For 1990-2009 cars

### Power Door Lock Components

The power door lock system consists of the following components:

• | Driver door lock switch--Provides a switched ground signal to the DDSA for both lock and unlock switch activations

• | Passenger front door lock switch--Provides a switched ground signal to the PDM for both lock and unlock switch activations

• | Driver door switch assembly (DDSA)--GMLAN device that communicates lock and unlock requests to the door modules

• | Driver door module (DDM)--GMLAN device that controls the driver door lock status indicator and deadbolt lock actuator on export vehicles

• | Passenger front door module (PDM)--GMLAN device that controls the front passenger door lock status indicator and deadbolt lock actuator on export vehicles

• | Left rear door module (LRDM)--GMLAN device that controls the left rear door lock actuator and deadbolt lock actuator on export vehicles

• | Right rear door module (RRDM)--GMLAN device that controls the left rear door lock actuator and deadbolt lock actuator on export vehicles

• | Driver door lock status indicator--Red LED located on driver door trim that illuminates when the lock system is in a virtual state of lock

• | Passenger front door lock status indicator--Red LED located on driver door trim that illuminates when the lock system is in a virtual state of lock

• | Left rear door latch assembly--Contains the door lock actuator and deadbolt lock actuator on export vehicles

• | Right rear door latch assembly--Contains the door lock actuator and deadbolt lock actuator on export vehicles

• | Remote control door lock receiver (RCDLR)--GMLAN device that receives RFA transmissions and communicates with the door modules for lock and unlock commands

• | Driver DR MOD fuse (15-amp)--Located in the left rear fuse block and is hot at all times.

• | FRT PASS DR MOD fuse (15-amp)--Located in the right rear fuse block and is hot at all times.

• | REAR DR MOD fuse (15-amp)--Located in the left rear fuse block and is hot at all times.

• | GMLAN serial data link

### Door Lock System Controls

The power door lock system can be controlled by any of the following:

• | Automatic door lock function

• | Driver door key cylinder unlock switch activation

• | Driver door key cylinder lock switch activation (export)

• | Power door lock switch activation

• | Remote keyless entry transmission

### Power Door Lock Operation (Front Doors)

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. For further information on the front door latches, refer to Power Door Latch Description and Operation .

### Power Door Lock Operation (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.

### Power Door Lock Switches

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 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.

### Power Door Lock Motors

A power door lock motor is contained within each rear door latch assembly. The right rear door module (RRDM) and left rear door module (LRDM) supplies voltage and ground, through the door lock actuator motor control circuits to its associated door lock actuator motor. The power door lock motors are reversible. The function performed by the lock motor depends on which motor control circuit the voltage is applied to, and which motor control circuit the ground is applied to. To perform a lock function, the module momentarily applies voltage to the door lock motor lock control circuit, and ground to the door lock motor unlock control circuit. To perform a unlock function, the door module reverses polarity and momentarily applies voltage to the door lock motor unlock control circuit, and ground to the door lock motor lock control circuit.

### Power Door Lock Deadbolt Motors (Export)

Export vehicles may be equipped with the deadbolt feature, which includes a reversible deadbolt motor contained within each door latch assembly. Each deadbolt motor is wired to the associated door module through 2 circuits; the deadbolt motor lock control circuit and the door lock motor unlock control circuit. To deadbolt a door, the door module locks the door by momentarily applying voltage to the door lock motor lock control circuit, and ground to the door lock motor unlock control circuit. To complete the deadbolting, the door module then momentarily applies voltage to the deadbolt motor control circuit and ground to the door lock motor unlock control circuit. Once the door is deadbolted, the mechanical lock/unlock linkage within the door lock actuator is physically disconnected so that the door can not be manually unlocked. If the content theft feature is armed at the same time, the interior door lock switches will not operate the locks.

To undeadbolt the door, the door module reverses the polarity, applying battery voltage to the door lock motor unlock control circuit, and ground to the deadbolt motor control circuit.

### Automatic Door Locks

The automatic door lock system provides for the locking or unlocking of one or all of the doors when shifting the transmission. When the vehicle doors are closed with the ignition turned ON and the transmission is shifted out of PARK, all doors will lock. When the vehicle is stopped and the transmission is shifted into PARK, one or all of the doors will unlock.

Operation of the automatic door lock system also depends upon door status information gathered by the associated door module, and examined by the remote control door lock receiver (RCDLR). The system will not operate properly if the RCDLR, which is the door lock master, detects that a vehicle door is open. Each door lock actuator contains a door open switch. Each door open switch receives voltage and ground from the associated door module. When a door is open, the switch closes, voltage flows through the switch, and the door module interprets the flow of voltage as a door open input. The door module sends this information over the GMLAN serial data circuit where it is detected by the RCDLR. If the RCDLR determines that one of the vehicle doors is open, automatic door locking will not be permitted.

The signals supplied by the door open switches are also used by the lighting system in order to determine when to turn the vehicle courtesy lamps ON or OFF. For more information concerning courtesy lamps and the door open switches, refer to Interior Lighting Systems Description and Operation .

It should further be noted that, while each door open switch shares its ground circuit with another switch in the door lock actuator, the door ajar indicator switch, the 2 switches must not be confused when service is required. Unlike the door open switch, the door ajar indicator switch has no affect on door locking. For more information concerning door ajar indicators and the door ajar indicator switches, refer to Door Ajar Indicator Description and Operation .

Automatic door locking is programmed during the manufacturing process, but it can be custom programmed by the operator to fit individual preferences. For information concerning custom programming available and programming instructions, refer to Personalization Description and Operation .

### Central Door Unlock

The vehicle may be equipped with the central door unlock feature. With this feature, all doors can be unlocked from the driver door using the door key. To operate the feature, the door key is inserted into the driver door lock cylinder, turned to the unlock position and held for 3 seconds or longer, or turned to the unlock position twice within 3 seconds. A mechanical linkage rod connects the driver door lock cylinder to the key cylinder unlock switch, which is built into the driver door latch assembly. The key cylinder unlock switch contacts, which are normally open, receive a constant ground via the ground circuit. When the door key is turned to unlock position, the switch contacts close and the DDM detects a switched ground. The DDM sends a message via GMLAN serial data to the RCDLR, indicating the key cylinder unlock switch request. The RCDLR is the master of all lock and unlock operations. If the RCDLR determines that the key cylinder unlock switch request is valid and the conditions are correct for the door modules to perform unlock function, it sends a message via GMLAN serial data back to all door modules to unlock all doors.

### Central Door Lock and Deadbolt (Export)

Some export vehicles may be equipped with the central door lock feature. Some export vehicles may have both the central door lock and deadbolt features. With the center door lock feature, all doors can be locked from the driver door using the door key. With the center door lock and deadbolt feature, all doors can be locked and deadbolted from the driver door using the door key. When the doors have been deadbolted, they cannot be unlocked using the manual lock buttons. If the content theft feature is armed at the same time, the interior door lock switches will not operate the locks. All doors can be undeadbolted using the driver door key, however, only the driver door will be unlocked. After undeadbolting with the door key, the passenger doors can be unlocked manually, or by using either the interior lock switches or the remote function actuator (RFA).

To operate the central door lock feature, the door key is inserted into the driver door lock cylinder and turned to the lock position. This causes all doors to lock immediately. A mechanical linkage rod connects the driver door lock cylinder to the key cylinder lock switch, which is built into the driver door lock actuator. The key cylinder lock switch contacts, which are normally open, receive a constant ground via the ground circuit. When the door key is turned to lock, the switch contacts close and the DDM detects a switched ground signal. The DDM then sends a message via GMLAN serial data to the RCDLR, indicating the key cylinder lock switch request. If the RCDLR determines that the key cylinder lock switch request is valid and the conditions are correct for the door modules to perform lock function, it sends a message via GMLAN serial data back to all door modules to lock all doors.

To operate the deadbolt feature, the door key is inserted into the driver door lock cylinder and turned to the lock position. This causes all doors to lock immediately. If the door key is then held to the Lock position for 3 seconds or longer, or, turned to the Lock position twice within 3 seconds, the DDM interprets the key cylinder lock switch input as a deadbolt request. The DDM sends a message via GMLAN serial data to the RCDLR, indicating the request. If the RCDLR determines that the deadbolt request is valid and the conditions are correct for the door modules to perform deadbolt function, it sends a message via GMLAN serial data back to all door modules to lock all deadbolts. Once the door is deadbolted, all doors are locked and the mechanical lock/unlock linkage within each door lock actuator is physically disconnected so that no door can not be manually unlocked. If the content theft feature is armed at the same time, the interior door lock switches will not operate the locks.

To undeadbolt the doors with the driver door key, the key cylinder unlock switch is used. The key cylinder unlock switch input is interpreted as an undeadbolt request because the vehicles content options are configured for export. The normally open key cylinder unlock switch contacts receive a constant ground source. When the driver door lock cylinder is turned to unlock, the switch contacts close and the DDM detects a switched ground signal. The DDM sends a message via GMLAN serial data to the RCDLR, indicating the switch request. The RCDLR interprets the key cylinder unlock switch request as an undeadbolt request. If all conditions are correct, the RCDLR sends a message back to all door modules to undeadbolt. The driver door will be unlocked and undeadbolted while the passenger doors will be undeadbolted only. The passenger doors can be unlocked manually, or by using either the interior lock switches or the remote function actuator (RFA).

By performing the following actions, the doors can be locked and deadbolted or unlocked and undeadbolted, using the remote function actuator (RFA):

• | Press the RFA lock button once to lock all doors, then press a second time within 3 seconds to deadbolt all doors.

• | Press the RFA unlock button once to undeadbolt and unlock the driver door and undeadbolt all passenger doors, then press a second time within 3 seconds to unlock all passenger doors.