Circuit/System Testing
- Ignition OFF, disconnect the X2 harness connector at the FPCM relay.
- Ignition OFF, connect a DMM, set on the volt setting, between the PWM control circuit terminal 1 and ground.
- Ignition ON, command the ECM fuel pump ON with a scan tool. The DMM reading should be between 4.5-5.5 V.
- If less than the specified range, test the PWM control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the FPCM.
- If greater than the specified range, test the PWM control circuit for a short to voltage. If the circuit tests normal, replace the FPCM.
- If all circuits test normal, replace the FPCM relay.