P2555Throttle/Fuel Inhibit A Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2555 indicates excess voltage on throttle/fuel inhibit circuit A. The same 2005 GM document for the L66 V6 uses two limits depending on key state: more than 10 V while the ignition is on, or more than 4.5 V once it is off, with the fault judged after 4 s. As with its sibling checks, monitoring happens after shutdown, a single time per drive cycle, and the lamp waits until the next trip. A line that should be at a low level reading close to system voltage hints at a short to a battery-fed wire, a relay stuck closed or a lost ground on the receiving side. P2554 is the low-voltage counterpart, P2553 the relay function check and P2552 the general circuit fault. CARB requires makers to monitor electronic inputs of this kind for out-of-range values. Effects can include limited throttle or reduced power.
- What you may notice
- Check engine light on the next trip
- Limited throttle opening or reduced power
- Likely causes
- LikelyInhibit circuit shorted to a battery-fed wire
- PossibleInhibit relay stuck closed
- RareMissing ground on the receiving side
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €40 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.