Circuit/System Testing
WARNING: This page is about a different car, the 2007 GMC Sierra, 2007 GMC Cab & Chassis Sierra, 2007 Chevrolet Silverado, and 2007 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.