Circuit/System Testing

Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B55 Hood Ajar Switch. 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 3 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.
Test for greater than 10 V between the signal circuit terminal 2 and ground.
- If 10 V or less
1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the signal circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - Go to next step: If Infinite resistance.
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 greater than 10 V
Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON.
Test for less than 1 V between the signal circuit terminal 2 and ground.
- If 1 V or greater
  Repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
Test or replace the B55 Hood Ajar Switch.