Circuit/System Testing
WARNING: This page is about a different car, the 2009 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
Door Open Switch Malfunction - Front
- Ignition OFF, disconnect the harness connector at the inoperative door latch assembly.
- Ignition OFF and the appropriate door control module fuse removed, test for less than 5 ohms between the appropriate ground circuit terminal listed below and ground.
- Driver Front Door Latch Assembly terminal 4
- Passenger Front Door Latch Assembly terminal 1
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the door control module
- Ignition ON, verify the appropriate scan tool Door Open Sw. parameter is Inactive.
- If not the specified value, test the appropriate signal circuit listed below for a short to ground. If the circuit tests normal, replace the appropriate door control module.
- Driver front door latch assembly terminal 1
- Passenger front door latch assembly terminal 4
- If not the specified value, test the appropriate signal circuit listed below for a short to ground. If the circuit tests normal, replace the appropriate door control module.
- Install a 3A fused jumper wire between the appropriate signal circuit terminal listed below and ground. Verify the related scan tool Door Open Sw. parameter is Open.
- Driver front door latch assembly terminal 1
- Passenger front door latch assembly terminal 4
- 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 door control module.
- If all circuits test normal, test or replace the inoperative door latch assembly.
Door Open Switch Malfunction - Rear or Middle
- Ignition OFF, disconnect the harness connector at the appropriate rear door lock assembly.
- Test for less than 5 ohms between the appropriate ground circuit terminal listed below and ground.
- Left rear door lock terminal 4
- Left middle door lock terminal 4
- Right rear door lock terminal 1
- Right middle door lock terminal 1
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, all doors closed, verify the scan tool Ctsy. Lamp Actv. Reason. parameter is Door Closed.
- If not the specified value, test the appropriate signal circuit listed below for a short to ground. If the circuit tests normal, replace the BCM.
- Left rear door lock terminal 1
- Left middle door lock terminal 1
- Right rear door lock terminal 4
- Right middle door lock terminal 4
- If not the specified value, test the appropriate signal circuit listed below for a short to ground. If the circuit tests normal, replace the BCM.
- Install a 3A fused jumper wire between the appropriate signal circuit terminal listed below and ground. Verify the scan tool Ctsy. Lamp Actv. Reason parameter is Door Open.
- Left rear door lock terminal 1
- Left middle door lock terminal 1
- Right rear door lock terminal 4
- Right middle door lock terminal 4
- If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
- If all circuits test normal, test or replace the door latch assembly.
Dome Lamp Switch Malfunction
- Ignition OFF, disconnect the harness connector at the headlamp switch.
- Verify that a test lamp illuminates between the ground circuit terminal 8 and B+.
- If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
- Ignition ON, all doors closed, verify the scan tool Ctsy. Lamp Actv. Reason parameter is Off or Door Closed.
- If not the specified value, test the signal circuit terminal 12 for a short to ground. If the circuit tests normal, replace the BCM.
- Install a 3A fused jumper wire between the signal circuit terminal 12 and ground. 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.
- If all circuits test normal, test or replace the headlamp switch.
Courtesy/Reading Lamps Circuit Malfunction - with Courtesy Lamp Module
- Ignition OFF, disconnect the X3 and X4 harness connectors at the BCM.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminals listed below and ground.
- B+ terminal 2 X3
- B+ terminal 2 X4
- 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 related courtesy lamp supply voltage circuits for a short to ground.
- Ignition OFF, connect the harness connectors at the BCM.
- Disconnect the harness connector at the courtesy lamp module.
- Ignition OFF, test for less than 5 ohms between the ground circuit terminal 7 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify that a test lamp illuminates between the control circuit terminal 8 and ground.
- 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.
- Door OPEN, verify that a test lamp illuminates between the control circuit terminal 6 and ground.
- 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.
- Disconnect the harness connector at the inoperative courtesy lamp.
- Ignition OFF, test for less than 5 ohms between the ground circuit terminal B and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit test normal, replace the courtesy lamp module.
- Verify that a test lamp illuminates between the control circuit terminal A and ground.
- 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 courtesy lamp module.
- Door OPEN, verify that a test lamp illuminates between the control circuit terminal C and ground.
- 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 courtesy lamp module.
- If all circuits test normal, test or replace the courtesy lamp.
Front Door Courtesy Lamp Malfunction
- Ignition OFF, disconnect the harness connector at the appropriate door courtesy lamp.
- Ignition OFF and the appropriate door control module fuse removed, test for less than 5 ohms between the ground circuit terminal B and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the appropriate door control module.
- Connect a test lamp between the control circuit terminal A and the ground circuit terminal B.
- Ignition ON, command the appropriate Door Switch Puddle/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 voltage. If the circuit tests normal, replace the appropriate door control module.
- 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 appropriate door control module.
- If all circuits test normal, test or replace the door courtesy lamp.
Courtesy Lamp Circuit Malfunction - w/o Courtesy Lamp Module
- Ignition OFF, disconnect the harness connector at the inoperative courtesy lamp.
- Ignition OFF, test for less than 5 ohms between the ground circuit terminal B and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Connect a test lamp between the control circuit terminal A and ground.
- Ignition ON, 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 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 inoperative courtesy lamp.
Inadvertent Power Courtesy Lamps Malfunction
- Ignition OFF, disconnect the X3 harness connector at the BCM.
- Verify that a test lamp illuminates between the 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. If the circuit tests normal and the B+ circuit fuse is open, test the inadvertent power courtesy lamp control circuits for a short to ground.
- Ignition OFF, connect the harness connector at the BCM.
- Disconnect the harness connector at the inoperative lamp.
- Test for less than 5 ohms between the ground circuit terminal B and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- 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 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 inoperative lamp.
Overhead Console Courtesy/Reading Lamp Malfunction - Limo/Hearse
- Ignition OFF, disconnect the X3, X4 harness connectors at the BCM.
- Verify that a test lamp illuminates between the B+ circuit terminals listed below and ground.
- B+ terminal 2 X3
- B+ terminal 2 X4
- 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 related courtesy lamp supply voltage circuits for a short to ground.
- Ignition OFF, connect the harness connectors at the BCM.
- Disconnect the harness connector at the overhead console lamp.
- Test for less than 5 ohms between the ground circuit terminal A and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Verify that a test lamp illuminates between the control circuit terminal C and ground.
- 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.
- Remove the OVRHD LAMPS LIMO Relay from the rear fuse block.
- Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 1 and ground.
- If the test lamp illuminates, test the control circuit for a short to voltage.
- Ignition OFF, test for less than 5 ohms between the ground circuit terminal 3 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Verify that a test lamp illuminates between the control circuit terminal 5 and ground.
- If the test lamp does not illuminate, test the control circuit for an open/high resistance.
- Connect the harness connector at the overhead console lamp.
- Connect a 3A fused jumper wire between the control circuit terminal 5 and the control circuit terminal 1. Verify the overhead lamp courtesy lamp is illuminated.
- If the courtesy lamp does not illuminate, test the control circuit terminal 5 for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the overhead courtesy lamp.
- Connect a test lamp between the control circuit terminal 4 and ground.
- Ignition ON, 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 voltage. If the circuit tests normal, replace the BCM.
- If the test lamp is always OFF, test the supply voltage 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 overhead lamp relay.
Roof Rail Courtesy/Reading Lamp Malfunction - Limo/Hearse
- Ignition OFF, disconnect the X3 and X4 harness connectors at the BCM.
- Verify that a test lamp illuminates between the B+ circuit terminals listed below and ground.
- B+ terminal 2 X3
- B+ terminal 2 X4
- 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 related courtesy lamp supply voltage circuits for a short to ground.
- Ignition OFF, connect the harness connectors at the BCM.
- Disconnect the harness connector at the inoperative roof rail courtesy/reading lamp.
- Test for less than 5 ohms between the ground circuit terminal B and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Door open, verify that a test lamp illuminates between the control circuit terminal A and ground.
- 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.
- Verify that a test lamp illuminates between the control circuit terminal C and ground.
- 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.
- If all circuits test normal, test or replace the inoperative roof rail reading lamp.