P0231 on Ford: How to Diagnose & Fix
Fuel Pump Secondary Circuit - Low
1 Ford model · 1 documented issue · $200-$700 repair
P0231 on Ford by model: symptoms, diagnosis and fix
Gasoline F-350s of this era (5.4L Triton V8 and 6.8L Triton V10) use a Fuel Pump Driver Module bolted directly to the steel frame rail behind the rear axle, where it takes the full spray of road salt and water. The aluminum module against the steel frame sets up galvanic corrosion; the housing corrodes through, moisture reaches the circuit board, and the module stops driving the in-tank pump. The result is intermittent stalling, extended cranking or an outright no-start, often with FPDM circuit codes stored. Trucks in salt-belt states fail earliest. This is a chassis/electrical failure on the gas trucks only.
Common Symptoms
- Intermittent stalling
- Extended crank or no-start that comes and goes
- Loss of power under load
- Corroded module visible on the frame rail
How to Fix
Inspect the module on the frame rail for a swollen, cracked or white-corroded housing before condemning the in-tank pump. Replace the FPDM, and critically, clean the mounting surface and use dielectric grease on the connector; many owners relocate the module to a cleaner, drier surface or add a barrier between the module and the frame to break the galvanic path. Also inspect the pigtail for green corroded terminals, which will kill a new module. Separately, an erratic or stuck fuel gauge with a P0463 is a different problem, not an FPDM failure: it usually means the sender resistor card in the in-tank pump module, which is normally replaced complete. No recall covers the FPDM.
Sources for this issue (3)
P0231 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0231 mean on a 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 it is documented across 1 model: F-350.
What are the most common causes of P0231?
The most common causes of P0231 are: 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). The specific cause varies by vehicle.
How much does it cost to fix P0231 on a Ford?
Published repair estimates on Ford range from $200 to $700 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.