Circuit/System Testing

NOTE:

Each lighting component may need to be disconnected to isolate a short to ground. Use the schematics to identify the following:

Lighting components the vehicle is equipped with
Each component's control and ground circuit terminals
Component locations on the lighting control circuit

Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, open and close drivers door, disconnect the harness connector at the inoperative courtesy lamp. It may take up to 2 min for all vehicle systems to power down.
Test for less than 10 Ω between the appropriate ground circuit terminal listed below and ground.
- A3L Sunshade - Left terminal B
- A3R Sunshade - Right terminal B
- A98 Front Overhead Console Assembly terminal 5
- E27 Instrument Panel Compartment Lamp terminal 2
- E37M Dome/Reading Lamps - Middle terminal 3
- E37R Dome/Reading Lamps - Rear terminal 3
- If 10 Ω or greater
1. Ignition OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, repair the open/high resistance in the ground connection.
- Go to next step: If less than 10 Ω
Connect a test lamp between the appropriate control circuit terminal listed below and ground, ignition ON.
- A3L Sunshade - Left terminal A
- A3R Sunshade - Right terminal A
- A98 Front Overhead Console Assembly terminal 7
- E27 Instrument Panel Compartment Lamp terminal 1
- E37M Dome/Reading Lamps - Middle terminal 4
- E37R Dome/Reading Lamps - Rear terminal 4
Verify the test lamp turns ON and OFF when commanding the Inadvertent Load ON and OFF with a scan tool.
- If the test lamp is always OFF
1. Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the control 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 control circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the K9 Body Control Module.
- If the test lamp is always ON
1. Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the control circuit terminal 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 the test lamp turns ON and OFF
Test or replace the courtesy lamp.