Circuit/System Testing
- Ignition OFF, disconnect the automatic level control (ALC) compressor exhaust solenoid.
- Ignition ON, verify that a test lamp does not illuminate between the solenoid control circuit terminal C at the connector and ground.
- If the test lamp illuminates, test the control circuit for a short to voltage.
- Verify that a test lamp illuminates between the B+ circuit terminal B and ground.
- If the test lamp does not illuminate, test the B+ circuits for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the ALC compressor.
- Connect a test lamp between the B+ circuit terminal B and the control circuit terminal C.
- With a scan tool, clear all ALC DTCs.
- Command the exhaust solenoid ON and OFF. The test lamp should turn ON and OFF when changing between the commanded states.
- If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ESCM.
- If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ESCM.
- If all circuits test normal, test or replace the ALC compressor.