Circuit/System Testing

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

Ignition/Vehicle & All vehicle systems - Off
Disconnect the electrical connector:X1 @ K20 Engine Control Module
Connect a test lamp between the test points:
- {LFV} Signal circuit terminal 6 & Ground
- {-LFV} Signal circuit terminal 50 & Ground
Ignition - On / Vehicle - In Service Mode
Brake Applied & Brake Pedal Not Applied
Verify the test lamp turns On and Off.
- If the test lamp is always Off
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Disconnect the electrical connector:X5 @ K9 Body Control Module
3. Test for infinite resistance between the test points:Signal circuit terminal 12 @ K9 Body Control Module & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
4. Test for less than 2 ohms between the test points:Signal circuit terminal 12 @ K9 Body Control Module & 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
1. Ignition/Vehicle & All vehicle systems - Off
2. Disconnect the electrical connector.X5 @ K9 Body Control Module
3. Ignition - On / Vehicle - In Service Mode
4. Test for less than 1 V between the test points:Signal circuit terminal 12 @ K9 Body Control Module & 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