Circuit/System Testing

WARNING: This page is about a different car, the 2018 GMC Canyon and 2018 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.

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.
- Go to next step: If less than 10 Ω
Ignition ON.
Verify a test lamp illuminates between the ignition circuit terminal 3 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.
- Go to next step: If the test lamp illuminates
Engine running, parking brake applied, transmission in REVERSE.
Verify a test lamp illuminates between the control circuit terminal 1 and ground.
- If the test lamp does not illuminate
1. Ignition OFF, disconnect the X1 harness connector at the X51A Fuse Block - Instrument Panel
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 (Automatic Transmission)Backup Lamps Malfunction (Manual Transmission) .
- Go to next step: If the test lamp illuminates
Ignition OFF, disconnect the X1 harness connector at the A11 Radio, ignition ON.
Test for less than 1 V between the signal circuit terminals listed below and ground:
- A11 Radio signal (+) circuit terminal 15 X1
- A11 Radio signal (-) circuit terminal 14 X2
- If 1 V or greater
  Repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
Test for infinite resistance between the signal circuit terminals listed below and ground:
- A11 Radio signal (+) circuit terminal 15 X1
- A11 Radio signal (-) circuit terminal 14 X2
- If less than infinite resistance
  Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
Test for less than 2 Ω between the A11 Radio signal (+) circuit terminal 15 X1 and the B87 Rearview Camera signal (+) circuit terminal 2.
- If 2 Ω or greater
  Repair the open/high resistance in the circuit.
- Go to next step: If less than 2 Ω
Test for less than 2 Ω between the A11 Radio signal (+) circuit terminal 14 X1 and the B87 Rearview Camera signal (+) circuit terminal 6.
- If 2 Ω or greater
  Test the signal circuit for an open/high resistance.
- Go to next step: If less than 2 Ω
Add Nyogel lubricant 760G to electrical terminals.
Reconnect all electrical connections.
Engine running, parking brake applied, transmission in REVERSE.
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, parking brake applied, transmission in REVERSE.
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 A11 Radio.
  - Go to next step: If a clear rear vision image is displayed
4. All OK.
- If a blank black screen is displayed
  Replace the A11 Radio.
- Go to next step: If a clear rear vision image is displayed
All OK.