Circuit/System Testing

Rear Object Sensor Malfunction

1. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Disconnect the harness connector at the appropriate B78 Rear Object Sensor.
2. Test for less than 10 Ω between the low reference circuit terminal 2 and ground.
   • If 10 Ω or greater 
   1. Vehicle OFF, disconnect the harness connector at the K41R Rear Parking Assist 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 K41R Rear Parking Assist Control Module.
   • If less than 10 Ω 
3. Vehicle ON.
4. Test for 7.5-9.5 V between the 8 V reference circuit terminal 1 and ground.
   • If less than 7.5 V 
   1. Vehicle OFF, disconnect the harness connector at the K41R Rear Parking Assist Control Module.
   2. Test for infinite resistance between the 8 V reference 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 8 V 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 K41R Rear Parking Assist Control Module.
   • If greater than 9.5 V 
   1. Vehicle OFF, disconnect the harness connector at the K41R Rear Parking Assist Control Module, vehicle ON.
   2. Test for less than 1 V between the 8 V reference circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K41R Rear Parking Assist Control Module.
   • If between 7.5-9.5 V 
5. Replace the appropriate B78 Rear Object Sensor.

Rear Parking Assist Control Module/Speaker Malfunction

1. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Disconnect the harness connector at the K41R Rear Parking Assist Control Module.
2. Test for less than 10 Ω between the ground circuit terminal 9 and ground.
   • If 10 Ω or greater 
   1. Vehicle OFF, disconnect the harness connector at the K41R Rear Parking Assist 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 K41R Rear Parking Assist Control Module.
   • If less than 10 Ω 
3. Vehicle ON.
4. Verify a test lamp illuminates between the ignition circuit terminal 1 and ground.
   • If the test lamp does not illuminate and the circuit fuse is good 
   1. Vehicle 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.
   • If the test lamp does not illuminate and the circuit fuse is open 
   1. Vehicle 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 K41R Rear Parking Assist Control Module.
   • If the test lamp illuminates 
5. Vehicle ON, park brake applied, transmission in REVERSE.
6. Verify a test lamp illuminates between the control circuit terminal 4 and ground.
   • If the test lamp does not illuminate 
   1. Vehicle 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 the test lamp illuminates 
7. Vehicle OFF, disconnect the harness connector at the P28 Speaker - Parking Assist.
8. Test for less than 10 Ω between the low reference circuit terminal 1 and ground.
   • If 10 Ω or greater 
   1. Vehicle OFF, disconnect the harness connector at the K41R Rear Parking Assist 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 K41R Rear Parking Assist Control Module.
   • If less than 10 Ω 
9. Ignition ON.
10. 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.
    • 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 K41R Rear Parking Assist Control Module.
11. Vehicle OFF. Place an object less than 0.4m away from the rear bumper. Connect a test lamp between reference voltage terminal 1 and control circuit terminal 2.
12. Verify the test lamp illuminates when the vehicle is started and the transmission is shifted into reverse.
    • If the test lamp does not illuminate 
    1. Vehicle OFF.
    2. 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 K41R Rear Parking Assist Control Module.
    • If the test lamp illuminates 
13. Test or replace the P28 Speaker - Parking Assist.