P2102 Throttle actuator: signal or voltage too low ("A")

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

P2102 means: Throttle actuator: signal or voltage too low ("A"). The electronic throttle opens and closes the air path into the engine. Drive gently and have the car checked soon. The repair usually costs about €60–300 in Estonia. The most common cause: connector loose, damp or corroded.

What it means

The electronic throttle opens and closes the air path into the engine. The computer found that it doesn't move as commanded and often puts the car in limp mode. The signal voltage is too low. Usually a wire is broken, a connector is loose or a wire is shorted to ground.

What you may notice

• Engine light on
• Limp mode
• The engine doesn't respond to the pedal properly
• Idle too high or too low

What could be wrong

1. 1Connector loose, damp or corroded
2. 2Wire broken or shorted to ground
3. 3Faulty 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 whether the throttle body is dirty inside. After cleaning, the throttle has to be relearned with a diagnostic tool. 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 throttle body

Standard SAE description: Throttle Actuator "A" Control Motor Circuit Low