P0628Fuel Pump A Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- What 'fuel pump A control circuit' means differs by maker: at GM petrol engines it is the control line from the engine module to the fuel pump relay (high-side driver), at GM's LML diesel the lift pump, at Ford petrol engines with a pump driver module the secondary circuit from that module to the pump (reported as a duty cycle on a monitor line), and at Ford's 6.7 L diesel (F-650/750) the high or low side of the pump relay. P0628 means a short to ground: GM detects 0.5 Ω or less to ground with the driver on (8 of 10 samples at 250 ms; two trips in 2018, first trip in 2025); the driver then shuts off, the relay does not pull in and the pump stops. Ford's 6.7 L diesel reports a short to ground on the high side of the pump relay within 0.2 s. Ford petrol engines do not use P0628. A blown fuse is a frequent companion.
- What you may notice
- No start or stalling
- Pump does not run
- Blown fuse
- Check engine light on
- Likely causes
- LikelyControl wire to relay or pump shorted to ground (chafing)
- PossibleRelay coil shorted
- PossiblePump or pump module shorted internally (Ford high side)
- RareDriver in the engine module faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.