P0231 on Ford
Fuel Pump Secondary Circuit - Low
P0231 on Ford vehicles indicates fuel pump secondary circuit - low. Au7o has documented this code across 1 Ford model — most commonly on F-150. This code indicates the engine computer detected a low-voltage condition in the fuel pump's secondary (driver/output) control circuit. Many vehicles control the fuel pump through a relay or a dedicated driver module, and the computer monitors the voltage on that circuit to confirm the pump is being powered correctly. When the feedback voltage stays lower than expected, P0231 sets. Because the fuel pump supplies pressurized fuel to the injectors, this fault can cause hard starting, stalling, or no-start conditions. Typical repair costs on Ford range from $250 to $700, depending on the specific model and root cause.
Common Causes of P0231
- •Faulty fuel pump relay
- •Corroded or loose connector at the pump or relay
- •Damaged or shorted wiring in the pump power circuit
- •Poor ground for the fuel pump circuit
- •Failing fuel pump drawing abnormal current
- •Faulty fuel pump driver module
- •PCM/ECM internal driver fault (rare)
P0231 on Ford by Model
Ford F-150(1 issue)
- In-Tank Fuel Pump Failure — Whining, Hard Starting, Stalling Under Load, and No-Start1997-2004
The in-tank electric fuel pump on 1997-2004 F-150s wears out at high mileage (commonly 150k+), producing a loud whine from the tank, hard starting, and stalling that gets worse when the engine is warm or under load (climbing hills, towing). It often fails intermittently first, then leaves the truck as a crank-no-start. The dash fuel gauge can also read erratically as the sending unit in the same module fails. Note: always check the inertia (fuel shut-off) switch before condemning the pump.
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View P0231 across all makes →Frequently Asked Questions
What does P0231 mean on Ford?▼
P0231 stands for "Fuel Pump Secondary Circuit - Low." This code indicates the engine computer detected a low-voltage condition in the fuel pump's secondary (driver/output) control circuit. Many vehicles control the fuel pump through a relay or a dedicated driver module, and the computer monitors the voltage on that circuit to confirm the pump is being powered correctly. When the feedback voltage stays lower than expected, P0231 sets. Because the fuel pump supplies pressurized fuel to the injectors, this fault can cause hard starting, stalling, or no-start conditions. On Ford specifically, this code is documented across 1 model.
What causes P0231 on Ford vehicles?▼
Common causes on Ford: Faulty fuel pump relay, Corroded or loose connector at the pump or relay, Damaged or shorted wiring in the pump power circuit, Poor ground for the fuel pump circuit, Failing fuel pump drawing abnormal current. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0231 on a Ford?▼
Repair costs on Ford range from $250 to $700, depending on the specific model and root cause.
Which Ford models have P0231 documented?▼
Au7o has documented P0231 on 1 Ford model: F-150.