P0628 code meaning
Fuel Pump A Control Circuit Low
Powertrain system Generic code P06xx codes Check engine light
What P0628 means
What 'fuel pump A control circuit' means differs by maker: at GM gasoline 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 gasoline 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 gasoline engines do not use P0628. A blown fuse is a frequent companion.
P0628 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P0628
- No start or stalling
- Pump does not run
- Blown fuse
- Check engine light on
Common causes of P0628
- Most likelyControl wire to relay or pump shorted to ground (chafing)
- PossibleRelay coil shorted
- PossiblePump or pump module shorted internally (Ford high side)
- Less likelyDriver in the engine module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel pump relayFuel pump driver moduleFuel pumpEngine control module
What each part of P0628 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 6 | Area: computer (engine control module) and output circuits. |
| 28 | The exact fault in that area. |
What to do next
- Note P0628 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0628
What does P0628 mean?
P0628 means "Fuel Pump A Control Circuit Low". What 'fuel pump A control circuit' means differs by maker: at GM gasoline 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 gasoline 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0628?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0628 fail an emissions test?
Yes, it can. P0628 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0628 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0628 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.