Power Door Locks Malfunction (Dead Locks)
Power Door Locks Malfunction (Dead Locks)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
Vehicles equipped with the UA2 option contain a reversible dead lock motor contained within each door latch assembly. Each dead lock motor is controlled by 2 circuits; the dead lock control circuit and the dead lock unlock control circuit. To dead lock a door, the body control module (BCM) locks the door by momentarily energizing the door lock relay. To complete the dead locking, the BCM momentarily applies voltage to the dead lock control circuit and ground to the door lock relay control circuit and the door latches will then dead lock.
Reference Information
Schematic Reference
Door Lock/Indicator Schematics (Door Lock/Indicator Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Power Door Latch Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON, command the doors to LOCK and UNLOCK by using the S84D door lock/window switch-driver, the all doors should perform the LOCK and UNLOCK function.
• If the doors do not LOCK or UNLOCK, refer to Power Door Locks Malfunction (Sedan/Wagon) (Power Door Locks Malfunction)Power Door Locks Malfunction (Dead Locks) .
2. Command the doors to LOCK with a scan tool and manually unlock each door, attempt to open the door by using the exterior door handles. The exterior door handles should be inoperative.
• If one or more doors open but not all, refer to Single Door Dead Lock Malfunction.
• If all doors open, refer to All Door Dead Lock Malfunction.
3. Command the doors to UNLOCK with a scan tool and attempt to open the door by using the exterior door handles. The exterior door handles should open the doors.
• If one or more doors open but not all, refer to Single Door Dead Lock Malfunction.
• If all doors do not open, refer to All Door Dead Lock Malfunction.
Circuit/System Testing
Single Door Dead Lock Malfunction
Note: The dead lock diagnostic assumes the door latches function normally.
1. Ignition OFF, disconnect the harness connector at the appropriate A23 door latch assembly.
2. Connect a test lamp between control circuit terminals listed below:
* A23D door latch assembly - driver control terminal 6 and control terminal 7 (Right hand drive)
* A23D door latch assembly - driver control terminal 1 and control terminal 2 (Left hand drive)
* A23P door latch assembly - passenger control terminal 1 and control terminal 2 (Right hand drive)
* A23P door latch assembly - passenger control terminal 6 and control terminal 7 (Left hand drive)
* A23LR door latch assembly - left rear control terminal 1 and control terminal 2
* A23RR door latch assembly - right rear control terminal 4 and control terminal 5
3. Command the doors to LOCK and UNLOCK with a scan tool, the test lamp should briefly illuminate while commanding the LOCK and UNLOCK states.
• If the test lamp is always OFF, test either control circuit for an open/high resistance between the connector and the circuit splice.
4. If all circuits test normal, test or replace the A23 door latch assembly
All Door Dead Lock Malfunction
1. Ignition OFF, disconnect the UNLCK relay.
2. Test for less than 30 ohm between the ground circuit terminal 87A and ground.
• If greater than the specified range, test the ground circuit for a short to voltage or an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal listed below and ground:
* B+ circuit terminal 86
* B+ circuit terminal 87
• 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 B+ circuit terminal 86 and the control circuit terminal 85.
5. Command the doors to UNLOCK with a scan tool. The test lamp should briefly illuminate during the UNLOCK command.
• 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 K9 BCM.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 BCM.
6. Ignition OFF, connect the UNLCK relay and disconnect the LCK relay.
7. Test for less than 30 ohm between the ground circuit terminals listed below and ground:
* Ground circuit terminal 86
* Ground circuit terminal 86
• If greater than the specified range, test the ground circuit for a short to voltage or an open/high resistance.
8. Connect a test lamp between the ground circuit terminal 86 and the control circuit terminal 85.
9. Command the doors to LOCK with a scan tool. The test lamp should briefly illuminate during the LOCK command.
• 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 K9 BCM.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
10. Ignition OFF, connect the LCK relay and disconnect the X2 harness connector at the theft deterrent alarm.
11. Test for less than 20 ohm between the control circuit terminal D and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the LCK relay
12. Connect a test lamp between the control circuit terminal D and ground.
13. Command the doors to LOCK with a scan tool. The test lamp should briefly illuminate during the LOCK command.
• 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, test or replace the LCK relay.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the LCK relay.
14. Test for less than 20 ohm between the control circuit terminal listed below and ground:
* Control circuit terminal C
* Control circuit terminal F
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance.
15. Connect at test lamp between the control circuit terminal C and the control circuit terminal D
16. Command the doors to UNLOCK with a scan tool. The test lamp should briefly illuminate during the UNLOCK command.
• If the test lamp does not illuminate, test the control circuit for a short to ground.
17. Connect at test lamp between the control circuit terminal F and the control circuit terminal D
18. Command the doors to UNLOCK with a scan tool. The test lamp should briefly illuminate during the UNLOCK command.
• If the test lamp does not illuminate, test the control circuit for a short to ground.
19. If all circuits test normal, replace the theft deterrent alarm.
Component Testing
Door Latch Assembly Test
1. Ignition OFF, disconnect the harness connector at the appropriate A23 door latch assembly.
2. Install a 25 A fused jumper wire between one of the control terminals and 12 V. Momentarily install a jumper wire between the other control terminal and ground. Reverse the jumper wires at least two times, the A23 door latch assembly should perform the LOCK and UNLOCK functions.
• If it does not perform as specified, replace the A23 door latch assembly.
Relay Test
1. Ignition OFF, disconnect the appropriate relay.
2. Test for 60-200 ohm between terminals 85 and 86.
• If not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
• If less than the specified value, replace the relay.
4. Test for less than 2 ohm between terminals 30 and 87 A.
• If greater than the specified value, replace the relay.
5. Install a 3 A fused jumper wire between terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohm between terminals 30 and 87.
• If greater than the specified value, replace the relay
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Front Side Door Outside Handle Replacement (Front and Rear Doors with ATH) (Service and Repair)Front Side Door Outside Handle Replacement (Front Door with ATH) (Service and Repair)Front Side Door Outside Handle Replacement (Without ATH) (Service and Repair)
* Front Side Door Latch Replacement (Sedan/Wagon) (Service and Repair)
* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Rear Side Door Latch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for door lock/window switch-driver, door lock/window switch passenger and BCM, replacement, setup and programming