P0124 Throttle position sensor: signal drops out at times ("A")

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

P0124 means: Throttle position sensor: signal drops out at times ("A"). 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: connector loose, damp or corroded.

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. The signal drops out now and then. The most common cause is a loose connector or a chafed wire.

What you may notice

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

What could be wrong

1. 1Connector loose, damp or corroded
2. 2Wire broken or chafed
3. 3Faulty sensor or throttle body
4. 4Engine computer fault (rare)

Repair difficulty: Moderate

What you can check yourself

First look at the connector and wiring: anything loose, melted or green with corrosion? 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 fault data on the diagnostic tool and check whether the fault is constant
2. We measure the circuit's supply, ground and signal
3. We repair the wire or replace the connector
4. If the wiring is fine, we replace the sensor or throttle body

Standard SAE description: Throttle Position Sensor/Switch A Circuit Intermittent