P2112
Throttle Actuator Control System — Stuck Closed
The throttle plate cannot be commanded open. The engine stays at idle or stalls under load. Often caused by a seized motor, broken gear, or heavy carbon coking inside the throttle bore.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Reduced throttle response, possible limp mode
- Hesitation or surging
- Idle too high or too low
Common causes
Ordered by how often each turns out to be the cause.
- Throttle plate seized closedCommon
- Throttle motor seized or gear brokenPossible
- Carbon or debris buildup preventing free movementLess likely
Parts involved
- Throttle Body
- Throttle Actuator Motor
P2112 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.