The battery positive voltage (B+) is applied at all times to the left and the right lumbar switches from the trunk compartment fuse block BATT fuse. The battery positive voltage (B+) is applied at all times to the left and the right lumbar vertical/horizontal relay from the left underhood fuse block seats circuit breaker.

Lumbar Up/Down Operation

When the lumbar switch is moved to the UP position, the battery positive voltage (B+) is applied to the up coil in the lumbar vertical relay. The coil energizes. causing the up contact to close. The battery positive voltage (B+) from CKT 742 (RED) is then applied through the relay to CKT 768 (TAN) or (TAN/WHT) (left) or CKT 793 (PNK) or (TAN/WHT) (right) to the lumbar vertical motor.

The ground for the motor is obtained through CKT 767 (PPL) or (PPL/WHT) (left) or CKT 792 (ORN) or (PPL/WHT) (right) lumbar relay along with CKT 850 (BLK) to ground G302. This condition allows the lumbar vertical motor to RUN, moving the lumbar support up to the seat back.

When the lumbar switch is moved to the DOWN position, the circuit operates similarly to the UP mode. The lumbar vertical motor has the polarity reversed. This condition causes the motor to run in the opposite direction, moving the lumbar support down in the seat back.

Lumbar In/Out Operation

The IN/OUT operation is similar to the UP/DOWN operation, except that the horizontal motor moves the lumbar support in or out within the seat back. When the lumbar switch is moved to the OUT position, the battery positive voltage (B+) is applied to the out coil in the lumbar horizontal relay. The coil energizes, causing the out contact to close.

The battery positive voltage (B+) from CKT 742 (RED) is then applied through the relay and the following circuits:

The ground for the motor is obtained through the following circuits:

This condition allows the lumbar horizontal motor to run, moving the lumbar support out toward the driver's back.

When the lumbar switch is moved to the IN position, the circuit operates similarly to the OUT mode, with the exception that the lumbar horizontal motor has the polarity reversed. This reversed polarity causes the motor to run in the opposite direction, moving the lumbar support in away from the driver's back.

The memory lumbar support consists of the memory seat module (MSM). The lumbar motors with a position sensor attached to each motor is also included. The MSM controls the movement of the 2 lumbar motors. All of the motors operate independently of each other.

The rear compartment fuse block BATT fuse through CKT 1840 (ORN) supplies battery positive voltage (B+) in order to power the MSM. The left underhood fuse block SEAT circuit breaker through CKT 742 (RED) provides battery positive voltage (B+) to the MSM which is used in order to run the motors. The ground for the MSM is provided through CKT 850 (BLK) to ground G302.

Motors

The lumbar motors are reversible. The lumbar support is moved in and out by one motor. In order to move the lumbar support in, battery positive voltage (B+) is supplied when the memory seat module (MSM) receives an input in order to run the lumbar horizontal motor away from the driver's back.

When a lumbar out input is received, the MSM supplies power to the same motor. The voltage and the ground are on the opposite motor cavities. The voltage polarity is reversed. The motor runs in the opposite direction, moving the lumbar OUT towards the driver's back. The lumbar vertical motor is powered the same way. When the MSM receives an input from the left lumbar switch, voltage is supplied to the appropriate lumbar motor.

The MSM provides each seat motor with a soft stop. The MSM stops the motor just before the physical end-of-travel for that motor. This condition decreases the stress on each motor. The seat moves a short distance further, to the physical travel limit if a motor reaches the end-of-travel due to a soft stop. This action occurs when the seat is released and activated again.

Position Sensors

The memory seat module (MSM) uses the position seat sensors in order to store the motor positions in memory. The motors return to the stored memory positions. The MSM provides a 5 volt reference voltage through CKT 788 (GRY) and reference ground through CKT 782 (BLK) to each of the lumbar positions.

These sensors are potentiometers that are mounted to each motor's transmission cable. When the cable rotates, the resistance of the potentiometer varies. The feedback voltage is monitored by the MSM or the MMM in order to determine the motor position. The sensor feedback voltages vary from 0.25-4.75 volts.

When a set memory command is executed, the MSM stores the motor positions by recording each position sensor feedback voltage. When a memory recall is commanded, the modules move the motors until all of the position sensor feedback voltages equal the feedback voltages stored in memory.

The lumbar support with massage consists of the lumbar massage module for both the right and left seats. The lumbar massage module controls the movement of the lumbar vertical motor.

The left underhood fuse block SEATS circuit breaker through CKT 742 (RED) supplies battery positive voltage (B+) in order to power both the left and right lumbar massage modules. The ground for the lumbar massage modules is provided through CKT 850 (BLK) to ground G302.

Massage Operation

When the lumbar switch is operated in the UP position an input is supplied to the lumbar massage module from the MSM for the left seat. An input is supplied directly from the lumbar switch to the lumbar massage module for the right seat. The lumbar massage module in turns supplies battery voltage to the lumbar vertical motor. The motor runs in order to drive the lumbar support up until the switch is released. If the switch is operated momentarily in the UP position, the lumbar massage module will cycle the voltage to the lumbar vertical motor. The motor will then drive the lumbar support up and down for 10 minutes or until the lumbar switch is operated in the DOWN position. When the lumbar switch is operated in the DOWN position, the motor runs in order to drive the lumbar support down until the switch is released.