P0231 — Fuel Pump Primary Circuit Malfunction
Drivable short-term, but fix now to avoid damage.
What P0231 means
This code means the engine computer detected low voltage or a malfunction in the primary circuit that controls the fuel pump relay or pump driver. Since this circuit is responsible for switching the fuel pump on, a fault can cause stalling, hard starting, or a complete no-start. Common fixes include replacing the fuel pump relay, repairing wiring and grounds, or replacing the pump driver module.
Common symptoms
- Check engine light is on
- Engine cranks but is slow to start or won't start
- Engine stalls while driving or at idle
- Hesitation or lack of power under acceleration
- Intermittent running problems
Common causes
- Faulty fuel pump relay
- Short to ground or low voltage in the primary wiring
- Corroded or loose electrical connectors
- Failed fuel pump driver module
- Poor ground connection or blown fuse
Typical repair cost
$150 – $700
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0231 code?
If the car runs normally you can usually drive short distances, but this is a fuel pump control fault that can cause stalling or a no-start. Avoid long trips and get it checked soon to avoid being stranded.
How much does it cost to fix a P0231 code?
Most repairs fall between $150 and $700. Replacing a relay or fixing wiring is cheaper, while a pump driver module or full fuel pump replacement raises the cost.
Is a P0231 code serious?
Yes. Because it affects the fuel pump's control circuit, it can leave you with a car that won't start or stalls unexpectedly, so it deserves prompt attention.
Does P0231 always mean a bad fuel pump?
Not necessarily. The code points to the control circuit, so the cause is often a relay, wiring, or driver module rather than the pump itself. A proper voltage test helps pinpoint the real culprit.