Circuit/System Testing

WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, and all vehicle systems OFF, disconnect the appropriate harness connector at the control module setting the DTC.
Test for less than 1 V between the ignition circuit terminal and ground.
- If 1 V or greater
  Repair the short to voltage on the circuit.
- If less than 1 V
Ignition ON.
Verify a test lamp illuminates between the ignition circuit terminal and ground.
- If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF remove the test lamp.
2. Test for less than 2 Ω in the ignition circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, refer to Power Mode Mismatch (Without KL9) Power Mode Mismatch (With KL9) .
- If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF remove the test lamp
2. Test for infinite resistance between the ignition circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
- If the test lamp illuminates
Replace the control module setting the DTC.