Lumbar Support (Without RPO Code A45)

LUMBAR SUPPORT DESCRIPTION AND OPERATION (WITHOUT RPO CODE A45)

The driver and passenger lumbar support systems each consist of the following components:
- Power Lumbar Switch
- Lumbar Horizontal Motor
- Lumbar Vertical Motor
- The PWR SEAT Circuit Breaker 25 A

Power Lumbar Switch
Battery positive voltage is supplied at all times to each power lumbar switch from the PWR SEAT Circuit Breaker located in the rear fuse block. Both power lumbar switches are grounded via the switch ground circuit and G201. The lumbar switches provide both power and ground to the selected lumbar motors.

Motors
The driver and passenger power seat lumbar systems operate independently of each other. Each motor contains an electronic circuit breaker (PTC) that will reset only after voltage has been removed from the motor. There are two lumbar position motors. These are the lumbar horizontal and the vertical motors. The horizontal motor moves the lumbar forward and rearward and the vertical motor moves the lumbar up and down.

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

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