Circuit/System Testing
WARNING: This page is about a different car, the 2011 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
The high intensity discharge system produces high voltage and current. To reduce the risk of severe shocks and burns:
- Never open the high intensity discharge system ballast or the arc tube assembly starter.
- Never probe between the high intensity discharge system ballast output connector and the arc tube assembly.
Turn Signal/Multifunction Switch Malfunction
- Ignition OFF, disconnect the X3 harness connector at the turn signal/multifunction switch.
- Test for less than 5 Ω between the ground circuit terminal G and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify the scan tool Left Turn Signal Switch parameter is Inactive.
- If not the specified value, test the signal circuit terminal F for a short to ground. If the circuit tests normal, replace the BCM.
- Verify the scan tool Right Turn Signal Switch parameter is Inactive.
- If not the specified value, test the signal circuit terminal H for a short to ground. If the circuit tests normal, replace the BCM.
- Install a 3 A fused jumper wire between the signal circuit terminal F and the ground circuit terminal G. Verify the scan tool Left Turn Signal Switch parameter is Active.
- 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.
- Install a 3 A fused jumper wire between the signal circuit terminal H and the ground circuit terminal G. Verify the scan tool Right Turn Signal Switch parameter is Active.
- 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.
- If all circuits test normal, test or replace the turn signal/multifunction switch.
Turn Signal Lamps Malfunction
- Ignition OFF, disconnect the X4 harness connector at the BCM.
- Ignition ON, verify a test lamp illuminates between the following B+ terminals and ground:
- B+ terminal 1
- B+ terminal 2
- B+ terminal 3
- If the test lamp does not illuminate, test the B+ circuit for an open/high resistance. If the circuit fuse is open, test the B+ circuit and the respective turn signal circuits for a short to ground.
- Ignition OFF, disconnect the harness connector at the inoperative turn signal lamp.
- Test for less than 5 Ω between the appropriate ground circuit terminal listed below and ground:
- Front headlamp assembly terminal A
- Tail lamp assembly terminal C - All Countries Except Japan, Korea, Taiwan
- Tail lamp assembly terminal H - Japan, Korea, Taiwan Only
- Repeater lamp terminal B - Japan, Korea, Taiwan Only
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Connect a test lamp between the appropriate control circuit terminal listed below and the ground:
- Front headlamp assembly terminal C
- Rear tail lamp assembly terminal B - All Countries Except Japan, Korea, Taiwan
- Rear tail lamp assembly terminal G - Japan, Korea, Taiwan Only
- Repeater lamp terminal A - Japan, Korea, Taiwan Only
- Ignition ON, command the inoperative turn signal 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 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.
- If all circuits test normal, test or replace the appropriate turn signal bulb.
Outside Rearview Mirror Turn Signal Indicator Malfunction
- Ignition OFF, disconnect the X1 harness connector at the inoperative outside rearview mirror.
- Connect a test lamp between the low reference circuit terminal 2 and B+.
- Ignition ON, command the appropriate LF or RF Turn Signal 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 low reference circuit for a short to ground. If the circuit tests normal, replace the door module.
- If the test lamp is always OFF, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the door module.
- Connect a test lamp between the control circuit terminal 1 and ground.
- Ignition ON, command the appropriate LF or RF Turn Signal 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 voltage.
- If the test lamp is always OFF, test the control circuit for an open/high resistance.
- If all circuits test normal, test or replace the outside rearview mirror lamp bulb.
Tail Lamp Outage Detection Malfunction
- Ignition OFF, disconnect the harness connector at the appropriate rear tail lamp assembly.
- Ignition ON, test for B+ between the signal circuit terminal D and ground.
- If less than B+, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
- Ignition ON, connect a test lamp between the signal circuit terminal D and ground. The test lamp should not illuminate.
- If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.
- If all circuits test normal, test or replace the tail lamp assembly.