P0231: Fuel pump secondary circuit low
The fuel pump is not getting the voltage it should. Usually a fuse, the relay, a pump connector or a pump drawing too much current.
| Code | P0231 |
|---|---|
| System | Engine and transmission |
| Group | P02xx, Fuel and injectors |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P0231 means
The secondary circuit carries the current from the relay to the pump. The ECU monitors that wire and here it sees too low a voltage when the pump should be running. If the pump does not get enough current it gives low pressure or stops, and the engine runs out of fuel.
Most common causes
- Blown fuel pump fuse
- Fuel pump relay with burnt contacts
- Corroded or loose pump connector near the tank
- Broken wire or poor ground between the relay and the pump
- Worn or sticking fuel pump
- Inertia fuel cut-off switch triggered, on cars that have one
Symptoms
- Engine warning light on
- Car will not start
- Engine cuts out or loses power when accelerating
- Long cranking
Can you drive with P0231?
With care If it starts and runs well you can drive carefully to a garage, but it may cut out suddenly. Avoid long trips and fast roads until it is checked.
Open the bonnetthe in-depth explanation
How to check it
With the ignition on, listen for the pump running for a few seconds near the tank. If the reader shows fuel pressure, watch it live: if it drops when accelerating or is below normal at idle, suspect the pump or its power supply.
How to read and clear P0231 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0231 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P022D The turbo intercooler bypass actuator control B has an open circuit
- P022E The intercooler bypass control B gives a lower signal than normal
- P022F The intercooler bypass control B gives a higher signal than normal
- P0230 Fuel pump primary circuit malfunction
- P0232 Fuel pump secondary circuit: high signal
- P0233 The fuel pump relay circuit has an intermittent fault
- P0234 Turbocharger or supercharger A overboost
- P0235 Turbo boost pressure sensor A: circuit fault
- P0200 Injector circuit malfunction
- P0201 Injector circuit malfunction, cylinder 1
- P0202 Injector circuit malfunction, cylinder 2
- P0203 Injector circuit malfunction, cylinder 3
What does code P0231 mean?
The secondary circuit carries the current from the relay to the pump. The ECU monitors that wire and here it sees too low a voltage when the pump should be running. If the pump does not get enough current it gives low pressure or stops, and the engine runs out of fuel.
Can you drive with P0231?
If it starts and runs well you can drive carefully to a garage, but it may cut out suddenly. Avoid long trips and fast roads until it is checked.
How do you clear P0231?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P0231 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
