542 Fuel pump circuit open between the PCM and the motor ground
How to read it
Code 542 reads as 5 flashes, pause, 4 flashes, pause, 2 flashes on the check-engine light. Jumper the self-test input to signal return at the test connector, then run the key on engine off self test and the running self test, counting the check-engine flashes each time.
New to flash codes? The OBD-I code reading guide walks through the paperclip method, code 12, and reading two-digit codes.
What does Ford code 542 mean?
542. Fuel pump circuit open between the PCM and the motor ground. This code sets when your vehicle computer detects fuel pump circuit open between the pcm and the motor ground.
Common causes of 542
- Faulty fuel pump or fuel pump relay
- Open or shorted wiring in the fuel pump circuit
- Blown fuel pump fuse
- Faulty inertia switch
- Faulty PCM output
How to fix 542
- Confirm the code and listen for the fuel pump prime
- Check the fuel pump fuse and relay
- Inspect the fuel pump wiring and inertia switch
- Test the pump circuit for power and ground
- Replace the pump or relay only after the circuit test fails