Power Lumbar Circuit Description w/o A45

Battery positive voltage (B+) is supplied at all times to the lumbar switch from the rear fuse block PWR SEAT circuit breaker.

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

When the lumbar switch is operated to move the lumbar up, battery positive voltage (B+) is applied via the lumbar up switch contacts and the lumbar vertical up control circuit to the lumbar vertical motor. The motor is grounded via the lumbar down switch contacts and the lumbar down control circuit to the 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 (B+) and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Power Lumbar Circuit Description with A45

Battery positive voltage (B+) is supplied at all times to the lumbar switch from the rear fuse block MEM T&T Fuse.

When the lumbar switch is operated to move the lumbar back, battery positive voltage (B+) is applied via the lumbar back switch contacts and the lumbar back circuit to the lumbar back input of the memory seat module (MSM). In response to this input, the MSM supplies battery positive voltage (B+) and ground to the seat lumbar horizontal motor. The motor runs to drive the lumbar back away from the driver's back until the switch is released. When the lumbar switch is operated to move the lumbar forward, battery positive voltage (B+) is applied via the lumbar forward switch contacts and the lumbar forward circuit to the lumbar forward input of the MSM. In response to this input, the MSM supplies battery positive voltage (B+) and ground to the lumbar horizontal motor. The motor runs to drive the lumbar forward toward the driver's back until the switch is released. The MSM also controls the lumbar horizontal motor during memory recall functions.

When the lumbar switch is operated to move the lumbar up, battery positive voltage (B+) is applied via the lumbar up switch contacts and the lumbar up circuit to the lumbar up input of the memory seat module (MSM). In response to this input, the MSM supplies battery positive voltage (B+) and ground to the seat lumbar vertical motor. The motor runs in order to drive the lumbar up until the switch is released. When the lumbar switch is operated in order to move the lumbar down, battery positive voltage (B+) is applied via the lumbar down switch contacts and the lumbar down circuit to the lumbar down input of the MSM. In response to this input, the MSM supplies battery positive voltage (B+) and ground to the lumbar vertical motor. The motor runs to drive the lumbar down until the switch is released. The MSM also controls the seat lumbar vertical motor during memory recall functions.

The memory seat module (MSM) supplies a 5 volt reference voltage and reference ground to the respective lumbar position sensors. The MSM also receives a feedback voltage signal from the lumbar horizontal and vertical position sensors.