OBD CodesWhat it means
The electric fuel pump in or near the tank is switched by a relay or a control module. These codes are about that electrical supply, not about fuel pressure itself. If the pump loses power, the engine stops.
Codes in this group
| Code | Meaning |
|---|---|
| P0230 | Fuel pump primary circuit fault |
| P0231 | Fuel pump secondary circuit low |
| P0232 | Fuel pump secondary circuit high |
| P0627 | Fuel pump control circuit open |
| P0628 | Fuel pump control circuit low |
| P0629 | Fuel pump control circuit high |
Bank 1 is the side of the engine that has cylinder 1. Sensor 1 is before the catalytic converter and sensor 2 is after it. More terms explained.
What you may notice
- Engine cranks but will not start
- Engine cuts out while driving
- No humming sound from the tank when the ignition is switched on
Common causes
Most likely first:
- A failed fuel pump relay
- A blown fuse
- Corroded connector at the pump or tank
- A failing pump drawing too much current
- A tripped fuel cut-off (inertia) switch after a bump, on cars that have one
What to check first
- Turn the ignition on and listen near the tank for two seconds of humming
- Check the fuel pump fuse and relay named in the owner's manual
- Because the car may stop without warning, repair it before any long trip
Have a mechanic confirm. A fault code tells you which system reported a problem, not which part has failed. The same code can have several causes, and they differ between car models. Use this page to understand the code, then have a qualified mechanic test the car before any part is replaced.
After the repair
Once the cause is fixed, the code can be cleared with a scan tool, or the warning light goes out by itself after several trips without the fault. Clearing a code without fixing the cause only hides it for a while. More about clearing codes.
Related codes
Mass air flow (MAF) sensor (P0100), Manifold pressure (MAP) and barometric sensor (P0105), Intake air temperature sensor (P0110), Engine coolant temperature sensor (P0115), Thermostat and engine warm-up (P0125), Throttle position sensor (P0120), Accelerator pedal sensor and throttle agreement (P2120), Electronic throttle actuator (P2100). All codes.
Written in November 2026. These are generic OBD-II codes, the same on all makes. Causes and repair steps differ between models.