Circuit/System Testing

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Using the DTC Descriptor and Diagnostic Aids, determine which module is not communicating.
Ignition OFF, disconnect the harness connector at the module that is not communicating.
Test for less than 0.5 ohm of resistance between each ground circuit of the module that is not communicating and ground.
- If greater than 0.5 ohm, repair the open/high resistance in the ground circuit.
Test for battery voltage between each battery positive voltage circuit of the module that is not communicating and ground.
- If less than battery voltage, repair the short to ground or open/high resistance in the battery positive voltage circuit.
Ignition ON, test for battery voltage between each ignition circuit of the module that is not communicating and ground.
- If less than battery voltage, repair the short to ground or open/high resistance in the ignition circuit.
Ignition OFF, disconnect the harness connector at the module that reported the no communication DTC.
Ignition OFF, test for less than 0.5 ohm of resistance in each serial data circuit between the module that is not communicating and the module that reported the DTC.
- If greater than 0.5 ohm, repair the open/high resistance in the serial data circuit.
If all tests normal, replace the module that is not communicating.