Circuit/System Testing
WARNING: This page is about a different car, the 2007 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the automatic level control (ALC) compressor.
- Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal A 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 C and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ELC MDL fuse is open, test the control circuit for a short to ground. If the circuit tests normal, test or replace the automatic level control (ALC) compressor assembly.
- Connect a test lamp between the B+ circuit terminal C and the control circuit terminal A.
- Command the exhaust solenoid ON and OFF with a scan tool. 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 ESC module.
- 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 ESC module.