Testing the Serial Data Circuits for a Short between the Circuits
WARNING: This page is about a different car, the 2010 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connectors with the mid speed or chassis high speed serial data circuits at an easily accessible control module, that is not communicating.
- Ignition OFF for 60 seconds, test for less than 110 Ω between each pair of serial data circuits. Verify that one pair of serial data circuits are less than 110 Ω.
- If greater than the specified range for each pair of serial data circuits, replace the control module that was disconnected.
- Connect the harness connectors at the control module that was disconnected.
- Disconnect the harness connectors with the mid speed or chassis high speed serial data circuits at another control module, in the direction of the circuits shorted together.
- Ignition OFF for 60 seconds, test for less than 110 Ω between each pair of serial data circuits. Verify that one pair of serial data circuits are less than 110 Ω.
- If between the specified range for each pair of serial data circuits, replace the control module that was just disconnected.
- Repeat step 3 until one of the following conditions are isolated:
- Serial data circuits shorted together between 2 control modules
- Serial data circuits shorted together between a control module and a terminating resistor
- A shorted terminating resistor