Seats: Description and Operation

Power Seats System Description and Operation

The driver and passenger power seat systems each consist of the following components:

* Seat adjuster switch

* Seat horizontal motor

* Seat front vertical motor

* Seat rear vertical motor

* Seat recline motor

Seat Adjuster Switch

The seat adjuster switches provide both power and ground to the selected seat motors. Battery positive voltage is supplied at all times to the driver and passenger seat adjuster switches through a circuit that is breaker located in the I/P fuse block. The driver and passenger seat adjuster switches receive ground through the switch ground circuit and ground connection.

Seat Motors

All of the seat motors operate independently of each other. Each motor contains an electronic circuit breaker (PTC) that opens in the event of a circuit overload and will reset only after voltage has been removed from the circuit. There are four seat position motors. These are the horizontal motor, front vertical motor, rear vertical motor, and the seat back recline motor. The seat horizontal motor moves the entire seat forward and rearward. The seat front vertical motor moves the front of the seat cushion up and down. The seat rear vertical motor does not move the rear of the seat cushion up and down, it actually moves the entire seat up and down with a forward and rearward movement added to it. The seat back recline motor moves the angle of the seat back forward or rearward.

Horizontal

When the seat switch is operated to move the entire seat forward, battery positive voltage is applied through the switch contacts and the horizontal motor forward control circuit to the motor. The motor is grounded through the horizontal motor rearward switch contacts and the horizontal motor rearward control circuit to the motor. The motor runs in order to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Front Vertical

When the seat switch is operated to tilt the front of the seat cushion up, battery positive voltage is applied through the switch contacts and the front vertical motor up control circuit to the motor. The motor is grounded through the down switch contacts and the front vertical motor down control circuit to the motor. The motor runs in order to drive the front of the seat cushion up until the switch is released. Tilting the front of the seat cushion down works similarly to tilting the front of the seat cushion up, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Rear Vertical

When the seat switch is operated to move the entire seat up, battery positive voltage is applied through the switch contacts and the rear vertical motor up control circuit to the rear vertical motor. The motor is grounded through the down switch contacts and the rear vertical motor down control circuit to the motor. The motor runs in order to drive the entire seat up and forward until the switch is released. lowering the seat down works similarly to moving the entire seat up, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Recline

The seat recline motor includes an inhibit switch that is external to the motor. The purpose of the switch is to keep the internal recliner gears from being damaged when it is in operation. The inhibit switch is pigtailed off the motor and is serviced only as part of the recline motor as an assembly. The switch contacts are closed when the seat back is in the upright locked position and open when the seat back is manually dumped forward by the easy-entry mechanism. When the inhibit switch contacts are open, the seat recline function will be inoperative.

When the seat recline switch is operated to move the seat back forward, battery positive voltage is applied through the switch contacts and the recline motor forward control circuit to the motor. The motor is grounded through the rearward switch contacts and the recline motor rearward control circuit to the motor. The motor runs in order to move the seat back forward until the switch is released. Moving the seat back rearward works similarly to moving the seat back forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction.