Memory Seat Circuit Description Oldsmobile w/A43
The IP fuse block PWR STS circuit breaker 3 via CKT 1340 (ORN) supplies battery positive voltage (B+) to power the memory seat/mirror module. Ground for the memory seat/mirror module is provided via CKT 1250 (BLK) to ground G202.
Position Sensors
The MSM uses the position sensors in order to perform the following functions:
| • | Store motor positions |
| • | Return the motors to the stored memory positions |
The MSM provides a 5 volt reference voltage through CKT 788 (GRY) and the reference ground through CKT 782 (BLK) to each of the seat 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 memory seat/mirror module 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 memory seat/mirror module stores the motor positions by recording each position sensor feedback voltage. When you command a memory recall, the memory seat/mirror module moves the motors until the position sensor feedback voltages equal the feedback voltages stored in memory.
For the easy exit function, only seat position sensor feedback voltages are recorded and only the seat motors run.
Manual Movement
The memory seat/mirror module receives the manual movement inputs of the seat from the left seat switch. The IP fuse block CTSY LP/PWR MIR fuse 6A via CKT 640 (ORN) supplies battery positive voltage (B+) to the left seat switch. When a switch is actuated, battery positive voltage (B+) is supplied to the appropriate input of the memory seat/mirror module. When a forward/back, rear height, front height, or recline input is received, the memory seat/mirror module supplies battery positive voltage (B+) to the appropriate motors, and the seat or seatback moves accordingly.
