Throttle Actuator Control System -- Forced Idle
What does P2104 mean?
The P2104 code means the vehicle's onboard diagnostic system has detected: Throttle Actuator Control System -- Forced Idle. This is a critical severity code.
Common Symptoms
- Engine stuck at idle speed
- Accelerator pedal has no effect
- Reduced power warning light on dash
- Vehicle will not accelerate above idle
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Other throttle or pedal position codes causing forced idle Very High
- Electronic throttle body malfunction High
- Accelerator pedal position sensor failure High
- Wiring fault in throttle control system Moderate
- PCM internal failure in throttle control logic Low
Step-by-Step Diagnostic Procedure
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Check for additional throttle-related codes -- P2104 is usually a secondary code triggered by other faults
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Diagnose and repair any P2100-P2103, P2120-P2128, or P2135-P2140 codes first
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Test accelerator pedal position sensor signals with scan tool -- both tracks should respond to pedal
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Inspect electronic throttle body for mechanical binding or carbon buildup
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After repairing root cause, clear all codes and perform throttle relearn procedure
Frequently Asked Questions
Can I drive with code P2104?
No. The PCM has forced the engine to idle only as a safety measure. The vehicle will not accelerate. This code is the result of another throttle system fault that needs to be diagnosed and repaired first.
Why did the PCM force the engine to idle?
Forced idle is a safety response when the PCM detects a potentially dangerous condition in the electronic throttle system. Rather than risking unintended acceleration from a faulty throttle, the PCM locks the throttle at idle to keep the vehicle safe.
Will clearing codes fix P2104?
Temporarily, possibly. But P2104 is always caused by another underlying fault. If you clear codes without fixing the root cause, the forced idle condition will return almost immediately. Always check for and repair companion trouble codes first.