P1120 Accelerator pedal position sensor: circuit fault

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

P1120 means: Accelerator pedal position sensor: circuit fault. There are usually two throttle or accelerator pedal position sensors and they must agree. Drive gently and have the car checked soon. The repair usually costs about €60–450 in Estonia. The most common cause: dirty throttle body or worn sensor.

What it means

There are usually two throttle or accelerator pedal position sensors and they must agree. The computer found a wrong signal or the two don't match.

This is a make-specific code (Toyota). The exact meaning can vary by model and year.

What you may notice

• Engine light on
• Limp mode with no power
• Throttle response is delayed
• Idle hunts

What could be wrong

1. 1Dirty throttle body or worn sensor
2. 2Worn accelerator pedal sensor
3. 3Corroded connector
4. 4Broken wire

Repair difficulty: Moderate

What you can check yourself

Check the throttle body and pedal connectors. Cleaning the throttle body often helps. You can check the simple things yourself, but the repair is best done in a workshop.

How we fix it

1. We read the sensor on the diagnostic tool and compare it with other sensors
2. We check the connector, supply and ground
3. We repair the wiring or replace the sensor or throttle body

Standard SAE description: Accelerator Pedal Position Sensor Circuit