Circuit/System Testing

NOTE:

An open ignition circuit or fuse before the control module will cause communication DTCs or power mode mismatch DTCs to set against or in the control module. This failure mode will be diagnosed in the no communications diagnostic procedure or power mode mismatch.
This test assumes the ignition circuit has a driver that will open under a high current condition before the fuse opens.
The driver can open under normal conditions such as battery run down protection or a retained accessory power mode.

Verify the cruise control buttons operated normally.
- If the cruise control buttons do not operate normally
  Refer to: Cruise Control Malfunction
- Go to next step: If the cruise control buttons operate normally
Ignition OFF, disconnect the harness connector at the S70C Steering Wheel Controls Switch - Left Upper, ignition ON.
Verify a test lamp illuminates between the ignition circuit terminal 6 and ground.
- If the test lamp does not illuminate
1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the ignition circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
3. 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, test or replace the K9 Body Control Module.
- Go to next step: If the test lamp illuminates
Test for less than 1 V between the signal circuit terminal 4.
- If 1 V or greater
1. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - If less than 1 V, replace the K9 Body Control Module.
- Go to next step: If less than 1 V
Ignition OFF, disconnect the harness connector at the S70A Steering Wheel Controls Switch - Left Lower
Test for less than 2 ohms between the test points: S70A Steering Wheel Controls Switch - Left Lower terminal 3 & S70C Steering Wheel Controls Switch - Left Upper terminal 5
- If greater than 2 ohms - Replace the component: Steering wheel harness
- Go to next step: If less than 2 Ω
Test for less than 2 ohms between the test points: S70A Steering Wheel Controls Switch - Left Lower terminal 2 & S70C Steering Wheel Controls Switch - Left Upper terminal 4
- If greater than 2 ohms - Replace the component: Steering wheel harness
- Go to next step: If less than 2 Ω
Test or replace the S70A Steering Wheel Controls Switch - Left Lower.