GM Service Manual Online
For 1990-2009 cars only

Power Sliding Door (PSD) System Components

The power sliding door (PSD) system consists of the following components:

    • Left power sliding door module (PSDM), also known as the left rear side door actuator control module--Class 2 module that controls the unlatching, opening, and closing of the left sliding door. Receives, interprets, and stores door position data, requires initialization, and is capable of service programming system (SPS) programming
    • Right PSDM, also known as the right rear side door actuator control module--Class 2 module that controls the unlatching, opening, and closing of the right sliding door. Receives, interprets, and stores door position data, requires initialization, and is capable of SPS programming
    • Body control module (BCM)--Supplies both the left and right PSDMs with a switched 12-volt signal when the vehicle is in Park
    • Left PSD motor and clutch assembly--Electromagnetic clutch that couples the drive motor to the cable drive mechanism
    • Right PSD motor and clutch assembly--Electromagnetic clutch that couples the drive motor to the cable drive mechanism
    • Left PSD detent switch--Signals the left PSDM when the door striker has entered or exited the door latch
    • Right PSD detent switch--Signals the right PSDM when the door striker has entered or exited the door latch
    • Left PSD position sensors--Hall effect sensors supplied a 5-volt and low reference by the left PSDM. Used to determine position, direction and rate of travel of the sliding door
    • Right PSD position sensors--Hall effect sensors supplied a 5-volt and low reference by the right PSDM. Used to determine position, direction and rate of travel of the sliding door
    • Left PSD unlatch actuator--Electrical latch used to release the sliding door
    • Right PSD unlatch actuator--Electrical latch used to release the sliding door
    • Left PSD on/off switch, also known as the left PSD enable/disable switch--Latching style switch that provides a switched ground to the PSDM to enable the left sliding door
    • Right PSD on/off switch, also known as the right PSD enable/disable switch--Latching style switch that provides a switched ground to the PSDM to enable the right sliding door
    • Left PSD overhead console open/close switch--Momentary switch that provides a switch ground signal to the PSDM for both open and close functions
    • Right PSD overhead console open/close switch--Momentary switch that provides a switch ground signal to the PSDM for both open and close functions
    • Left PSD B pillar open/close switch--Momentary switch that provides a switch ground signal to the PSDM for both open and close functions
    • Right PSD B pillar open/close switch--Momentary switch that provides a switch ground signal to the PSDM for both open and close functions
    • PSD 15-amp fuse--Located in the instrument panel (I/P) fuse block, is hot at all times, and provides module logic power
    • LH - PSD 40-amp fuse--Located in the I/P fuse block, is hot at all times, and provides high current supply for the left sliding door motor and clutch
    • RH - PSD 40-amp fuse--Located in the I/P fuse block, is hot at all times, and provides high current supply for the right sliding door motor and clutch

Power Sliding Door (PSD) System Controls

The power sliding door (PSD) can be operated by any of the following means:

    • Manual operation of the PSD, using either the exterior or interior PSD handle.
    • A keyless entry transmission
    • The right or left PSD overhead console open/close switches, provided that the PSD enable switches are active.
    • The right or left PSD B-pillar open/close switches, provided that the PSD enable switches are active.

The PSD will operate from the B-pillar and overhead console open/close switches only when the PSD system enable switch in the overhead console is active. At anytime during PSD operation, the enable switch may be activated to the off position and the system will quit any function in process. The PSD will not open unless the vehicle gear selector is in the park position and the PSD is unlocked. When the sliding door security lock is in the locked position the PSD will not open from the inside. However the PSD close function will operate when the vehicle is not in park to allow the door to close. The momentum of the vehicle moving forward adds resistance to the door closing operation. When the power sliding door control module (PSDM) determines the vehicle is moving forward while closing the door, current flow through the actuator motor is increased instead of being reversed. The sliding door alarm will sound repeated short tones whenever the PSD system is enabled and the door is open while the vehicle is out of park.

When the PSD system is enabled and manual operation of the PSD is detected, the PSDM activates the power assist feature. When the power assist is activated the PSD will continue to open or close without any further manual effort.

The PSD may be operated using the remote keyless entry (RKE) system, regardless of the status of the system enable switch. The keyless entry transmitter will have one OPEN/CLOSE button with a van symbol on it for each PSD.

Power Sliding Door (PSD) System Description

Important: The power sliding door (PSD) system can operate correctly only if the sliding doors are in proper mechanical condition. Any mechanical problems will affect PSD operation and must be repaired before attempting to diagnose the system. Manually open and close the PSD to determine if the door moves smoothly and without excessive resistance or binding. The PSD must also latch and unlatch without the use of excessive force. At any time during PSD open or close operation, excessive resistance to the door movement will cause the PSD to stop and reverse the direction of travel.

Power Sliding Door Module (PSDM)

The power sliding door module (PSDM) monitors the door position at all times including during manual operation. If the PSDM loses battery voltage or ground, the Rear Side Door Actuator Control Module Programming and Setup procedure must be performed in order for the PSDM to correctly determine the door position.

PSD Motor and Clutch

The PSDM supplies the power and ground to operate the PSD motor and clutch. The direction of the motor rotation is determined by which of the motor control circuits is supplied 12 volts and which is grounded. The PSDM varies the current flow through the motor ground circuit to control the speed of the motor as necessary. The clutch enables the PSD to be operated manually when de-energized, or by the motor when energized.

PSD Detent Switch

The PSDM uses the PSD detent switch to determine when the door is latched, ajar, or open. The detent switch is part of the sliding door lock assembly. The detent switch signal circuit is supplied 12 volts through a resistor within the module. The signal circuit is briefly pulled to ground as the door moves from latched to ajar while opening, or from ajar to latched while closing. The detent switch signal and ground circuits, along with all other PSD circuits, are connected to the body harness through the sliding door contact plungers and B-Pillar contact pads when the plungers and pads are in contact with one another.

PSD Unlatch Actuator

The unlatch actuator is responsible for latching and unlatching the PSD. When latched, the PSD is in the fully closed and tightly sealed position. When unlatched, the PSD has been released from the tightly closed position to an ajar position, from which it can then be opened. The unlatch actuator is controlled by the PSDM. When the PSD is closed and a PSD switch or keyless entry transmitter PSD button is pressed, the PSDM interprets this input as a sliding door unlatch request. In response, the PSDM momentarily supplies battery positive voltage through the sliding door latch motor control circuit to the unlatch actuator. The unlatch actuator is grounded through splice S848 to body ground G302. Once the unlatch actuator has released the PSD to the ajar position, the PSD can then be partially or fully opened. When the PSD is operated to the closed position, the unlatch actuator is mechanically moved back to the latched position. As the actuator becomes latched, it mechanically cinches the PSD to the tightly closed and sealed position. When the PSD is manually opened or closed, the latch or unlatch function of the actuator occurs manually as the PSD is opened or closed.

PSD Unlock Actuator

As previously stated, the power sliding doors must be unlocked before they can be operated. However, if the PSD button of the keyless entry transmitter is pressed once while the PSD is locked, the body control module (BCM) automatically powers the unlock actuator to unlock the door before the PSDM commands the door to unlatch and move. Both the unlocking and open/close function of the PSD is initiated from one press of the button. Lock/unlock actuators for all doors, including the power sliding doors, are described together in the power door locks description and operation. For a more detailed description of these actuators, refer to Power Door Locks Description and Operation .

PSD Position Sensor

The PSDM uses position sensors to monitor the sliding door position at all times. The position sensors require a 5-volt reference and reference return from the PSDM. There are also 2 signal circuits from each position sensor to each PSDM. The sensors send pulses through both signal circuits to the PSDM whenever the sliding door is in motion. The sensor pulses allow the PSDM to calculate the position of the sliding door at all times.