P2138 The two accelerator pedal sensors disagree

By: Diagno editorial team · Updated: 2026-10-15

P2138 means: The two accelerator pedal sensors disagree. This sensor tells the engine computer how far the throttle is open or how far the accelerator pedal is pressed. Drive gently and have the car checked soon. The repair usually costs about €80–450 in Estonia. The most common cause: throttle body is dirty or its sensor is worn.

What it means

This sensor tells the engine computer how far the throttle is open or how far the accelerator pedal is pressed. When it fails, the car often goes into limp mode and the throttle doesn't respond properly. The accelerator pedal has two sensors that must read the same. Usually the pedal is worn.

What could be wrong

1. 1Throttle body is dirty or its sensor is worn
2. 2Connector or wire
3. 3Accelerator pedal sensor is worn

What you can check yourself

Check the throttle body and accelerator pedal connectors. If the car went into limp mode, switch the ignition off for a couple of minutes and try again. You can check the simple things yourself, but the repair is best done in a workshop.

How we fix it

1. We check the sensor readings with a diagnostic tool
2. We clean the throttle body and re-learn it
3. We replace the throttle body or accelerator pedal

Standard SAE description: Throttle/Pedal Position Sensor D/E Voltage Correlation