Circuit/System Verification
- Ignition ON/Vehicle In Service Mode.
- Attempt to communicate with all devices on the chassis high speed GMLAN serial data circuit. Refer to Data Link References to determine how many devices should be communicating on this bus.
- Verify that all chassis high speed GMLAN devices are communicating.
- If only one device is not communicating
Refer to Circuit/System Testing - Testing the Device Circuits.
- If two or more devices are not communicating
Refer to Circuit/System Testing - Serial Data Starting Point.
- Go to next step: If all devices are communicating
- If only one device is not communicating
- All OK.