Testing the Serial Data Circuits for an Open/High Resistance (Data Bus Diagnostic Tool)
WARNING: This page is about a different car, the 2016 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition/Vehicle OFF, all access doors closed, all vehicle systems OFF and all keys at least 3 m (9.8 ft) away from vehicle. It may take up to 10 min for all vehicle systems to power down.
- Disconnect the harness connectors with the high speed GMLAN serial data circuits at the non responding device closest to the responding device.
- Disconnect the harness connectors with the high speed GMLAN serial data circuits at the responding device closest to the non responding device.
- Test for less than 2 Ω in each of the high speed GMLAN serial data circuits end to end between the two devices that was just disconnected.
- If 2 Ω or greater
Repair the open/high resistance in the serial data circuit.
- If less than 2 Ω
- If 2 Ω or greater
- Replace the non responding device that was disconnected.