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Power Door Locks Malfunction (AXC/AXE)




Power Door Locks Malfunction (AXC/AXE)

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 there respective door control module. When a power door lock switch is operated to the lock or unlock position, the associated door control module 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 control module 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.

Diagnostic Aids

Verify the smooth and consistent mechanical operation of each part of the door latch system prior to performing extensive electrical diagnostics

Any door that does not function smoothly or consistently, refer to Door Will Not Open/Close, Door Binding, or Locks, Handles, or Cylinders Do Not Function Door Will Not Open/Close, Door Binding, or Locks, Handles, or Cylinders Do Not Function.

Reference Information

Schematic Reference

Door Lock/Indicator Schematics (AXE) Door Lock/Indicator Schematics (AXE)Door Lock/Indicator Schematics (Except AXE) Door Lock/Indicator Schematics (Except AXE)

Connector End View Reference

Component Connector End Views A/C Compressor Clutch

Description and Operation

Power Door Locks Description and Operation (AXC/AXE) Power Door Locks (AXC/AXE)Power Door Locks Description and Operation (AXA) Power Door Locks (AXA)

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, observe the scan tool Driver Door Switch Door Lock Actuator Cmd. parameter while using the driver door lock/window switch and Passenger Door Switch Door Lock Actuator Cmd. parameter while using the passenger door lock/window switch. The parameters for each switch should change from Off to Lock and Unlock.

• If the parameters do not change, replace the appropriate door lock/window switch.

2. Verify the function of the driver door lock knob by manually moving the door lock knob between the LOCK and UNLOCK positions, the door lock knob should move between the LOCK and UNLOCK positions without binding or require excessive force.

• If the driver door lock knob does not function or requires excessive force, refer to Door Will Not Open/Close, Door Binding, or Locks, Handles, or Cylinders Do Not Function Door Will Not Open/Close, Door Binding, or Locks, Handles, or Cylinders Do Not Function.

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

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

4. Verify the function of the passenger door lock knob by manually moving the door lock knob between the LOCK and UNLOCK positions, the door lock knob should move between the LOCK and UNLOCK positions without binding or require excessive force.

• If the passenger door lock knob does not function or requires excessive force, refer to Door Will Not Open/Close, Door Binding, or Locks, Handles, or Cylinders Do Not Function Door Will Not Open/Close, Door Binding, or Locks, Handles, or Cylinders Do Not Function.

5. Command the passenger door to LOCK and UNLOCK with a scan tool, the passenger door should LOCK and UNLOCK while changing between the commanded states.

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

6. Verify the function of the rear door lock knob by manually moving the door lock knob between the LOCK and UNLOCK positions, the door lock knob should move between the LOCK and UNLOCK positions without binding or require excessive force.

• If the rear door lock knob does not function or requires excessive force, refer to Door Will Not Open/Close, Door Binding, or Locks, Handles, or Cylinders Do Not Function Door Will Not Open/Close, Door Binding, or Locks, Handles, or Cylinders Do Not Function.

7. Command the Lock All Doors and Passenger Door(s) Unlock with a scan tool, the left rear and right rear doors should LOCK and UNLOCK while changing between the commanded states.

• If a rear door does not LOCK, refer to Door Lock Relay Malfunction

• If a rear door does not UNLOCK, refer to Door Unlock Relay Malfunction

Circuit/System Testing

Driver Door Lock Malfunction

1. Ignition OFF, verify the harness connector for the driver door latch is firmly seated and secure.

• If not the specified condition, seat and secure the connector and perform the Circuit/System Verification.

2. If the harness connector for the driver door latch is firmly seated and secure, refer to Driver Door Lock Circuit Testing.

Driver Door Lock Circuit Testing

1. Ignition OFF, disconnect the harness connector at the driver door latch.

2. Ignition ON, connect a test lamp between the control circuit terminal 3 and control circuit terminal 2.

3. Command the Door Lock/Unlock with a scan tool. The test lamp should briefly illuminate when commanding the LOCK and UNLOCK states.

• If the test lamp is always OFF during either of the commands, test either control circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the driver door lock/window switch.

• If the test lamp is always ON, test either control circuit for a short to voltage. If the circuits test normal, replace the driver door lock/window switch.

4. If the circuits test normal, test or replace the driver door latch.

Passenger Door Lock Malfunction

1. Ignition OFF, verify the harness connector for the passenger door latch is firmly seated and secure.

• If not the specified condition, seat and secure the harness connector and perform the Circuit/System Verification.

2. If the harness connector for the passenger door latch is firmly seated and secure, refer to Passenger Door Lock Circuit Testing.

Passenger Door Lock Circuit Testing

1. Ignition OFF, disconnect the harness connector at the passenger door latch.

2. Ignition ON, connect a test lamp between the control circuit terminal 5 and control circuit terminal 6.

3. Command the Door Lock/Unlock with a scan tool. The test lamp should briefly illuminate when commanding the LOCK and UNLOCK states.

• If the test lamp is always OFF during either of the commands, test either control circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the passenger door lock/window switch.

• If the test lamp is always ON, test either control circuit for a short to voltage. If the circuits test normal, replace the passenger door lock/window switch.

4. If the circuits test normal, test or replace the passenger door latch.

Door Unlock Relay Malfunction

1. Ignition OFF, disconnect the UNLCK relay.

2. Test for less than 1 ohms between the ground circuit terminal 87A 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 does not illuminate between the control circuit terminal 30 and ground.

• If the test lamp illuminates, test the control circuit for a short to voltage.

4. Verify that a test lamp illuminates between the B+ circuit terminal 86 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, test or replace the UNLCK relay.

5. Verify that a test lamp illuminates between the B+ circuit terminal 87 and ground.

• If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

6. Connect a test lamp between the control circuit terminal 85 and the B+ circuit terminal 86.

7. Command the driver door to UNLOCK by using the driver door lock/window switch. The test lamp should illuminate when commanding the UNLOCK state.

• 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 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.

8. Ignition OFF, connect the UNLCK relay and disconnect the harness connector at the driver door latch.

9. Test for less than 5 ohms between the control circuit terminal listed below and ground:

* Left rear door latch terminal 2.

* Right rear door latch terminal 5.

• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the UNLCK relay.

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

* Left rear door latch terminal 2.

* Right rear door latch terminal 5.

11. Ignition ON, command the Passenger Door(s) Unlock with a scan tool. The test lamp should turn ON when commanding the UNLOCK state.

• If the test lamp is always OFF, test the control circuit for a short to ground. If the circuit tests normal, test or replace the UNLCK relay.

12. If all circuits test normal, test or replace the door latch.

Door Lock Relay Malfunction

1. Ignition OFF, disconnect the LCK relay.

2. Test for less than 1 ohms between the ground circuit terminal 87A 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 does not illuminate between the control circuit terminal 30 and ground.

• If the test lamp illuminates, test the control circuit for a short to voltage.

4. Verify that a test lamp illuminates between the B+ circuit terminal 86 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, test or replace the LCK relay.

5. Verify that a test lamp illuminates between the B+ circuit terminal 87 and ground.

• If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

6. Connect a test lamp between the circuit terminal 85 and the B+ circuit terminal 86.

7. Command the rear doors unlock 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 OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the 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.

8. Ignition OFF, connect the LCK relay and disconnect the harness connector at the appropriate door latch.

9. Test for less than 5 ohms between the control circuit terminal of the door lock listed below and ground:

* Left rear door latch terminal 3.

* Right rear door latch terminal 6.

• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the LCK relay.

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

* Left rear door latch terminal 3.

* Right rear door latch terminal 6.

11. Ignition ON, command the Lock All Doors with a scan tool. The test lamp should turn ON when commanding the LOCK state.

• If the test lamp is always OFF, test the control circuit for a short to ground. If the circuit tests normal, test or replace the LCK relay.

12. If all circuits test normal, test or replace the door latch.

Component Testing

Door Latch

1. Ignition OFF, disconnect the harness connector at the appropriate door latch.

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 door latch should perform the LOCK/ UNLOCK functions.

• If it does not perform as specified, replace the door latch.

Relay Test

1. Ignition OFF, disconnect the appropriate relay.

2. Test for 60-200 ohms 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 ohms between terminals 30 and 87A.

• If greater than the specified range, replace the relay.

5. Install a 3 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.

• If greater than specified range, replace the relay.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Front Side Door Latch Replacement Service and Repair

* Rear Side Door Latch Replacement Service and Repair

* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)

* Control Module References Programming and Relearning for BCM, driver door lock/window switch or passenger door lock/window switch replacement, programming and setup

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