Circuit/System Testing
WARNING: This page is about a different car, the 2020 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
- Use the Wiring Schematics to identify the items/configurations listed below:
- Brake Pedal Position Sensor Signal @ K20 Engine Control Module
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the component:K20 Engine Control Module
- Ignition - On / Vehicle - In Service Mode
- Connect a test lamp between the test points:Brake Pedal Position Sensor Signal & Ground
- Slowly press and release the brake pedal.
Verify the test lamp turns On and Off.
- If the test lamp is always Off
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the component:K9 Body Control Module
- {If equipped}Disconnect all components on the circuit:Brake Pedal Position Sensor Signal
- Test for infinite resistance between the test points:Signal circuit terminal 12 @ K9 Body Control ModuleX5 & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- Test for less than 2 ohms between the test points:Signal circuit terminal 12 @ K9 Body Control ModuleX5 & The other end of the circuit
- If 2 ohms or greater - Repair the open/high resistance in the circuit.
- If less than 2 ohms - Replace the component:K9 Body Control Module
- If the test lamp is always On
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the component:K9 Body Control Module
- Ignition - On / Vehicle - In Service Mode
- Test for less than 1 V between the test points:Signal circuit terminal 12 @ K9 Body Control ModuleX5 & Ground
- If 1 V or greater - Repair the short to voltage on the circuit.
- If less than 1 V - Replace the component:K9 Body Control Module
- Go to next step: If the test lamp turns On and Off
- Replace the component:K20 Engine Control Module