Lumbar Support Description and Operation (Without RPO Code A45)

LUMBAR SUPPORT DESCRIPTION AND OPERATION (W/O A45)

LUMBAR SUPPORT COMPONENTS
The driver and passenger seat lumbar support systems each consist of the following components:
- Lumbar Switch
- Lumbar Horizontal Motor
- Lumbar Vertical Motor
- PWR SEAT Circuit Breaker 30 A
- RR LUM/ANT Fuse 20 A

LUMBAR SWITCH
Battery positive voltage (B+) is supplied at all times to the driver and passenger seat lumbar switches from the PWR SEAT Circuit Breaker located in the rear fuse block. Battery positive voltage (B+) is supplied at all times to the LR and RR passenger lumbar switches from the RR LUM/ANT Fuse located in the rear fuse block. All four lumbar switches are grounded through the switch ground circuits and G 302. The lumbar switches provide both power and ground to the selected lumbar motors.

MOTORS
The lumbar support system consists of two lumbar motors (horizontal and vertical) that 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. The lumbar horizontal motor moves the lumbar support forward and rearward and the lumbar vertical motor moves the lumbar support up and down.

HORIZONTAL
When the lumbar switch is operated to move the lumbar support rearward, battery positive voltage (B+) is applied through the lumbar rearward switch contacts and the lumbar motor rearward control circuit to the lumbar horizontal motor. The motor is grounded through the lumbar forward switch contacts and the lumbar motor forward control circuit to the horizontal motor. The motor runs to drive the lumbar support rearward away from the occupant's back until the switch is released. Moving the lumbar support forward works similarly to moving the lumbar support rearward, except that battery positive voltage (B+) and ground are applied on opposite circuits causing the motor to run in the opposite direction.

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