Throttle Actuator Control System — Forced Engine Shutdown
The TAC monitor commanded an engine shutdown because throttle authority can no longer be guaranteed safely. The most aggressive TAC limp mode — used when both throttle position sensors disagree or the motor is uncontrollable.
Affected components
- Throttle actuator control
- Throttle position sensor
- Ecm
Common causes
- High likelihood: TPS1 and TPS2 disagree beyond limit
- Medium likelihood: Throttle motor not controllable
Possible symptoms
- Check engine light on
- Reduced throttle response, possible limp mode
- Hesitation or surging
- Idle too high or too low
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
- Reduced-power or limp mode may occur
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.