P2554Throttle/Fuel Inhibit A Circuit Low
- 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
- P2554 reports that the voltage on throttle/fuel inhibit circuit A is too low. In GM's 2005 L66 parameter sheet the limit is below 0.498 V on the analogue inhibit circuit, read by the powertrain module while it is still processing after the ignition has been switched off. The table lists a warm engine, coolant at 69.5 °C or more, among the enable conditions. Since the check takes place after shutdown, the lamp lights on the next drive rather than at once. A low reading usually comes from a short to ground somewhere in the inhibit wiring or a pull-down inside a connected unit. The relay itself is judged under P2553, an over-voltage on the same line under P2555, and P2552 is the general circuit fault. Drivers may meet a throttle that reacts sluggishly or a reduced-power mode.
- What you may notice
- Check engine light on the following drive
- Sluggish throttle response or reduced power
- Likely causes
- LikelyInhibit circuit shorted to ground
- PossibleConnected relay or control unit pulls the line down
- RareEngine module input stage defective
- 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.