The computer has detected an electrical fault in the circuit that powers the fuel pump — not a fuel pressure problem exactly, but a wiring/relay/control problem in how the pump is switched on. Because the engine can't run at all without fuel delivery, this is one of the more urgent codes.
Symptoms
- Engine won't start, or starts briefly and then dies as fuel pressure drops
- No fuel pump priming sound (a brief hum) when turning the key to "on" before starting
- Intermittent stalling if the circuit fault is a loose connection rather than a full failure
- Engine may crank normally but simply never catch
Likely causes
- Blown fuel pump fuse
- Failed fuel pump relay — a very common and cheap-to-check cause
- Damaged, corroded, or disconnected wiring between the relay and the pump
- The fuel pump itself has failed electrically (distinct from simply being worn out mechanically)
How to diagnose it
- Check the fuel pump fuse first — it's the fastest thing to rule out
- Listen for the pump priming sound at the fuel tank when the key is turned to "on"; if silent, test the relay by swapping it with an identical one elsewhere in the fuse box
- With a multimeter, check for voltage at the pump connector when the key is on — no voltage points to wiring or the relay, voltage present but the pump still not running points to the pump itself
Typical fixes & cost
- Replace a blown fuse5–20 EUR
- Replace the fuel pump relay20–80 EUR
- Repair wiring, or replace the fuel pump if it's confirmed electrically dead200–700 EUR
Code names are compiled from open/standardized SAE and ISO references. Explanations, symptoms, causes and fixes are original. Covers generic (P0/C0/B0/U0) codes only — manufacturer-specific codes are planned for a future update.
AS
Reviewed by Artyom SemenovAutomotive Editor · Fact-checked by Yauheni Kapliarchuk, Editor-in-Chief