Circuit/System Testing
WARNING: This page is about a different car, the 2007 Suzuki XL7. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector C2 ground circuit terminal at the HVAC control module.
- Ignition OFF, test for less than 1.0 Ω of resistance between the ground circuit terminal and ground.
- If greater than 1.0 Ω, test the ground circuit for an open/high resistance.
- Install a 3-amp fused jumper wire between the a/c request signal circuit terminal and ground. With a scan tool, verify the A/C Request Switch parameter is ON.
- If not On, test the a/c request signal circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the BCM.
- Reconnect the harness connector of the HVAC control module. With a scan tool, verify the A/C Request Switch parameter cycles between On and Off with each press of the A/C switch.
- If the parameter does not cycle, test the signal circuit for a short to ground. If the circuit tests normal, test or replace the HVAC control module.
- Remove the A/C compressor clutch relay.
- Verify that a test lamp illuminates between the relay coil B+ circuit and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
- Verify that a test lamp illuminates between the relay switch B+ circuit and ground.
- If the test lamp does not illuminate, test the relay switch B+ circuit for an open/high resistance. If the A/C fuse is open, test the relay switch control circuit for a short to ground. If all circuits test normal, test or replace the A/C compressor clutch.
- Disconnect the harness connector at the A/C compressor clutch.
- Ignition OFF test for less than 1.0 Ω of resistance between the A/C compressor ground circuit and ground.
- If greater than 1.0 Ω, test the ground circuit for an open/high resistance.
- Connect the harness connector at the A/C compressor clutch.
- Connect a 10-amp fused jumper wire between the relay switch B+ circuit and the relay switch control circuit. Verify the A/C compressor clutch engages.
- If the A/C compressor clutch does not activate, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the A/C compressor.
- Connect a test lamp between the relay control circuit and the relay coil B+ circuit.
- Using a scan tool, command the A/C relay output ON and OFF. The test lamp should turn ON and OFF when changing between the commanded states.
- If the test lamp remains ON all the time, test for a short to ground on the control circuit. If the circuit tests normal, replace the ECM.
- If the test lamp remains OFF all the time, test for a short to voltage or an open/high resistance on the control circuit. If the circuit tests normal, replace the ECM.
- If all circuits test normal, test or replace the A/C compressor.