P0627 Code: Fuel Pump "A" Control Circuit/Open
The P0627 code means the fuel pump control circuit is open, so the pump does not get power when the computer commands it. It can make the engine crank without starting or stall. Check the fuse, relay, connector and wiring first.
- Severity
- High
- Can I keep driving?
- Yes, but with caution
- Estimated cost
- $30 to $900
- Difficulty
- Medium
- System
- Fuel Injection
- Applies to
- All OBD2 vehicles
On this page
What the P0627 code means
The computer turns on the fuel pump through a relay or a pump control module. When you turn the key on, it runs the pump for 2 or 3 seconds to pressurize the system, and it keeps the pump running while the engine turns.
The computer watches the control circuit from its own driver transistor. The P0627 code flags an open circuit: the component does not get current when it is commanded on. Before you replace the component, check the fuse, relay, connector and wiring, which are the most common causes.
If the control circuit fails, the pump may not run at all (the engine cranks but does not start) or it may run all the time (and drain the battery). On many vehicles the pump module sits under the rear seat or in the trunk, and it corrodes with moisture.
Measure the resistance of the component at its connector. If it is infinite, the component is open inside. If it is correct, follow the control wire back to the computer looking for a break, especially in the sections near the exhaust and at inline connectors.
P0627 code symptoms
- Check engine light on.
- The engine cranks but does not start.
- The engine stalls while driving or at a stop.
- No humming from the fuel pump when you turn the key on.
Likely causes of the P0627 code
- Unplugged connector or one with a broken lock.
- Open coil. Infinite resistance.
- Cut wire. Check the areas where the harness rubs.
- Blown fuse. Often caused by an earlier short.
How to diagnose the P0627 code step by step
- Activate the component with the scan tool and check whether it responds.
- Check the fuse and relay. Measure the voltage on both sides of the fuse, and swap the relay with an identical one.
- Measure the supply at the connector. You should see battery voltage with the key on or when the component is activated.
- Measure the resistance of the component and compare it with the manual. Also check the insulation to ground.
- Check the control wire for continuity to the computer and for shorts.
- Listen to the pump when you turn the key on. It should run for 2 to 3 seconds.
- Measure the fuel pressure.
How to fix the P0627 code
- Repair the connector, the wiring or the power supply.
- Replace the fuel pump control if it does not respond even with correct power and command signals.
- Clear the codes and verify the repair.
Technical reference data
- Typical pump current draw: 4 to 8 amps.
- Reference values: check the manufacturer data for your vehicle.
Brand-specific notes
The pump control module is a known weak point on several makes, so it is worth testing it early.
P0627 on Ford
On Ford, the fuel pump control module is a known failure.
P0627 on GM
On GM, the fuel pump control module is a known failure.
P0627 on Chrysler
On Chrysler, the fuel pump control module is a known failure.
Questions about the P0627 code
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