Circuit/System Testing

WARNING: This page is about a different car, the 2015 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Circuit/System Verification must be performed before Circuit/System Testing.
Under normal operating conditions the Human Interface Machine Control Module will become very hot. The module should be allowed to cool down prior to removal for any service procedure.

Ignition OFF, disconnect the harness connector at the B87 Rearview Camera.
Test for less than 10 Ω between the ground circuit terminal 5 and ground.
- 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.
- If less than 10 Ω
Ignition ON.
Verify a test lamp illuminates between the ignition circuit terminal 6 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. 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, verify the fuse is OK and there is voltage at the fuse. Refer to Power Mode Mismatch .
- If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the ignition circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, replace the B87 Rearview Camera.
- If the test lamp illuminates
Engine running, park brake applied, transmission in R.
Test for greater than 11 V between the control circuit terminal 3 and ground.
- If less than 11 V
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.
  - 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 greater than 11 V
Ignition OFF, disconnect the X2 harness connector at the K74 Human Interface Control Module, ignition ON.
Test for less than 1 V between the signal circuit terminal listed below and ground:
- B87 Rearview Camera signal (+) circuit terminal 1
- B87 Rearview Camera signal (-) circuit terminal 4
- If 1 V or greater
  Repair the short to voltage on the circuit.
- If less than 1 V
Test for infinite resistance between the signal circuit terminal listed below and ground:
- B87 Rearview Camera signal (+) circuit terminal 1
- B87 Rearview Camera signal (-) circuit terminal 4
- If less than infinite resistance
  Repair the short to ground on the circuit.
- If infinite resistance
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
Test for less than 2 Ω in the signal (-) circuit end to end.
- If 2 Ω or greater
  Test the signal circuit for an open/high resistance.
- If less than 2 Ω
Replace the B87 Rearview Camera.
Engine running, transmission in R, verify a clear rear vision image is displayed on the P17 Info Display Module.
- If a clear rear vision image is not displayed
  Replace the K74 Human Interface Control Module.
- If a clear rear vision image is displayed
All OK.