Circuit/System Testing

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

Test for less than 1.0 ohm between the ground circuit terminal 5 of the DLC and ground.
- If greater than the specified range, test the ground circuit for open/high resistance.
Ignition OFF, disconnect the harness connector at JX 205.
Ignition ON, test for less than 1 volt between the serial data circuit terminal 1 of the DLC and ground.
- If greater than the specified range, test the serial data circuit for a short to voltage.
Test for infinite resistance between the serial data circuit terminal 1 of the DLC and ground.
- If less than the specified value, test the serial data circuit for a short to ground.
Test for less than 2 ohms on the serial data circuit between terminal 1 of the DLC and terminal 1 of JX 205.
- If greater that the specified range, test the serial data circuit for an open/high resistance.
Install a 3-amp fused jumper wire between terminal 1 and terminal 2 of JX 205. Attempt to communicate with the remote control door lock receiver (RCDLR). Communication should be available.
- If communication is not available refer to JX 405 Circuit Test .
Install another 3-amp fused jumper wire to terminal 1 of JX 205.

IMPORTANT: Allow communications for 5 seconds after connecting a module with the jumper to determine if communication is interrupted or not.

With RCDLR communications established, use the other end of the jumper wire to connect all other terminals of JX 205, harness side, one at a time and verify that low speed communication remains available to the RCDLR.
- If communication is interrupted after connecting an individual module at JX 205, test the serial data circuit between JX 205 and the last module connected for a short to voltage or short to ground. If the circuit tests normal, replace the module that caused no communication.