P2100 critical

Throttle Actuator Control Motor Circuit Open

The P2100 code means the vehicle's onboard diagnostic system has detected: Throttle Actuator Control Motor Circuit Open. This is a critical severity code.

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Keep driving?: No -- stop driving
DIY difficulty: hard
Estimated cost: $200 - $700 (parts and labor)

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Common Symptoms

Reduced engine power or limp mode
Engine may not respond to accelerator pedal
Throttle warning light on
Engine idle only -- no acceleration
Check engine light on

Probable Causes (Ranked by Likelihood)

Open circuit in throttle actuator motor wiring Very High
Faulty electronic throttle body motor High
Disconnected throttle body connector High
Corroded throttle body connector pins Moderate
PCM throttle motor driver circuit failure Low

Step-by-Step Diagnostic Procedure

Inspect throttle body electrical connector for damage, corrosion, or disconnection
Measure throttle motor resistance across motor pins -- typical spec is 1-5 ohms
Check for open circuits in wiring from PCM to throttle body motor -- continuity should be present
Verify PCM is providing voltage to throttle motor pins when commanded -- should see battery voltage
If wiring is intact and motor resistance is out of spec, replace the electronic throttle body

Frequently Asked Questions

Can I drive with code P2100?

No. The vehicle will be in severe limp mode or may not accelerate at all. The electronic throttle body cannot open without the motor circuit, so the engine will only idle. Have the vehicle towed to a repair shop.

What is a throttle actuator control motor?

Modern vehicles use an electronic throttle body (drive-by-wire) where a small electric motor opens and closes the throttle plate instead of a physical cable. The PCM controls this motor based on accelerator pedal position and other inputs.

Can I clean the electronic throttle body to fix this?

Cleaning will not fix an open circuit. This code specifically indicates an electrical problem with the motor circuit, not a mechanical sticking issue. However, if the throttle body is being replaced, cleaning the intake manifold bore is good practice.