Power Door Locks Malfunction (-AXE)
Power Door Locks Malfunction (-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 body control module (BCM) provides battery positive voltage and ground to the appropriate lock and unlock control circuits of the door lock and unlock relays. The lock control circuits of the driver and passenger door latch assemblies share a common relay; however, the unlock control circuits have separate relays. The system is designed this way so that the keyless entry transmitter may be used to unlock only the driver door.
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 V on the signal circuit.
The BCM, upon receipt of a lock switch lock signal, will switch the all lock relay control circuit to battery positive voltage. This will energize the LCK relay. The relay will supply voltage to the door lock actuator lock control circuits to one side of the lock actuator. Since the opposing side of the lock actuators are connected to ground through the other lock actuator control circuit and the normally closed contacts of the lock or unlock relay, the doors will then lock appropriately. The remaining unlock relays receive voltage from the underhood fuse block, the BCM upon receipt of a unlock signal or driver door unlock signal will switch the appropriate unlock relay to ground. This will energize the appropriate unlock relay. The relay will supply voltage to the appropriate door unlock control circuits to one side of the appropriate lock actuator. Since the opposing side of the lock actuators are connected to ground through the other lock actuator control circuits and the normally closed contact of the lock relay, the doors will then unlock appropriately.
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 Door Lock/Indicator Schematics
Connector End View Reference
Component Connector End Views A/C Compressor Clutch
Description and Operation
Power Door Locks Description and Operation (-AXE) Power Door Locks Description and Operation (-AXE)Power Door Locks Description and Operation (AXE) Power Door Locks Description and Operation (AXE)
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 Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, observe the scan tool Driver Door Lock Sw, Driver Door Unlock Sw. parameters while using the driver door lock/window switch. The parameter should change between Inactive and Active.
• If the parameter does not change between commanded states, refer to Driver Door Lock Switch Malfunction.
2. Observe the scan tool Psgr Door Lock Sw. and Psgr Door Unlock Sw. parameters while using the passenger door lock/window switch. The parameter should change between Inactive and Active.
• If the parameters do not change, refer to Passenger Door Lock Switch Malfunction
3. Verify the function of the driver and passenger door lock knobs by manually moving the door lock knob between the LOCK and UNLOCK positions, all the door lock knobs should move between the LOCK and UNLOCK positions without binding or require excessive force.
• If a 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.
4. Command the driver door, passenger door and rear door latches to LOCK and UNLOCK with the scan tool, all the doors should perform the LOCK and UNLOCK functions.
• If the driver door does not UNLOCK, refer to Driver Door Unlock Relay Malfunction.
• If the passenger or rear doors do not UNLOCK, refer to Door Unlock Relay Malfunction.
• If one or more doors do not LOCK, refer to Door Lock Relay Malfunction.
Circuit/System Testing
Driver Door Lock Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the driver door lock/window switch.
2. Test for less than 1 ohms between the ground circuit terminal B and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Driver Door Lock Sw. parameter is Inactive.
• If not the specified parameter, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the BCM.
* Z88 terminal D
* WDA terminal E
4. Install a 3 A fused jumper wire between the lock signal circuit terminal listed below and ground. Verify the scan tool Driver Door Lock Sw. parameter is Active.
* Z88 terminal D
* WDA terminal E
• 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
5. Verify the scan tool Driver Door Unlock Sw. parameter is Inactive.
• If not the specified parameter, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the BCM.
* Z88 terminal E
* WDA terminal D
6. Install a 3A fused jumper wire between the signal circuit terminal listed below and ground. Verify the scan tool Driver Door Unlock Sw. parameter is Active.
* Z88 terminal E
* WDA terminal D
• 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 driver door lock/window switch.
Passenger Door Lock Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the passenger door lock/window switch.
2. Test for less than 1 ohms between the ground circuit terminal B and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Psgr. Door Lock Sw. parameter is Inactive.
• If not the specified parameter, test the signal circuit terminal E for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3 A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool Psgr. 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.
5. Verify the scan tool Psgr. Door Unlock Sw. parameter is Inactive.
• If not the specified parameter, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the BCM.
6. Install a 3 A fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool Psgr. 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 passenger door lock/window switch.
Driver Door Unlock Relay 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 LT/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 LT/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 LT/UNLCK relay and disconnect the harness connector at the driver door latch.
9. Test for less than 5 ohms between the control circuit terminal 2 and ground.
• 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 LT/UNLCK relay.
10. Connect a test lamp between control circuit terminal 2 and ground.
11. Ignition ON, 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 ground. If the circuit tests normal, test or replace the LT/UNLCK relay.
12. If all circuits test normal, test or replace the driver 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 circuit terminal 85 and the B+ circuit terminal 86.
7. Command the Passenger Door(s) Unlock with a scan tool. The test lamp should illuminate while 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 appropriate door latch.
9. Test for less than 5 ohms between the control circuit terminal of the door latch listed below and ground:
* Left rear door latch terminal 2
* Passenger door latch terminal 5.
* 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. Ignition ON, connect a test lamp between the control circuit terminal listed below and ground:
* Left rear door latch terminal 2
* Passenger door latch terminal 5.
* Right rear door latch terminal 5
11. Ignition ON, command the Passenger Door(s) Unlock with a scan tool. The test lamp should illuminate while 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, verify the harness connector for the appropriate 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 door latch is firmly seated and secure, refer to Door Lock Circuit Testing.
Door Lock Circuit Testing
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 control circuit terminal 85 and the B+ circuit terminal 86.
7. Command the Lock All Doors with a scan tool. The test lamp should illuminate while commanding the LOCK 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 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:
* Driver door latch terminal 3.
* Left rear door latch terminal 3
* Passenger door latch terminal 6.
* 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:
* Driver door latch terminal 3.
* Left rear door latch terminal 3
* Passenger door latch terminal 6.
* Right rear door latch terminal 6
11. Ignition ON, command the Lock All Doors with a scan tool. The test lamp should illuminate while 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 Lock Switch Test
1. Ignition OFF, disconnect the harness connector at the appropriate door lock/window switch.
2. Test for infinite resistance between the signal terminals D and E and the ground terminal B with the switch in the open position.
• If less than the specified value, replace the door lock switch.
3. Test for less than 2 ohms between the signal terminal E and the ground terminal B with the switch in the lock position.
• If greater than the specified range, replace the door lock/window switch.
4. Test for less than 2 ohms between the signal terminal D and the ground terminal B with the switch in the unlock position.
• If greater than the specified range, replace the door lock/window switch.
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 and 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)
* Body Control Module Replacement Service and Repair