Circuit/System Testing
WARNING: This page is about a different car, the 2008 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
- Disconnect the harness connector X2 at the 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.
- Ignition ON, test for 0.0 volts between the cruise control switch signal circuit and ground.
- If greater than the specified value, test the signal circuit terminal 5 for a short to voltage. If the circuit tests normal, replace the IPM.
- Ignition OFF, connect the harness connector X2 at the multifunction switch.
- Ignition ON, with the cruise control switch in the ON position, observe the scan tool Cruise parameter. The parameter should display 29 Counts.
- 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 multifunction switch.
- Observe the scan tool Cruise parameter while pressing the RES + portion of the cruise control switch. The parameter should display 76 Counts.
- If not the specified value, test or replace the multifunction switch.
- Observe the scan tool Cruise parameter while pressing the SET - portion of the cruise control switch. The parameter should display 148 Counts.
- If not the specified value, test or replace multifunction switch.
- Observe the Cruise Cancel Switch parameter. The parameter should display Inactive.
- If not the specified value, test or replace the steering wheel controls - left.
- If the circuits test normal, test or replace the ECM.