Circuit/System Testing
- Vehicle OFF, disconnect the harness connector at the K20 steering wheel control switch-left.
- Vehicle in Service Mode, test for B+ between the voltage reference circuit and ground.
- If less than the specified value, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
- Test for B+ between the voltage reference circuit and the signal circuit.
- If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
- Vehicle OFF, disconnect the X3 harness connector at the K9 BCM.
- Test for infinite resistance between the signal circuit terminal 9 and ground.
- If less than the specified value, test the signal circuit for a short to ground.
- If all circuits test normal, test or replace the K20 steering wheel control switch-left.