Circuit/System Testing
WARNING: This page is about a different car, the 2008 Cadillac XLR. However, it is still accessible from the selected car via links, so may be relevant.
- Disconnect the harness connector X1 at the turn signal / multifunction switch.
- Ignition ON, test for greater than 10 volts between the supply voltage circuit terminal 1 and ground.
- If less than the specified range, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
- Verify the scan tool Cruise Control Switch parameter is OFF.
- If not the specified value, test the signal circuit terminal 5 for a short to voltage. If the circuit tests normal, replace the BCM.
- Ignition OFF, connect the harness connector at the turn signal/multifunction switch.
- Ignition ON, with the cruise control switch in the ON position, observe the scan tool Cruise Control Switch parameter. The parameter should display ON.
- If not the specified value, test the signal circuit terminal 5 for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the turn signal / multifunction switch.
- Observe the scan tool Cruise Control Switch parameter while pressing the RES + portion of the cruise control switch. The parameter should display Resume.
- If not the specified value, test or replace the turn signal / multifunction switch.
- Observe the scan tool Cruise Control Switch parameter while pressing the SET - portion of the cruise control switch. The parameter should display Set.
- If not the specified value, test or replace the turn signal / multifunction switch.
- Observe the scan tool Cruise Cancel switch parameter. The parameter should display Inactive.
- If not the specified value, test or replace the steering wheel controls switch - left.
- If the circuits test normal, test or replace the ECM.