX+ – help you find the cause. Not sure which fits you? Try the Find My Scanner quiz.

In the data

Of the vehicle complaints owners filed with NHTSA from 2015 to 2025, 69 quote P2135 – most often from Chevrolet, Ford, GMC owners. Complaints lean toward serious problems, so treat this as a sign of how often the code turns up in real reports, not how often cars get it.

Both sources are compared on the Trends page.

General information to help you understand a code – not a diagnosis. Your car’s service information or a qualified mechanic has the final word. See how we research.