P2554
Throttle/Fuel Inhibit Circuit Low
- Severity
- High
- Driving
- Drive only to a garage
The throttle or fuel inhibit circuit is reading low - typically shorted to earth or an open circuit. Depending on how the circuit is arranged, the engine may be inhibited when it should not be, or the inhibit may not work at all.
Possible causes
- CommonWiring or connector fault on the inhibit circuit
- CommonFault in the immobiliser or security module driving the circuit
- CommonCorroded connector
- CommonAftermarket alarm, immobiliser or remote start spliced into the circuit
- PossibleChafed harness shorting against the body
- RareFailed control module input
What you might notice
- Engine will not start
- Engine cutting out
- Reduced power or forced idle
- Immobiliser or security warning light
- Check engine light on
What to check, in order
- Disconnect at one end and check whether the low reading persists at the harness.
- Ask whether an aftermarket alarm, immobiliser or remote start has been fitted. These are wired into exactly this kind of circuit and are a frequent cause of faults that appear weeks later.
- Read the immobiliser and security modules for their own codes.
- Inspect the connectors and wiring on the circuit.
- Watch the inhibit state on the live data screen with the engine running and with a valid key.
- Try the spare key. If one key works and the other does not, the fault is the key rather than the circuit.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Vehicle speed control, idle control and auxiliary inputs
P2500P2501P2502P2503P2504P2505P2506P2507P2508P2509P2510P2511P2512P2513P2514P2515P2516P2517P2518P2519P2520P2521P2522P2523P2524P2525P2526P2527P2528P2529P2530P2531P2532P2533P2534P2535P2536P2537P2538P2539P2540P2541P2542P2543P2544P2545P2546P2547P2548P2549P2550P2551P2552P2553P2554P2555P2556P2557P2558P2559P2560P2561P2562P2563P2564P2565P2566P2567P2568P2569P2570P2571P2572P2573P2574P2575P2576P2577