Fuel Pump "A" Control Circuit High

What it means

The engine computer (ECU) detected higher than expected voltage on the fuel pump control circuit, such as voltage present when the circuit should be off. This can mean the wire is shorted to a voltage source or the relay is stuck, so the pump keeps running or does not follow the computer's command.

Related codes: P0627P0628P0230P0088

Symptoms4

• Check engine light on.
• Pump still running after the engine is switched off in some cases.
• Dead battery after the vehicle sits.
• Occasional hard starting.

Possible causes5

• Welded contacts inside the fuel pump relay.
• Control circuit wire shorted to a voltage source.
• Moisture or corrosion in the relay box or connectors.
• Faulty fuel pump control module on vehicles that have one.
• Faulty control circuit inside the engine computer (rare).

How to diagnose5

1. Switch the engine off and listen whether the pump keeps running.
2. Swap in an identical known-good relay and see if the code clears.
3. Measure voltage on the control circuit with the key off; voltage present points to a short.
4. Inspect the wiring for contact with other power wires.
5. Measure battery drain with the vehicle off if the battery keeps going flat.

How to fix5

1. Replace the pump relay if its contacts are welded.
2. Repair the wire shorted to voltage and re-insulate it.
3. Clean moisture and corrosion from the connectors and relay box.
4. Replace the pump control module if proven faulty.
5. Clear the codes and confirm the pump stops when the engine is off and the code does not return.

The cost is low for a relay or wire repair, and rises if a pump control module is needed or the pump was damaged by running constantly.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions