What does it mean?
P1501 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Fuel Pump Relay Circuit Electrical Short to Ground .
Symptoms
- MIL on
- Fuel pump runs constantly with the key on, and in some cases even with the key off
- Battery drains overnight and the fuel pump gets hot
- Flooding or hard starting from continuous fuel pressure
- Fuel pump circuit fuse blows repeatedly
- The engine may still run normally, so the fault stays hidden until the battery goes flat
Likely causes
- Fuel pump relay control circuit shorted to ground
- Relay coil shorted internally
- Harness chafed and grounding against the body, firewall or a bracket
- Corrosion bridging pins inside the relay socket
- Water intrusion into the relay box or an underhood connector
- Module driver stuck low or damaged internally
- Non factory wiring, such as an alarm or immobiliser splice, tapped into the circuit
How to fix it
- Listen at the tank: a pump that keeps running with the key off is a strong clue
- Remove the relay and measure the control circuit resistance to ground
- Inspect the relay socket for corrosion, water and melted terminals
- Test the relay coil for an internal short
- Follow the harness looking for chafed sections, particularly near the firewall and mounting brackets
- Check for non factory splices in the fuel pump circuit and remove or correct them
- Repair the shorted wire or replace the relay, then verify the pump primes and shuts off correctly