A45 is the option code for the following components:
The memory seat system consists of the following components:
• | The memory seat module (MSM) |
All of the motors, except the belt tower motor, have position sensors.
The MSM controls the movement of the 5 seat position motors. All of
the motors operate independently of each other.
The rear fuse block MEM/RFA fuse supplies battery positive voltage (B+)
to the MSM through CKT 2040 (ORN). The rear fuse block PWR SEAT
circuit breaker provides battery positive voltage (B+) to the MSM through
CKT 1340 (ORN). Power from CKT 1340 (ORN) operates the
seat motors. The MSM grounds through CKT 450 (BLK) to G201.
Motors
The following 3 motors move the position of the seat:
• | The rear vertical motor |
• | The front vertical motor |
Both vertical motors operate simultaneously when the left seat switch
signals the entire seat to move up or down. The recline motor moves the angle
of the seatback. The belt tower motor moves the height of the belt
tower.
All of the motors are reversible. For example, one motor moves the seat
both forward and backward. When the seat switch sends a signal to the MSM
to move the seat forward, the MSM supplies the following items in order
to operate the motor and move the seat forward:
• | Battery positive voltage (B+) |
When the seat switch sends a signal to the MSM to move the seat backward,
the MSM supplies power to the same motor. The MSM switches the voltage and
the ground to the opposite cavities on the motor connector. The voltage
polarity reverses and the motor then operates in the opposite direction.
All of the following motors operate in an identical manner:
• | The power lumbar motors |
• | The power mirror motors |
The MSM provides each seat motor with a soft stop. The module stops
the motor just before the end of physical travel for the seat. The soft stop
decreases the stress on each motor. The seat will move a short distance
farther to the physical travel limit under the following conditions:
• | The module stops the motor using a soft stop. |
• | The seat switch releases. |
• | The seat switch activates again. |
Position Sensors
The MSM uses the position sensors in order to perform the following
functions:
• | Store the motor positions. |
• | Return the motors to the stored memory positions. |
The belt tower motor does not have a position sensor. The MSM provides
a 5 volt reference voltage through CKT 788 (GRY) and the reference
ground through CKT 782 (BLK) to each of the following components:
• | The seat position sensors |
• | The lumbar position sensors |
The position sensors are potentiometers mounted to the transmission
cable of each motor. When the cable rotates, the resistance of the potentiometer
varies. The MSM monitors the feedback voltage of the potentiometer in
order to determine the position of the motor. The sensor feedback voltages
vary from 0.25 volts to 4.75 volts. When you execute a
set memory command, the MSM records each position feedback sensor in
order to store the motor positions. When you execute the recall memory
command, the MSM moves the motors until the feedback voltages of all
of the position sensors equal the feedback voltages stored in memory.
For the easy exit function, the MSM records only the seat position
sensor feedback voltages. For the easy exit function, only the seat motors
operate. The lumbar support is not involved.
Manual Movement
The MSM receives the manual movement signals of the seat from the left
seat switch. When the MSM receives one of the following signals, the MSM supplies
battery positive voltage (B+) to the appropriate motor(s) and the seat
moves accordingly:
• | A front vertical signal |
Memory Functions
The left front power window switch receives the signals from the memory
function switch. The left front power window switch then sends a message through
the simple bus interface (SBI) to the driver door module (DDM). The
message indicates that the switch received a memory function signal.
The DDM then sends a message to the MSM through the class 2 serial
data line. The MSM records the current lumbar support positions for
2 different drivers. In order to record the current seat positions,
press and hold one of the following buttons for 3 seconds:
A chime will sound in order to acknowledge the signal. When the MSM
receives a memory set message, the MSM records the feedback voltages from
the following sensors for the appropriate driver:
• | The 3 seat position sensors |
• | The recline position sensor |
When you press one of the memory buttons, a single chime sounds in order
to acknowledge the signal. From the memory buttons, the MSM receives the
memory recall message. The MSM then applies battery positive voltage
(B+) to the seat motors until the position sensor feedback voltages
equal the feedback voltages stored in memory for the appropriate driver.
Recall Personalization
When you use a keyless entry transmitter in order to unlock the doors
of the vehicle, the remote function actuator (RFA) module communicates the
following information to the MSM through a class 2 message:
• | The driver that performed the command |
The following 3 personalized recall options are available when
the MSM receives an unlock command:
• | Recall immediately upon receipt of the RFA message. |
• | Recall when the MSM receives a key-in message. |
• | Do not recall upon receipt of an RFA message (recall functions
perform only from the memory switches). |
Memory Inhibit/Enable
The MSM receives the ignition signals from the IP fuse block IGN SEN
Fuse through CKT 241 (BRN). The MSM receives the gear selector position
through class 2 messages. When the ignition switch is in the
OFF position, the following functions are allowed:
• | The memory record function |
• | The memory recall function |
• | The personalization recall function |
• | The exit recall function |
The personalization recall function deactivates under the following
conditions:
• | The ignition switch is in the ON position. |
• | The gear selector is in the PARK position. |
All other memory functions remain operative.
Memory record remains active under the following conditions:
• | The ignition switch is in the ON position. |
• | The gear selector is out of the PARK position. |
All other memory functions deactivate.