Circuit/System Testing

Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B87 Rearview Camera. It may take up to 2 min for all vehicle systems to power down.
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 (Without HP9) and/or Power Mode Mismatch (With HP9) .
- 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.
Verify a test lamp illuminates between the control circuit terminal 3 and ground.
- If the test lamp does not illuminate
1. Ignition OFF, disconnect the X4 harness connector at the X50A Fuse Block - Underhood
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, refer to Backup Lamps Malfunction .
- If the test lamp illuminates
Ignition OFF, disconnect the X2 harness connector at the K74 Human Machine Interface Control Module, ignition ON.
Test for less than 1 V between the signal circuit terminals listed below and ground:
- K74 Human Machine Interface Control Module signal (+) circuit terminal 5 X2
- K74 Human Machine Interface Control Module signal (-) circuit terminal 6 X2
- 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 terminals listed below and ground:
- K74 Human Machine Interface Control Module signal (+) circuit terminal 5 X2
- K74 Human Machine Interface Control Module signal (-) circuit terminal 6 X2
- If less than infinite resistance
  Repair the short to ground on the circuit.
- If infinite resistance
Test for less than 2 Ω; between the K74 Human Machine Interface Control Module signal (+) circuit terminal 5 X2 and the B87 Rearview Camera signal (+) circuit terminal 1.
- If 2 Ω or greater
  Repair the open/high resistance in the circuit.
- If less than 2 Ω
Test for less than 2 Ω between the K74 Human Machine Interface Control Module signal (+) circuit terminal 6 X2 and the B87 Rearview Camera signal (+) circuit terminal 4.
- If 2 Ω or greater
  Test the signal circuit for an open/high resistance.
- If less than 2 Ω
Add Nyogel lubricant 760G to electrical terminals.
Reconnect all electrical connections.
Engine running, park brake applied, transmission in R.
Verify a clear rear vision image is displayed on the P17 Info Display Module.
- If a blank blue screen or distorted image is displayed
1. Replace the B87 Rearview Camera.
2. Engine running, transmission in R,
3. 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 Machine Interface Control Module.
  - If a clear rear vision image is displayed
4. All OK.
- If a blank black screen is displayed
  Replace the K74 Human Machine Interface Control Module.
- If a clear rear vision image is displayed
All OK.