P218B
Throttle/Fuel Inhibit B Circuit
A general electrical fault on the throttle/fuel inhibit signal B — used by anti-theft, immobiliser, or transmission to forbid throttle/fuel until released.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Inhibit signal lostCommon
Parts involved
- Throttle Fuel Inhibit
- Immobiliser
P218B 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.