P2108 critical

Throttle Actuator Control Module Performance

The P2108 code means the vehicle's onboard diagnostic system has detected: Throttle Actuator Control Module Performance. This is a critical severity code.

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Keep driving?: Short distances only
DIY difficulty: hard
Estimated cost: $100 - $700 (parts and labor)

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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

Monitor throttle position commanded vs actual with scan tool -- they should match within 2-3%
Clean electronic throttle body with approved cleaner -- remove heavy carbon deposits
Check throttle plate for smooth operation -- should open and close freely without binding
Inspect throttle body connector for intermittent connections or corrosion
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.