Power Door Locks Inoperative
Power Door Locks InoperativeDiagnostic Instructions
^ Perform the [Diagnostic System Check - Vehicle Diagnostic Information] prior to using this diagnostic procedure. Diagnostic System Check - Vehicle Diagnostic Information
^ Review [Strategy Based Diagnosis] for an overview of the diagnostic approach. Strategy Based Diagnosis
^ [Diagnostic Procedure Instructions - Vehicle Diagnostic Information] provides an overview of each diagnostic category. Diagnostic Procedure Instructions - Vehicle Diagnostic Information
Diagnostic Fault Information
Circuit/System Description
The BCM supplies and monitors a reference voltage to the door lock switch through the door lock switch lock/unlock signal circuit. The door lock switch also receives a constant ground source. If a door lock switch is placed in the lock position or unlock position, the reference voltage is taken directly to ground and the BCM detects 0.0 volts on the signal circuit. The BCM, upon receipt of a door lock switch lock or unlock signal, will switch the appropriate door lock actuator control circuits to battery positive voltage. The opposing side of the door lock actuators are connected to ground internally within the BCM through the other door lock actuator control circuit and the doors will lock or unlock appropriately.
Circuit/System Verification
1. Ignition ON, observe the scan tool Driver Door Lock Sw, Psgr Door Lock Sw, Driver Door Unlock Sw and Psgr Door Unlock Sw parameters while using the appropriate door lock switch. The parameter should change between Inactive and Active.
^ If the parameter does not change between commanded states, refer to Door Lock Switch Malfunction.
2. Command the door latches to LOCK and UNLOCK with the scan tool, the doors should LOCK and UNLOCK.
^ If a door latch does not LOCK or UNLOCK, refer to Door Lock Malfunction.
Circuit/System Testing
Door Lock Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Test for less than 1.0 ohmbetween the ground circuit terminal 3 and ground.
^ If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Door Lock Sw parameter is Inactive.
^ If not the specified parameter, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.
4. Verify the scan tool Door Unlock Sw parameter is Inactive.
^ If not the specified parameter, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the BCM.
5. Install a 3 amp fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool Door Lock Sw parameter is Active.
^ If not the specified parameter, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
6. Install a 3 amp fused jumper wire between the signal circuit terminal 2 and ground. Verify the scan tool Door Unlock Sw parameter is Active.
^ If not the specified parameter, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
7. If all circuits test normal, test or replace the door lock switch.
Door Lock Malfunction
1. Ignition OFF, disconnect the X1, X2 and X3 harness connectors at the I/P fuse block.
2. Test for less than 1.0 ohm between the ground circuit terminal 25 and ground.
^ If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition OFF, verify that a test lamp illuminates between the B+ circuit terminal 3 and ground.
^ If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance
4. Connect a test lamp between the control circuit terminal 42 and ground.
5. Command the doors to LOCK with a scan tool. The test lamp should briefly illuminate while commanding the LOCK state.
^ 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.
6. Connect a test lamp between the control circuit terminal 41 and B+.
7. Command the doors to UNLOCK with a scan tool. The test lamp should briefly illuminate while commanding the UNLOCK state.
^ 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 and open/high resistance. If the circuit tests normal, replace the BCM.
8. Connect a test lamp between the control circuit terminal 8 and B+.
9. Command the driver door to UNLOCK with a scan tool. The test lamp should briefly illuminate while commanding the UNLOCK state.
^ 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 and open/high resistance. If the circuit tests normal, replace the BCM.
10. Ignition OFF, connect the X1, X2 and X3 harness connectors at the I/P fuse block and disconnect the harness connector at the appropriate door latch.
11. Test for less than 1 ohm between the control circuit terminal and ground of the appropriate door latch listed below:
^ Driver door latch control circuit terminal 2
^ Driver door latch control circuit terminal 3
^ Left rear door latch control circuit terminal 1
^ Left rear door latch control circuit terminal
^ Right rear door latch control circuit terminal 5
^ Right rear door latch control circuit terminal 6
^ Front passenger door latch control circuit terminal 5
^ Front passenger door latch control circuit terminal
^ If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the I/P fuse block.
12. Connect a test lamp between control circuit terminals of the appropriate door latch listed below:
^ Driver door latch control circuit terminal 2 and control circuit terminal 3
^ Left rear door latch control circuit terminal 1 and control circuit terminal 2
^ Right rear door latch control circuit terminal 5 and control circuit terminal 6
^ Front passenger door latch control circuit terminal 5 and control circuit terminal 6
13. Ignition ON, command the door latch to LOCK and UNLOCK with a scan tool. The test lamp should turn ON when commanding the LOCK and UNLOCK states.
^ If the test lamp remains OFF during either of the commands, test for a short to ground on both control circuits. If the circuits test normal, replace the I/P fuse block.
14. If all circuits test normal, test or replace the door latch.
Component Testing
Door Lock Switch Test
1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Test for infinite resistance between the signal terminals 2 and 1 and the ground terminal 3 with the switch in the open position.
^ If not the specified value, replace the door lock switch.
3. Test for less than 2-ohms between the signal terminal 1 and the ground terminal 3 with the switch in the LOCK position.
^ If greater than the specified range, replace the door lock switch.
4. Test for less than 2-ohms between the signal terminal 2 and the ground terminal 3 with the switch in the UNLOCK position.
^ If greater than the specified range, replace the door lock switch.
Door Latch Assembly
1. Ignition OFF, disconnect the harness connector at the appropriate door latch
2. Install a 15 amp fused jumper wire between the lock control terminal and 12 volts. Momentarily install a jumper wire between the unlock control terminal and ground. The door latch should perform the LOCK/ UNLOCK function.
^ If the function does not perform as specified, replace the door latch
3. Reverse the jumper wires; the door latch should perform the UNLOCK/LOCK function.
^ If the function does not perform as specified, replace the door latch.
Repair Instructions
Perform the [Diagnostic Repair Verification - Vehicle Diagnostic Information] after completing the diagnostic procedure. Diagnostic Repair Verification - Vehicle Diagnostic Information
^ [Door Lock Switch Replacement]
^ [Front Side Door Latch Replacement]
^ [Rear Side Door Latch Replacement]
^ [Control Module References] for BCM replacement, setup, and programming Programming and Relearning