Circuit/System Testing

Courtesy Lamp Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate lamp.
2. Test for less than 5.0 Ω between the ground circuit terminal B and ground.
   • If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the control circuit terminal listed below and the ground.
   • Courtesy/Reading Lamp terminal A
   • Dome/Reading Lamp terminal C
   • Door Courtesy Lamp terminal A
   • Sunshade Lamps terminal A
   • Dome Lamp terminal A
   • Cargo Lamp terminal A
4. Ignition ON, command the Courtesy Lamps output control ON and OFF with the scan tool. The test lamp should turn ON and OFF.
   • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
   • If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the courtesy lamp.

Dome/Interior Lamp Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the headlamp and panel dimmer switch.
2. Test for less than 5.0 Ω between the ground circuit terminal 8 and ground.
   • If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Ctsy. Lamp Actv. Reason parameter is Off.
   • If the parameter is Manual or Manual Defeat, test the appropriate signal circuit terminal for a short to ground. If the circuit tests normal, replace the BCM.
   • Manual terminal 12
   • Manual Defeat terminal 9
4. Install a 3 A fused jumper wire between the signal circuit terminal 12 and the ground circuit terminal 8. Verify the scan tool Ctsy. Lamp Actv. Reason parameter is Manual.
   • If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
5. Install a 3 A fused jumper wire between the signal circuit terminal 9 and the ground circuit terminal 8. Verify the scan tool Ctsy. Lamp Actv. Reason parameter is Manual Defeat.
   • If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
6. If all circuits test normal, test or replace the headlamp and panel dimmer switch.

Reading Lamps Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the BCM.
2. Verify a test lamp illuminates between the IS LPS fuse B+ circuit terminal 2 and ground.
   • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
3. Reconnect the X3 harness connector at the BCM.
4. Disconnect the harness connector at the inoperative courtesy/reading lamp assembly.
5. Scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5.0 Ω between the ground circuit terminal B and ground.
6. Verify a test lamp illuminates between the control circuit terminal listed below and ground:
   • Courtesy/Reading Lamp terminal C
   • Dome/Reading Lamp terminal A
   • If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
7. Remove the IS LPS fuse and verify the test lamp turns OFF.
   • If the test lamp remains illuminated, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
8. If all circuits test normal, replace the courtesy lamp assembly.

Vanity Mirror Lighting Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate vanity mirror lamp.
2. Test for less than 5.0 Ω between the ground circuit terminal B and ground.
   • If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the control circuit terminal A and ground.
   • If the test lamp does not illuminate, test the inadvertent power supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
4. Connect the harness connector at the vanity mirror lamp.
5. Remove the IS LPS fuse and verify the test lamp turns OFF.
   • If the test lamp remains illuminated, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
6. If all circuits test normal, replace the vanity mirror.

Outside Rearview Mirror Illumination Malfunction

1. Disconnect the harness connector at the appropriate exterior illumination lamp.
2. Ignition ON, verify that a test lamp illuminates between the exterior illumination lamp supply circuit terminal and ground.
   • If the test lamp does not illuminate, test the exterior illumination lamp supply circuit for a short to ground or an open/high resistance.
3. Connect a test lamp between the low side control circuit terminal and the exterior illumination lamp supply circuit terminal.
4. Command the Courtesy Lamp 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 inoperative door switch.
   • 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 inoperative door switch.
5. If all circuits test normal, test or replace the appropriate lamp.