Circuit/System Testing
- Ignition OFF, disconnect the X-420 harness connector at the rear of the fuel tank.
- Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal J and ground.
- If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
- Ignition OFF, connect a test lamp between the control circuit terminal D and the ignition voltage circuit terminal J.
- Ignition ON, use a scan tool to command the EVAP vent solenoid valve ON and OFF. The test lamp should turn ON and OFF.
- If the test lamp remains ON all the time, test the control circuit for a short to ground. If circuit/connections test normal, replace the ECM.
- If the test lamp remains OFF all the time, test the control circuit for a short to voltage or an open/high resistance. If circuit/connections test normal, replace the ECM.
- Test for 2.6-4.6 volts between the control circuit terminal D and ground.
- If the voltage is not within the specified range, replace the ECM.
- Remove the EVAP canister. Refer to Evaporative Emission Canister Replacement .
- Inspect the EVAP vent solenoid valve circuits in the fuel tank harness, between the EVAP vent solenoid valve connector and X-420 for the following conditions, and repair as necessary:
- Damaged wiring or terminals
- Open circuits
- Short to ground
- Wire to wire short
- If all circuits/connections test normal, test or replace the EVAP vent solenoid valve.
NOTE:
The control circuit for the EVAP vent solenoid valve is pulled-up to voltage within the ECM, 2.6-4.6 volts on the control circuit is normal.