P2554
Throttle/Fuel Inhibit A Circuit Low
Throttle/fuel inhibit A reads stuck low — short to ground or permanently asserted. ECM may treat it as continuous inhibit and refuse normal operation.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Inhibit wire shorted to groundCommon
- Connector pins corroded - high contact resistanceLess likely
- Harness chafing through insulationLess likely
Parts involved
- Throttle Inhibit A
P2554 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.