Circuit/System Testing

Vehicle OFF and all vehicle systems OFF, disconnect the harness connector at the B55 Engine Compartment Cover Switch.
Verify a test lamp illuminates between ground circuit terminal 3 and B+.
- If the test lamp does not illuminate
1. Repair the open/high resistance on circuit 150 or the ground connection.
- Go to next step: If the test lamp illuminates
Ignition ON, Vehicle in Service Mode.
Test for 4.8 - 5.2V between the signal circuit terminal 1 and ground.
- If less than 4.8V
1. Ignition/Vehicle - Off.
2. Disconnect the electrical connector: X1 at the K20 Engine Control Module.
3. Test circuit 4063 for a short to ground.
  - If a short to ground is found, repair the fault on the circuit.
  - Go to next step: If a short to ground is not found
4. Test circuit 4063 for an open/high resistance.
  - If an open/high resistance is found, repair the fault on the circuit.
  - Go to next step: If an open/high resistance is not found.
5. Replace the K20 Engine Control Module.
- If greater than 5.2V
1. Ignition/Vehicle - Off.
2. Disconnect the electrical connector: X1 at the K20 Engine Control Module.
3. Ignition ON, Vehicle in Service Mode.
4. Test circuit 4063 for a short to voltage.
  - If a short to voltage is found, repair the fault on the circuit.
  - Go to next step: If a short to voltage is not found.
5. Replace the K20 Engine Control Module.
- Go to next step: If between 4.8 - 5.2V
Test or replace the B55 Engine Compartment Cover Switch.