P0627: Fuel Pump A Control Circuit Open

What it means

The ECU detected an open circuit in the fuel pump A control output. With no pump operation the engine cannot run; this code is often paired with no-start and no fuel pressure.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Fuel Pump A is the pump control channel monitored by the ECM to supply fuel to the engine. P0627 is set when the ECM detects an open in that control output, so the pump may not run and fuel pressure may be absent, causing a crank-no-start or stall.

Common causes

Most likely first.

1. Fuel pump relay failed
2. Wiring open
3. Pin pushed back out of connector body

Symptoms

• Engine may crank but fail to start
• Engine may stall or lose power if fuel delivery is interrupted

How to diagnose it

1. Record freeze-frame data and check for fuel-pressure, pump, and security-related codes before attempting repeated starts.
2. Listen for the fuel pump's brief operating sound at key-on, while recognizing that silence alone does not prove an open circuit.
3. Inspect Fuel Pump A's fuse, relay, wiring, and connectors for a disconnected plug, pushed-back terminal, corrosion, or broken wire.
4. Check whether the relay receives its control command and whether power reaches the pump during the commanded prime.
5. Measure voltage and continuity through the Fuel Pump A control circuit and verify pump operation against the manufacturer's specification.

Common fixes

• Reconnect a loose pump connector or reseat a pushed-back terminal.
• Replace a failed Fuel Pump A relay or fuse after checking for the cause of failure.
• Repair an open in the pump-control wiring.
• Replace the fuel pump if it receives the correct command and power but does not operate.

Can I keep driving?

If the engine cranks without starting or has stalled, do not drive it; it may stop again without warning. Avoid repeated cranking, which can drain the battery, and arrange diagnosis where the vehicle is safely parked.