Through Model Year 2011
Power Seats
Power Seat System Description
• Driver seat shown in illustrations. Passenger seat similar.
The power seat system allows the driver and front seat passenger to electrically adjust their seating positions using the power seat switches located on the outboard seat cushion side shield of each front seat.
The available driver and passenger side eight-way power seat includes a six-way adjustable seat cushion track and a two-way power seat back. The power seats can be adjusted up, down, front up, front down, forward, rearward, recliner forward, and recliner rearward. An available two-way power lumbar support can be adjusted forward and rearward. The power seat system is also available with a memory seat option that automatically positions the power seat for two different drivers.
The power seat adjuster (1) contains two reversible motors that are connected to worm-drive gearboxes that move the seat adjusters through screw-type drive units. These motors are the height adjust motor (3) and the front tilt motor (2). The third motor on the power seat adjuster is responsible for the fore and aft movement of the power seat. The fore/aft motor (4) is a reversible motor that is connected through two flex drive cables to a worm-drive gearbox that moves the seat adjuster through a screw-type drive unit. Each motor contains a self-resetting circuit breaker to protect it from overload. Consecutive or frequent resetting of the circuit breakers may damaged the motors.
The power seat adjuster assembly (1) includes the following major components:
• Front Tilt Motor (2) - located on the upper power seat adjuster assembly. Controls the up and down movement of the seat front only. Is available as a service part and if inoperative or damaged can be replaced. Refer to => [ Front Tilt Motor ] Front Tilt Motor.
• Height Adjust Motor (3) - located on the rear of the lower power seat adjuster assembly. Controls the up and down movement of the entire seat. Is available as a service part and if inoperative or damaged can be replaced. Refer to => [ Height Adjust Motor ] Height Adjust Motor.
• Fore/Aft Motor (4) - located on the upper power seat adjuster assembly. Controls the fore and aft movement of the power seat. Is a reversible motor that is connected through two flex drive cables to a worm-drive gearbox that moves the seat adjuster through a screw-type drive unit. Is available as a service kit that includes the flex drive cables and if inoperative or damaged can be replaced. Refer to => [ Forward/Back Motor ] Forward/Back Motor.
The power seat back assembly includes the two following major components:
• Power Lumbar Motor (1) - located on the inboard side of the seat back. Controls the in and out movement of the lumbar support.
• Power Seat Recliner Motor (2) - located on the outboard side of the seat back. Controls the up and down movement of the seat back.
The power lumbar support and power seat recliner cannot be adjusted or repaired and if inoperative or damaged, the entire seat back must be replaced as an assembly. Refer to => [ Seat Back Frame ] Seat Back Frame.
The front power seat(s) is controlled the two following switches located on the outboard seat cushion side shield.
• Power Seat Switch (1) - has paddle-type levers. Vehicles may be equipped with driver only, or driver and passenger power seat switches. One seat switch is used for each front seat. Movement of the seat cushions and backs mimics the action of the switch paddles. The driver power seat switch type (memory or non-memory) can be identified by the color of the switch electrical connector receptacle. Memory switches have a light gray connector receptacle and non-memory have a black receptacle.
• Power Lumbar Switch (2) - is a two way rocker-type switch. Press front of switch and lumbar protrudes out of the seat back. Push rear of switch and lumbar recedes into the seat back.
Memory Seat System Description
An electronic memory seat system is available on certain models. The memory system is able to store and recall all driver side power seat positions, outside mirror positions and power adjustable pedal positions. The system can be set for two different drivers. On vehicles with a factory installed radio connected to the Controller Area Network (CAN) data bus network, the memory system is also able to store and recall up to twelve radio station presets (six AM and six FM), for two drivers. The memory system will also store and recall the last station listened to for each driver, even if it is not one of the twelve preset stations.
Vehicles equipped with the memory seat system can be identified by the memory seat switch (1), located in the driver door panel (9). The memory system will automatically recall all driver side power seat positions, outside mirror positions and power adjustable pedal position settings, when a button of the memory switch is pressed, or when the doors are unlocked using a Remote Keyless Entry (RKE) transmitter (if enabled).
The memory system has an "Easy Entry and /Exit" feature that provides the driver with more room to enter or exit the vehicle by automatically moving the driver seat rearward 55 millimeters (2.1 inches), or to the end of its travel, whichever occurs first. This is also a customer programmable feature of the Electronic Vehicle Information Center (EVIC).
The memory system also has a "Tilt in Reverse" feature that tilts the outside mirrors down a fixed, incremental angle when the vehicle is shifted into REVERSE with the ignition switch in the Run position. This feature provides the customer with a better view of the ground and vehicle in the area of the rear tires when backing up. The mirrors move back to their previous position when the vehicle is shifted out of REVERSE.
The memory system includes the following components:
• Memory Selector Switch - located in the driver door trim panel. Refer to => [ Power Seat Memory Switch ] Power Seat Memory Switch.
• Memory Seat Module (MSM) - located underneath the driver seat. Controls the power drivers seat, power driver mirror and adjustable pedals, when equipped. Refer to => [ Memory Seat Module ] Memory Seat Module.
• Driver Door Module (DDM) - located in the driver door, behind the trim panel.
• Passenger Door Module (PDM) - located in the passenger door, behind the trim panel.
• Hall Effect Sensors - Driver Seat - located in each of the power seat track motors. Are used to provide reference signal to the memory seat module to inform the module of the position of the seat cushion and seat back. Are not serviced separately.
• Hall Effect Sensors - Driver Mirror - located on the outside driver mirror motors. Is used to provide a reference signal to the memory seat module to inform the module of the position of the mirror glass. Are not serviced separately.
• Hall Effect Sensor - Adjustable Pedals - located on the adjustable pedal motor, when equipped. Is used to provide a reference signal to the memory seat module to inform the module of the position of the pedals. Is not serviced separately.
• Sentry Key Remote Entry Module (SKREEM) - located within the Wireless Ignition Node (WIN).
• Remote Keyless Entry (RKE) Transmitter - located within the WIN.
• Radio - located in the instrument panel center stack.
Certain functions and features of the memory system rely upon resources shared with other electronic modules in the vehicle over the Controller Area Network (CAN) data bus. The CAN bus allows the sharing of sensor information. This helps to reduce wire harness complexity, internal controller hardware, and component sensor current loads. At the same time, this system provides increased reliability, enhanced diagnostics, and allows the addition of many new feature capabilities. A scan tool is required for proper diagnostics of the electronic components and the CAN bus.
Power Seat System Operation
The power seat system receives battery current through a fuse in the Totally Integrated Power Module (TIPM), so that the power seats remain operational, regardless of the ignition switch position.
When a power seat switch is actuated, a battery feed and a ground path are applied through the power seat switch contacts to the appropriate motor or motors. The motor and drive unit operate to move the seat in the selected direction until the switch is released, or until the travel limit of the power seat adjuster is reached. When the switch is moved in the opposite direction, the battery feed and ground path to the motor is reversed through the switch contacts. This causes the motor to run in the opposite direction. All three power seat track motors can be serviced separately from the track.
The power recliner motor and mechanism, and the power lumbar support motor and mechanism cannot be adjusted or repaired, and If found inoperative or damaged, the entire seat back must be replaced. Refer to => [ Seat Back Frame ] Seat Back Frame.
Memory Seat System Operation
The Memory Seat Module (MSM) receives battery current through a circuit breaker in the Totally Integrated Power Module (TIPM), so that the power seats remain operational, regardless of the ignition switch position. When the one of the driver memory seat switches is actuated, a resistance signal is sent to the MSM over the Controller Area Network (CAN) data bus. The MSM is responsible for the 12 volt Direct Current (DC) feed and ground path to the driver power seat adjuster motors. The adjuster motors operate to move the driver seat to one of the two preset positions.
The MSM receives memory set and position switch inputs over the CAN bus. The MSM also receives hard wired input from the hall effect sensors, mounted on each of the driver power seat adjuster motors, driver side view mirror motors and the power adjustable pedal motor, when equipped. The programmed software in the MSM allow it to know where the seat, mirror and pedals are located in their designed travel by a pulse count, generated from the hall effect sensors. This way, when a memory seat switch is pressed, the MSM will power the adjuster motors until the correct preset seat position is achieved. The MSM will prevent the seat memory recall function from being initiated if the transmission gear selector lever is not in the Park position, or if the vehicle is moving, or if the driver seat belt is latched. These inputs are also monitored over the CAN bus by the MSM.
A memory setting is saved by pressing the "set" button, then pressing either the memory "1" or "2" button within 5 seconds of pressing the "set" button.
A memory setting is recalled by pressing either the memory "1" or "2" button, or by pressing the unlock button on a "linked" Remote Keyless Entry (RKE) transmitter (also known as the key fob).
The Electronic Vehicle Information Center (EVIC) serves as the user interface for the memory seat system. It displays memory system status messages and provides the user with the means for enabling and disabling the customer programmable features on the vehicle.