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Power Door Locks Malfunction




Power Door Locks Malfunction (Sedan/Wagon)

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

The driver and front passenger power door lock switches are integral components of the driver door lock/window switch and passenger door lock/window switch. The switches consist of 2 positions, lock and unlock, and are in the normally open state. When placed in either the lock or unlock positions, the switches provide a direct input to their respective door lock/window switch. When a power door lock switch is operated to the lock or unlock position, the associated door lock/window switch responds by sending a serial data message indicating a change in the switch's position. This serial data message is received by the opposite door lock/window switch as well as the body control module (BCM). The driver door lock/window switch and passenger door lock/window switch respond to the lock/unlock request by activating their associated power door lock motors to the appropriate direction to lock or unlock the front doors. The BCM is responsible for controlling the left and right rear passenger door lock motors. The BCM, upon receipt of a lock or unlock serial data signal, will control either the rear door lock or unlock relay. When the appropriate door lock relay is energized, the rear power door lock motors will lock or unlock the rear doors.

Reference Information
Schematic Reference

Door Lock/Indicator Schematics (Door Lock/Indicator Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
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 driver door to LOCK and UNLOCK by using the S84D door lock/window switch-driver, the driver door should perform the LOCK and UNLOCK function.

• If the driver door does not LOCK or UNLOCK, refer to Driver Door Lock Malfunction.

2. Command the passenger door to LOCK and UNLOCK by using the S84P door lock/window switch-passenger, the passenger door should perform the LOCK and UNLOCK function.

• If the passenger door does not LOCK or UNLOCK, refer to Passenger Door Lock Malfunction.

3. Command the rear door latches to LOCK and UNLOCK with a scan tool, the rear doors should LOCK and UNLOCK while changing between the commanded states.

• If either rear door does not LOCK or UNLOCK refer to Rear Door Lock Malfunction.

4. With the doors closed and unlocked, pull the exterior driver door handle. The driver door should unlatch allowing the driver door to be pulled open.

• If the driver door does not perform as specified, refer to Exterior Door Handle Switch Malfunction.

5. With the doors closed and unlocked, pull the exterior passenger door handle. The passenger door should unlatch allowing the passenger door to be pulled open.

• If the passenger door does not perform as specified, refer to Exterior Door Handle Switch Malfunction.

Circuit/System Testing

Driver Door Lock Malfunction
1. Ignition OFF, disconnect the X1 harness connector at the S84D door lock/window switch-driver.
2. Test for less than 30 ohm between the ground circuit terminal 6 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 B+ circuit terminal 4 and ground.

• If the test lamp does not illuminate, test the B+ circuit terminal for a short to ground or an open/high resistance.

4. Ignition OFF, connect the X1 harness connector at the S84D door lock/window switch-driver and disconnect the harness connector at the A23D door latch-driver.
5. Test for less than 5 ohm between the control circuit terminal listed below and ground.

* Left hand drive-control circuit terminal 3
* Right hand drive-control circuit terminal 8

• If greater than specified value, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the S84D door lock/window switch-driver.

6. Test for less than 5 ohm between the control circuit terminal listed below and ground.

* Left hand drive-control circuit terminal 2
* Right hand drive-control circuit terminal 9

• If greater than specified value, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the S84D door lock/window switch-driver.

7. Connect a test lamp between the control circuit terminals listed below:

* Left hand drive-control circuit terminal 2 and control circuit terminal 3
* Right hand drive-control circuit terminal 8 and control circuit terminal 9

8. Ignition ON, command the driver door latch to LOCK and UNLOCK by using the driver door lock switch, the test lamp should briefly illuminate during the LOCK and UNLOCK command.

• If the test lamp does not illuminate during either of the commands, test either control circuit for a short to ground. If both circuits tests normal, replace the S84D door lock/window switch-driver.

9. If all circuits test normal, test or replace the A23D door latch-driver.

Passenger Door Lock Malfunction
1. Ignition OFF, disconnect the X1 harness connector at the S84P door lock/window switch-passenger.
2. Test for less than 30 ohm between the ground circuit terminal 6 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 B+ circuit terminal 4 and ground.

• If the test lamp does not illuminate, test the B+ circuit terminal for a short to ground or an open/high resistance.

4. Ignition OFF, connect the X1 harness connector at the S84P door lock/window switch-passenger and disconnect the harness connector at the A23P door latch-passenger.
5. Test for less than 5 ohm between the control circuit terminal listed and ground.

* Left hand drive-control circuit terminal 5
* Right hand drive-control circuit terminal 4

• If greater than specified value, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the S84P door lock/window switch-passenger.

6. Test for less than 5 ohm between the control circuit terminal listed below and ground.

* Left hand drive-control circuit terminal 6
* Right hand drive-control circuit terminal 3

• If greater than specified value, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the S84P door lock/window switch-passenger.

7. Connect a test lamp between the control circuit terminals listed below.

* Left hand drive-control circuit terminal 5 and control circuit terminal 6
* Right hand drive-control circuit terminal 4 and control circuit terminal 3

8. Ignition ON, command the passenger door latch to LOCK and UNLOCK by using the passenger door lock switch, the test lamp should briefly illuminate during the LOCK and UNLOCK command.

• If the test lamp does not illuminate during either of the commands, test either control circuit for a short to ground. If both circuits tests normal, replace the S84P door lock/window switch-passenger.

9. If all circuits test normal, test or replace the A23P door latch-passenger.

Rear Door 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 BCM.

6. Ignition OFF, connect the UNLCK relay and disconnect the LCK relay.
7. Test for less than 30 ohms between the ground circuit terminals listed below and ground:

* Ground circuit terminal 86
* Ground circuit terminal 87A

• 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 BCM.

10. Ignition OFF, connect the LCK relay and disconnect the harness connector at the appropriate A23 door latch-rear.
11. Test for less than 30 ohm between the control circuit terminal listed below and ground.

* A23LR door latch-left rear control circuit terminal 2
* A23RR door latch-right rear control circuit terminal 5

• 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 UNLCK relay.

12. Test for less than 30 ohm between the control circuit terminal listed below and ground.

* A23LR door latch-left rear control circuit terminal 3
* A23RR door latch-right rear control circuit terminal 6

• 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.

13. Connect a test lamp between the control circuit terminal listed below and ground.

* A23LR door latch-left rear control circuit terminal 2
* A23RR door latch-right rear control circuit terminal 5

14. 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, test or replace the UNLCK 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 UNLCK relay.

15. Connect a test lamp between the control circuit terminal listed below and ground.

* A23LR door latch-left rear control circuit terminal 3
* A23RR door latch-right rear control circuit terminal 6

16. 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.

17. If all circuits test normal, test or replace the A23 door latch assembly.

Exterior Door Handle Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate B27 door handle switch.
2. Test for less than 30 ohm between the ground circuit terminal listed below and ground.

* Ground terminal 1
* Ground terminal 4

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, test for greater than 10 V between the signal circuit terminal listed below and ground.

* Signal terminal 2
* Signal terminal 3

• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, S84 door lock/window switch.

4. If all circuits test normal, test or replace the B27 door handle switch.

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) (Front Side Door Outside Handle Replacement)Front Side Door Outside Handle Replacement (Front Door with ATH) (Front Side Door Outside Handle Replacement)Front Side Door Outside Handle Replacement (Without ATH) (Front Side Door Outside Handle Replacement)Front Side Door Outside Handle Replacement (Coupe Front Side Door Release Switch) (Front Side Door Outside Handle Replacement)
* Front Side Door Latch Replacement (Sedan/Wagon) (Service and Repair)Front Side Door Latch Replacement (Coupe) (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

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