Testing the Serial Data Circuits for a Short to Ground
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connectors at the JX 221, JX 339, and JX 223 splice packs, as equipped.
- Test for infinite resistance between the DLC serial data circuit terminal 1 and ground.
- If not the specified value, repair the short to ground.
- Ignition OFF for 60 seconds, test for greater than 100 Ω between each serial data circuit and ground.
- If less than the specified range, perform the appropriate test listed below:
- Serial data circuits with one control module, test the serial data circuit for a short to ground. If the circuit tests normal replace the control module.
- Serial data circuits with 2 or more control modules, test each section of the serial data circuit for a short to ground. If the circuits test normal, replace the control module that causes the short to ground when connected.