Lumbar Operation

WARNING: This page is about a different car, the 2003 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

Both lumbar motors are reversible. For example, when the lumbar switch is operated to move the lumbar support forward, battery positive voltage is applied through the lumbar switch contacts and the lumbar forward relay control circuit. The relay coil then energizes, causing the forward relay contacts to close to battery positive voltage. Battery positive voltage is then applied through the lumbar motor forward control circuit to the lumbar horizontal motor. The motor is grounded through the lumbar motor rearward control circuit and the rearward relay contacts. The motor then 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 lumbar vertical motor is also powered this way.