Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.
The High Voltage Disabling procedure will perform the following tasks:
Failure to follow the procedures exactly as written may result in serious injury or death.
The High Voltage Disabling procedure will perform the following tasks:
- Identify how to disable high voltage.
- Identify how to test for the presence of high voltage.
- Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.
Failure to follow the procedures exactly as written may result in serious injury or death.
- Ignition OFF, disconnect harness connector X2 of the SDGM.
- Ignition ON, verify that a test lamp illuminates between the wake up signal circuit terminal 19 and ground.
- If the test lamp does not illuminate, test the circuit for an open/high resistance.
- Ignition OFF, connect the harness connector of the SDGM.
- Perform the High Voltage Disabling procedure.
- Ignition OFF, disconnect harness connector X1 of the BECM.
- Reconnect the 12-volt battery.
- Ignition ON, verify that a test lamp illuminates between the wake up signal circuit terminal 12 and ground.
- If the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuit tests normal, replace the SDGM.
- If all circuits test normal, replace the BECM.