Power Door Locks Inoperative
Power Door Locks Inoperative
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
Front Doors
The driver door lock switch is wired to the driver door switch assembly (DDSA). The lock switch receives a constant ground source. There are 2 signal circuits, one for lock signal, and one for unlock signal. When the switch is activated for a lock or unlock function, the normally open switch contacts for that function are closed and provide a switched ground signal to the DDSA. These switch activations are detected and processed by the DDSA and then communicated to the driver door module (DDM) via a GMLAN message.
The front passenger door lock switch is wired to the passenger front door module (PDM). The lock switch receives a constant ground source. There are 2 signal circuits, one for lock signal, and one for unlock signal. When the switch is activated for a lock or unlock function, the normally open switch contacts for that function are closed and provide a switched ground signal to the PDM.
The front doors do not have traditional door lock actuators. They have electronically controlled door latches that will operate depending on the status of the door lock system. This status is determined by the front door modules and the last known state of the lock system. If the last known state is LOCK, the latches will not release when the door handles are operated. If the last known state is UNLOCK, the latches will release when the door handles are operated. The front doors are also equipped with red door lock status indicators. The front door modules will supply power and ground to the indicators to illuminate them when the lock system is in a virtual state of lock. The indicators will not continuously illuminate when the vehicle is locked. They will illuminate for approximately 5 seconds after a lock switch activation or after a door handle has been operated and the front door modules are in a virtual state of lock.
Rear Doors
Each rear door lock actuator is powered and controlled by the right rear door module (RRDM) and left rear door module (LRDM) mounted in the individual door. The remote control door lock receiver (RCDLR), which is the master control for the door lock system, determines when the lock and unlock functions are permitted. The RCDLR receives and examines lock and unlock function requests from the individual door modules via GMLAN serial data, or from RFA transmissions. The RCDLR also examines the transmission shift selector position and power mode information available over the GMLAN serial data circuits. If the RCDLR determines that all conditions are correct for a lock or unlock function, a message is sent via GMLAN serial data back to the individual door modules commanding them to perform the lock or unlock function requested.
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 Locks Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning)
Circuit/System Verification
1. Ignition ON, observe the scan tool door lock switch parameter located in the driver door switch data display menu while activating the driver door lock switch to the LOCK and UNLOCK positions. The reading should toggle between LOCK, UNLOCK, and IDLE as the switch is activated.
• If the reading does not change between the commanded states, refer to Door Lock Switch Malfunction - Driver.
2. Ignition ON, observe the scan tool door lock switch parameter located in the passenger door module (PDM) data display menu while activating the passenger door lock switch to the LOCK and UNLOCK positions. The reading should toggle between LOCK, UNLOCK, and IDLE as the switch is activated.
• If the reading does not change between the commanded states, refer to Door Lock Switch Malfunction - Passenger.
3. Ignition ON, with a scan tool command the door lock/unlock test for the left rear passenger door lock. The left rear door lock should LOCK and UNLOCK when commanded.
• If the door lock does not LOCK and UNLOCK when commanded, refer to Door Lock Malfunction - Rear.
4. Ignition ON, with a scan tool command the door lock/unlock test for the right rear passenger door lock. The right rear door lock should LOCK and UNLOCK when commanded.
• If the door lock does not LOCK and UNLOCK when commanded, refer to Door Lock Malfunction - Rear.
5. Ignition ON, observe the scan tool door open switch parameter for each door while opening and closing each door one at a time. The reading should toggle between OPEN and CLOSED.
• If the reading does not change between the commanded states, refer to Door Open Switch Malfunction.
Circuit/System Testing
Door Lock Switch Malfunction - Driver
1. Ignition OFF, disconnect the harness connector at the driver door lock switch.
2. Ignition OFF, scan tool OFF, test for less than 10.0 ohms of resistance between the ground circuit terminal C and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool door lock switch parameter located in the driver door switch menu displays IDLE.
• If not the specified value, test the appropriate signal circuit for a short to ground. If the circuit tests normal, replace the DDSA.
4. Install a 3A fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool door lock switch parameter displays LOCK.
• If not the specified value, test the signal circuit terminal D for a short to voltage or an open/high resistance. If the circuit tests normal, replace the DDSA.
5. Install a 3A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool door lock switch parameter displays UNLOCK.
• If not the specified value, test the signal circuit terminal E for a short to voltage or an open/high resistance. If the circuit tests normal, replace the DDSA.
6. If all circuits test normal, test or replace the driver door lock switch.
Door Lock Switch Malfunction - Passenger
1. Ignition OFF, disconnect the harness connector at the passenger door lock switch.
2. Ignition OFF, scan tool OFF, test for less than 10.0 ohms of resistance between the ground circuit terminal 1 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool door lock switch parameter located in the passenger door module (PDM) menu displays IDLE.
• If not the specified value, test the appropriate signal circuit for a short to ground. If the circuit tests normal, replace the front PDM.
4. Install a 3A fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool door lock switch parameter displays LOCK.
• If not the specified value, test the signal circuit terminal D for a short to voltage or an open/high resistance. If the circuit tests normal, replace the front PDM.
5. Install a 3A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool door lock switch parameter displays UNLOCK.
• If not the specified value, test the signal circuit terminal E for a short to voltage or an open/high resistance. If the circuit tests normal, replace the front PDM.
6. If all circuits test normal, test or replace the passenger door lock switch.
Power Door Lock Malfunction - Rear
1. Ignition OFF, disconnect the harness connector at the inoperative rear door latch assembly.
2. Ignition OFF, test for less than 5 ohms of resistance between the lock control circuit 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, replace the appropriate door control module.
3. Ignition OFF, test for less than 5 ohms of resistance between the unlock control circuit 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, replace the appropriate door control module.
4. Connect a test lamp between the lock control circuit and the unlock control circuit.
5. Command the appropriate door lock/unlock test with a scan tool. The test lamp should turn ON when commanding the LOCK and UNLOCK states.
• If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the appropriate door control module.
6. If all circuits test normal, test or replace the inoperative door latch assembly.
Power Door Lock Deadbolt Malfunction (European)
1. Ignition OFF, disconnect the harness connector at the inoperative door latch assembly.
2. Ignition OFF, scan tool OFF, test for less than 5.0 ohms of resistance between the deadbolt control circuit terminal and ground.
• If greater than the specified range, test the deadbolt control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the appropriate door control module.
3. Ignition OFF, scan tool OFF, test for less than 5.0 ohms of resistance between the unlock control circuit terminal and ground.
• If greater than the specified range, test the unlock control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the appropriate door control module.
4. Connect a test lamp between the deadbolt lock control circuit terminal and the door unlock control circuit terminal.
5. Perform the DOOR DEADBOLT LOCK/UNLOCK test with a scan tool. The test lamp should turn ON when performing the DOOR LOCK/UNLOCK test.
• If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the appropriate door control module.
6. If all circuits test normal, test or replace the inoperative door latch assembly.
Door Open Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the inoperative door latch assembly.
2. Ignition OFF, scan tool OFF, test for less than 10.0 ohms of resistance between the ground circuit and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Door Open Switch parameter is CLOSED.
• If the scan tool displays OPEN, test the door open switch signal circuit for a short to ground. If the circuit tests normal, replace the appropriate door control module.
4. Install a 3A fused jumper wire between the door open switch signal circuit and ground. Verify the scan tool door open switch parameter is OPEN.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the appropriate door control module.
5. If all circuits test normal, test or replace the inoperative door latch assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Door Lock Switch Replacement (Service and Repair)
* Rear Door Lock Replacement (Rear Door Lock Replacement)
* Front Side Door Lock Replacement (Front Side Door Lock Replacement)
* Control Module References (Programming and Relearning) for DDM, PDM, LRDM, or RRDM replacement, setup and programming