Circuit/System Testing

Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, open and close drivers door, disconnect the harness connector at the B10B Ambient Light/Sunload Sensor. It may take up to 10 min for all vehicle systems to power down.
Test for less than 10 Ω between the low reference circuit terminal 6 and ground.
- If 10 Ω or greater
1. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC Control Module.
2. Test for less than 2 Ω in the low reference circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the K33 HVAC Control Module.
- Go to next step: If less than 10 Ω
Ignition ON.
Verify the scan tool Ambient Light Sensor parameter is greater than 4.65 V.
- If 4.65 V or less
1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the signal circuit terminal 5 and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, replace the K9 Body Control Module.
- Go to next step: If greater than 4.65 V
Install a 3 A fused jumper wire between the signal circuit terminal 5 and the low reference circuit terminal 6.
Verify the scan tool Ambient Light Sensor parameter is less than 0.196 V.
- If 0.196 V or greater
1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit terminal 5 and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - If less than 1 V
3. Test for less than 2 Ω in the signal 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.
- Go to next step: If less than 0.196 V
Test or replace the B10B Ambient Light/Sunload Sensor.