Lumbar Support (With RPO Code A45)

MOTORS

The lumbar support system consists of two motors (horizontal and vertical) that operate independently of each other. The lumbar horizontal motor moves the lumbar support in the forward or rearward directions while the lumbar vertical motor moves the lumbar support in the up or down directions. Each motor contains a 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. The memory seat module provides each motor with a soft stop that will actually stop the motor just before its physical end-of-travel. This decreases the stress on each motor. If a motor reaches the end-of-travel due a soft stop and the switch is released and pressed again, the lumbar support will move short distance farther to it's physical travel limit.

Horizontal
When the lumbar switch is operated to move the lumbar support forward, battery positive voltage is applied through the switch contacts and the driver seat lumbar forward switch signal circuit to the MSM. In response to this signal, the MSM applies battery positive voltage through the lumbar motor forward control circuit and ground through the lumbar motor rearward control circuit to the motor. The motor runs to drive the lumbar support forward toward the occupant's back until the switch is released. Moving the lumbar support rearward works similarly to moving the lumbar support forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. The MSM also controls the lumbar horizontal motor during memory recall functions.

Vertical
When the lumbar switch is operated to move the lumbar support up, battery positive voltage is applied through the switch contacts and the driver seat lumbar up switch signal circuit to the MSM. In response to this signal, the MSM applies battery positive voltage through the lumbar motor up control circuit and ground through the lumbar motor down control circuit to the 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 and ground are applied on the opposite circuits causing the motor to run in the opposite direction. The MSM also controls the lumbar vertical motor during memory recall functions.