Circuit/System Testing: Notes
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
High Speed GMLAN Initial Test
- Ignition OFF, test for less than 1.0 ohm of resistance between the data link connector (DLC) ground circuit terminal 5 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Disconnect the X1 harness connector at the transfer case control module (TCC).
- Ignition ON, attempt to communicate with the vehicle control interface module (VCIM).
- If communication is established refer to DIAGNOSTIC 2 .
- If communication is not established, refer to DIAGNOSTIC 1 .