Throttle Actuator Control Module Performance
What does P2108 mean?
The P2108 code means the vehicle's onboard diagnostic system has detected: Throttle Actuator Control Module Performance. This is a critical severity code.
Common Symptoms
- Reduced engine power or limp mode
- Slow throttle response
- Intermittent loss of acceleration
- Throttle warning light on dash
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Electronic throttle body responding too slowly Very High
- Carbon buildup causing throttle plate to stick High
- Weak throttle actuator motor (worn brushes) Moderate
- PCM software issue or calibration error Moderate
- Intermittent wiring connection to throttle body Low
Step-by-Step Diagnostic Procedure
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Monitor throttle position commanded vs actual with scan tool -- they should match within 2-3%
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Clean electronic throttle body with approved cleaner -- remove heavy carbon deposits
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Check throttle plate for smooth operation -- should open and close freely without binding
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Inspect throttle body connector for intermittent connections or corrosion
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Check for PCM software updates (TSBs) that recalibrate throttle response parameters
Frequently Asked Questions
Can I drive with code P2108?
You can drive short distances, but the vehicle may have significantly reduced power and slow throttle response. The PCM has detected that the throttle is not responding as quickly or accurately as required.
Can cleaning the throttle body fix this code?
Yes, in many cases. Carbon buildup on the throttle plate and bore causes slow throttle response that triggers this performance code. Clean the throttle body, perform a throttle relearn, and clear codes. If the code returns, the throttle body motor may be worn.
What is the throttle relearn procedure?
After cleaning or replacing the throttle body, the PCM needs to relearn the throttle positions. This typically involves turning the key on for 30 seconds without starting, then starting the engine and letting it idle for 3-5 minutes with all accessories off. Some vehicles require a scan tool procedure.