Power Door Locks Malfunction (Coupe)
Power Door Locks Malfunction (Coupe)
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 door lock/window switch and passenger door lock/window switch each provide a 12V signal to their respective interior and exterior door handle switches. When a door handle switch is pressed, the voltage within the signal circuit will drop to 0V, the door lock/window switch will detect the voltage drop and will provide voltage to one control circuit and ground to the other control circuit of the door latch causing the door latch to activate releasing the door allowing it to be push or pulled open.
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 the LOCK position, the driver door lock/window switch and the passenger door lock/window switch will disable the interior and exterior door handle switches preventing the doors from being open.
Diagnostic Aids
It was noted that an open/high resistance in the low reference circuit of the interior driver door handle switch that the switch will continue to function normally only when the interior backlights were OFF and when the interior backlights were ON, the interior driver door handle switch would become inoperative.
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 Control Module References for scan tool information
Circuit/System Verification
1. With the doors unlocked, observe the scan tool Door Lock Actuator Cmd while pressing and releasing the B27E door handle switch-driver interior. The value should briefly change from Off to Lock to Off each time the switch is pressed.
• If value does not change, refer to Interior Door Handle Switch Malfunction.
2. With the doors unlocked, observe the scan tool Door Lock Actuator Cmd while pressing and releasing the B27D door handle switch - driver exterior. The value should briefly change from Off to Lock to Off each time the switch is pressed.
• If value does not change, refer to Exterior Door Handle Switch Malfunction.
3. With the doors unlocked, command the driver door to release by pressing a B27 door handle switch - driver, listen as the A23D door latch assembly-driver activates.
• If the A23D door latch assembly-driver is inoperative, refer to Door Latch Inoperative
4. With the doors unlocked, observe the scan tool Door Lock Actuator Cmd while pressing and releasing the B27F door handle switch-passenger interior. The value should briefly change from Off to Lock to Off each time the switch is pressed.
• If value does not change, refer to Interior Door Handle Switch Malfunction.
5. With the doors unlocked, observe the scan tool Door Lock Actuator Cmd while pressing and releasing the B27B door handle switch-passenger exterior. The value should briefly change from Off to Lock to Off each time the switch is pressed.
• If value does not change, refer to Exterior Door Handle Switch Malfunction.
6. With the doors unlocked, command the passenger door to release by pressing a A27 door handle switch - passenger, listen as the A23P door latch assembly-passenger activates.
• If the A23P door latch assembly-passenger is inoperative, refer to Door Latch Inoperative
Circuit/System Testing
Interior Door Handle Switch Malfunction
1. Ignition OFF, scan tool OFF, doors closed, disconnect the harness connector at the appropriate interior B27 door handle switch.
2. After 10 minutes, test for less than 10 ohm between the low reference circuit terminal A and ground.
• If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the appropriate S84 door lock/window switch
3. Ignition ON, test for greater than 10V between the signal circuit terminal listed below and ground.
* Signal circuit terminal B
* Signal circuit terminal C
• 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, replace the S84 door lock/window switch.
4. If all circuits test normal, test or replace the interior B27 door handle switch.
Exerior Door Handle Switch Malfunction
1. Ignition OFF, scan tool OFF, doors closed, disconnect the harness connector at the appropriate exterior B27 door handle switch.
2. After 10 minutes, test for less than 10 ohm between the ground circuit terminal C and ground.
• If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance.
3. Ignition ON, test for greater than 10V between the signal circuit terminal listed below and ground.
* Signal circuit terminal A
* Signal circuit terminal D
• 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, replace the S84 door lock/window switch.
4. If all circuits test normal, test or replace the exterior B27 door handle switch.
Door Latch Inoperative
1. Ignition OFF, doors closed, scan tool OFF, disconnect the harness connector at the A23 door latch.
2. Connect a test lamp between the control circuit terminal listed below:
* Control circuit terminal 3 and control circuit terminal 4 - A23D door latch assembly-driver
* Control circuit terminal 8 and control circuit terminal 9 - A23P door latch assembly-passenger
Note: Verify that the door is unlocked by pressing the appropriate switch on the S84 door lock/window switch.
3. Ignition ON, command the A23 door latch assembly to UNLATCH by pressing and releasing a door handle switch, the test lamp should briefly illuminate during the UNLATCH command.
• If the test lamp is always OFF, test either control circuit for a short to ground or an open/high resistance. If both circuits tests normal, replace the S84 door lock/window switch.
• If the test lamp is always ON, test either control circuit for a short to vootage. If both circuits tests normal, replace the S84 door lock/window switch.
4. If all circuits test normal, test or replace the A23 door latch assembly.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Front Side Door Outside Handle Replacement (Without ATH) Front Side Door Outside Handle Replacement (Without ATH)Front Side Door Outside Handle Replacement (Front Door with ATH) Front Side Door Outside Handle Replacement (Front Door with ATH)Front Side Door Outside Handle Replacement (Front and Rear Doors with ATH) Front Side Door Outside Handle Replacement (Front and Rear Doors with ATH)
* Door Latch Release Switch Bezel Replacement (Coupe) Door Latch Release Switch Bezel Replacement (Coupe)
* Front Side Door Latch Replacement (Sedan/Wagon) Front Side Door Latch Replacement (Sedan/Wagon)Front Side Door Latch Replacement (Coupe) Front Side Door Latch Replacement (Coupe)
* Control Module References Control Module References for door lock/window switch-driver and door lock/window switch-passenger, replacement, setup and programming