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P2103 – Throttle Actuator Control Motor Circuit High (OBD2)

P2103 means "Throttle Actuator Control Motor Circuit High". The voltage in the electronic throttle body circuit is above the permitted maximum. For most sensors this points to an open signal or ground wire – the signal "floats" up to the reference voltage – or to a short to voltage.

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P2103 quick summary

Fault codeP2103
MeaningThrottle Actuator Control Motor Circuit High
SystemPowertrain (Engine & Transmission)
VehiclesGeneric OBD2
SeverityHigh
Can I drive?Only carefully. The car may be in limp mode with very little power, or the engine may stall. Avoid overtaking and motorways until it is repaired.
Repair cost€0 – €600

How the electronic throttle (drive-by-wire) works

The electronic throttle body opens the throttle valve with an electric motor on command from the engine control unit; these codes mean the throttle motor, its control or its monitoring has a fault, or the control unit has forced a safety mode.

On drive-by-wire engines there is no cable between the accelerator pedal and the throttle. The pedal sensors tell the control unit what the driver wants, and the control unit drives a small DC motor in the throttle body against a return spring. Two throttle position sensors report the actual valve position back.

Because the throttle controls engine power, the system is monitored very strictly. If the commanded and actual positions disagree, the motor draws the wrong current or the valve sticks, the control unit stores a code and switches to a safety mode: forced idle, limited power, limited rpm or even engine shutdown (P2104–P2110). The EPC or Check Engine light comes on.

Common causes are carbon build-up around the throttle valve, a worn motor or gears in the throttle body, corroded connectors, water ingress, a weak battery and a throttle adaptation that was not performed after cleaning or replacement.

Symptoms of P2103

  • EPC or Check Engine light on
  • Limp mode – the car barely accelerates
  • Idle too high, too low or unstable
  • Engine stalls or hesitates
  • Delayed response to the accelerator pedal

Most common causes of P2103 (most likely first)

Mechanic's Pro Tip

Never push a drive-by-wire throttle valve open with your finger while the ignition is on – the motor can be damaged. Clean it with the ignition off and always run the adaptation afterwards.

  1. 1.Open circuit in the signal or ground wire

    Most likely

    A loose ground connection is a very common cause.

  2. 2.Signal wire shorted to the 5 V reference or battery voltage

  3. 3.Faulty electronic throttle body

  4. 4.Dirty or sticking throttle valve

    Carbon deposits stop the valve from closing or moving smoothly.

  5. 5.Worn throttle motor, gears or position sensor

    The throttle body is usually replaced as a unit.

  6. 6.Corroded connector or damaged wiring

  7. 7.Throttle adaptation not performed after cleaning, replacement or battery disconnection

Step-by-step diagnostic guide

  1. 1

    Read codes and throttle data

    Read all codes and compare commanded and actual throttle angle and both throttle sensor signals in live data with the ignition on and the engine idling.

  2. 2

    Check signal and ground

    With the ignition on and the electronic throttle body plugged in, back-probe the signal and ground wires. A signal stuck at reference or battery voltage points to an open ground/signal wire or a short to voltage.

    Multimeter: Ground wire to battery negative: below about 0.1 V. Signal stuck at about 5 V (or 12 V) = open or short to voltage.

  3. 3

    Inspect and clean the throttle

    With the ignition off, remove the intake hose and check the throttle valve for carbon. Clean it with throttle cleaner without forcing the valve open by hand against the motor.

  4. 4

    Check connector, supply and ground

    Check the throttle connector for corrosion and measure the motor control and sensor supply.

    Multimeter: Throttle position sensors: 5 V reference; signals usually moving in opposite directions or with a fixed offset (for example about 0.5–4.5 V).

  5. 5

    Run the throttle adaptation

    Run the throttle body adaptation (basic setting) with the scan tool – ignition on, engine off, pedal not pressed.

  6. 6

    Replace and adapt

    If the adaptation fails or the motor does not follow the command, replace the throttle body and run the adaptation again.

Frequently asked questions

Can I keep driving with P2103?

Only carefully. The car may be in limp mode with very little power, or the engine may stall. Avoid overtaking and motorways until it is repaired.

How much does it cost to fix P2103?

Typical repair costs are 0 € – 600 €, depending on the cause and the vehicle. The most common fixes are: open circuit in the signal or ground wire; signal wire shorted to the 5 V reference or battery voltage; faulty electronic throttle body. Always confirm the cause with the tests above before buying parts.

Why does my car have no power with a throttle code?

The control unit deliberately limits power for safety when it cannot trust the throttle. Once the fault is fixed and the codes cleared, full power returns.

Can a dirty throttle body cause these codes?

Yes, especially codes for throttle performance and idle position. Cleaning plus a throttle adaptation often fixes it.

What is the difference between P2103 and similar codes?

P2103 belongs to a group of codes for the same component that differ in the type or location of the fault: P2100 – Throttle Actuator Control Motor Circuit/Open; P2101 – Throttle Actuator Control Motor Range/Performance; P2102 – Throttle Actuator Control Motor Circuit Low; P2104 – Throttle Actuator Control System - Forced Idle; P2105 – Throttle Actuator Control System - Forced Engine Shutdown; P2106 – Throttle Actuator Control System - Forced Limited Power. The tests on this page apply to the whole group; the type of fault tells you where to start.

Related fault codes

This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.