Circuit/System Testing

Ignition ON, observe the DTC information with a scan tool. Verify that DTC P2420 is not set.
- If the DTC is set, refer to DTC P2419 or P2420 .
Ignition OFF, disconnect the harness connector at the EVAP purge solenoid.
Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit terminal 2 and ground.
- If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary.
Ignition OFF, connect a test lamp between the control circuit terminal 1 and the ignition 1 voltage circuit terminal 2.
Ignition ON, command the EVAP purge solenoid ON and OFF with a scan tool. The test lamp should be pulsing ON and OFF when activated.
- If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the PCM.
- If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the PCM.
Connect a vacuum gauge to the purge port of the EVAP purge solenoid.
Engine running, verify the vacuum gauge reading is zero.
- If the vacuum pressure is greater than the specified range, replace the EVAP purge solenoid valve.
Command the EVAP purge solenoid ON with the scan tool. Verify the vacuum gauge reads manifold vacuum when the solenoid is activated.
- If the vacuum pressure is less than the specified range, replace the EVAP purge solenoid valve.
If all circuits test normal, test for the following conditions:
- DTC P0455 was also set-Refer to DTC P0455 or P0456 .
- A blockage or restriction in the purge line between the purge solenoid and the EVAP canister
- A faulty EVAP canister-Refer to Evaporative Emission Control System Diagnosis .