P0231⛽ Fuel delivery (fuel pump power supply and feedback circuit)Stop and fix promptly

P0231: Fuel Pump Secondary Circuit Low (Meaning, Causes, Fixes)

Reviewed 2026-10-25 · Based on 2 cited source(s)

What P0231 means

The fuel pump gets its power through the fuel pump relay, which the powertrain control module (PCM) switches on. OBD-Codes.com explains that some vehicles have a feedback (secondary) circuit: a wire spliced into the fuel pump's voltage feed, usually near the PCM, that lets the PCM confirm the pump is really getting power. When the PCM turns the relay on, it expects to see battery voltage on that feedback wire. If the voltage is too low or missing, P0231 can set. RepairPal describes the code more broadly as the PCM (or, on most newer vehicles, a separate Fuel Pump Control Module) detecting an incorrect signal to or from the fuel pump. The sources lean different ways on the likely cause: OBD-Codes.com focuses on the relay, fuse and supply or feedback wiring, while RepairPal lists fuel pump failure first and fuel pump replacement as the common repair. P0230 covers the relay's control side, P0232 is the same secondary circuit reading high, and P0233 is the secondary circuit intermittent (RepairPal code list).

Severity: can I keep driving?

Stop and fix promptly

Get it diagnosed right away. RepairPal rates P0231 Urgent, meaning immediate action is needed. OBD-Codes.com gives no severity rating, but lists no-start, start-and-stall and inadequate fuel supply among the symptoms, and forum owners describe engines shutting off while driving. Don't plan long trips until it's checked, and pull over safely if the engine starts to cut out. OBD-Codes.com notes one exception: if the car runs normally with no drivability problems, the fault is often just the feedback wire to the computer.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. A bad fuel pump relay (OBD-Codes.com, RepairPal)
  2. A blown fuel pump fuse caused by a short to ground (OBD-Codes.com)
  3. Chafed harness causing an open in the fuel pump supply circuit (OBD-Codes.com); RepairPal lists wiring issues
  4. Loose or damaged connectors (OBD-Codes.com)
  5. An open in the feedback wire between the splice and the PCM (OBD-Codes.com)
  6. A failed fuel pump (RepairPal; OBD-Codes.com also reaches the pump at the end of its tests)
  7. A failed PCM (RepairPal)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. Find a wiring diagram for your vehicle first; OBD-Codes.com says there is no replacement for one when working on fuel pump circuits.
  2. If the engine starts and runs with no drivability problems, OBD-Codes.com says to suspect an open in the feedback wire between the PCM and the splice into the pump's supply wire.
  3. If the engine won't start or starts and dies, check the fuel pump fuse. If it's blown, OBD-Codes.com describes pulling the relay and checking resistance from the supply wire at the pump connector to ground; if the short goes away with the pump unplugged, the pump is shorted, and if it stays, the wiring is shorted.
  4. If the fuse is good, confirm battery voltage reaches the fuse and the relay. OBD-Codes.com then describes bridging the relay's power terminals (usually 30 and 87, but check the diagram) with a fused jumper: if the pump runs, replace the relay.
  5. If the pump still doesn't run with the jumper, check for voltage and a good ground at the pump connector at the tank. OBD-Codes.com says if both are present, the pump is the likely fault; if voltage is missing, repair the open in the supply wire.

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • The engine won't start or shuts off while driving
  • You don't have a wiring diagram or aren't comfortable jumping relay terminals or testing circuits
  • The fuse keeps blowing and you can't find the short
  • Testing points to the fuel pump in the tank or to the PCM
  • You smell fuel or see a fuel leak; stop and don't keep cranking the engine

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Does P0231 mean my fuel pump is bad?

Not necessarily. RepairPal lists fuel pump failure first and pump replacement as the common repair, but OBD-Codes.com points first at the relay, fuse and wiring, and only condemns the pump after it has confirmed power and ground at the pump connector. Test before buying a pump.

Can I drive with a P0231 code?

RepairPal rates it Urgent, and OBD-Codes.com lists no-start and start-and-stall among the symptoms. If the engine is cutting out, get it diagnosed before relying on it. If it runs normally, OBD-Codes.com says the fault is often just the feedback wire, but it should still be checked.

Why does P0231 show up on 6.0 and 7.3 Power Stroke trucks?

People do search for P0231 on Ford Power Stroke diesels, and OBD-Codes.com forum threads include Ford trucks and SUVs. Neither source gives a diesel-specific cause, so follow the same relay, fuse and wiring checks with a diagram for your truck.

What is the difference between P0230, P0231 and P0232?

P0230 is the fuel pump primary circuit (the relay control side). P0231 is the secondary circuit low and P0232 is the secondary circuit high, per RepairPal's code list. The secondary circuit is the pump's power feed that the PCM monitors.

How much does it cost to fix P0231?

Neither source gives a repair cost. A relay, fuse or wire repair is usually far cheaper than a fuel pump or computer, so get a diagnosis or written estimate before buying parts.

Sources

  1. OBD-Codes.com: P0231 Fuel Pump Secondary (Feedback) Circuit Low Voltage (Dale Toalston, ASE)
  2. RepairPal: P0231 Fuel Pump Secondary Circuit Low (rated Urgent)

Last reviewed 2026-10-25. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.