Circuit/System Testing

Park Lamp Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the headlamp and panel dimmer switch.
2. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal 8.
   • If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Park Lamp Switch parameter is Inactive.
   • If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3 A fused jumper wire between the signal circuit terminal 2 and ground. Verify the scan tool Park Lamp Switch parameter is Active.
   • If not the specified value, test the signal circuit for a short to voltage or open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the headlamp and panel dimmer switch.

Park, License, and/or Tail Lamps Malfunction

1. Ignition OFF, disconnect the park lamp relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.
   • If the test lamp illuminates, test the control circuit for a short to voltage.
3. Verify that a test lamp illuminates between the B+ circuit terminal 86 and ground.
   • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the control circuit terminal 87 for a short to ground. If the circuit tests normal, test or replace the park lamp relay.
4. Verify that a test lamp illuminates between the B+ circuit terminal 30 and ground.
   • If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.
5. Disconnect the harness connector at the appropriate park/license/marker lamp.
6. Ignition OFF, exterior lamps OFF, test for less than 5 Ω between the appropriate ground circuit terminal listed below and ground.
   • Park/Turn Signal Lamp - Left or Right front terminal C - with X88
   • Park/Turn Signal Lamp - Left or Right front terminal G - with Z88
   • Marker Lamp - Left or Right front terminal A - with Z75
   • Marker Lamp - Left or Right front terminal B - with Z88 or X88
   • Park Lamp - Left or Right front terminal B - Z75
   • Tail/Stop and Turn Signal Lamp - Upper Left or Right rear terminal GND - with X88 - E52
   • Tail/Turn Signal Lamp - Left or Right terminal GND - with X88 + E52
   • Tail/Stop Lamp - Left or Right Rear terminal GND - w/o X88 + E52
   • Tail/Stop Lamp - Left terminal C X411 - Z88 with E52
   • Tail/Stop Lamp - Left terminal B X411 - Z88 without E52
   • Tail/Stop Lamp - Right terminal C X412 - Z88 with E52
   • Tail/Stop Lamp - Right terminal B X412 - Z88 without E52
   • Marker Lamp - Left or Right Rear terminal B - with Z88
   • Marker Lamp - Left or Right Rear terminal A - with Z75 or X88 - E52
   • Tail Lamp Circuit Board - Left or Right Rear terminal D - with Z75 + E52
   • License lamp terminal B
   • If greater than the specified range, test the ground circuit for an open/high resistance.
7. Connect the harness connector at the park/license/marker lamp.
8. Connect a 15 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the park/marker lamps illuminate.
   • If the park/marker lamps do not illuminate, test the control circuit for an open/high resistance. If the circuit tests normal, replace the inoperative park/license/marker lamp.
9. Connect a test lamp between the control circuit terminal 85 and B+ circuit terminal 86.
10. Command the Parking Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
    • If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
    • If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
11. If all circuits test normal, test or replace the park lamp relay.