What is a Power Lumbar Switch?
Power seats are an option in some cars, trucks, and SUVs that allow the front seats to be adjusted to custom positions or shapes for maximum comfort at the push of a button. Besides forward, backward, up, down, tilt, and headrest adjustments, a power seat may also incorporate extra lumbar support for the lower back to prevent driver fatigue and maintain the natural curvature of the spine. This function is controlled with a switch that is mounted either in the door trim panel or on the side of the seat. In many cases, settings for multiple occupants can be memorized by the seat control module (or by the Body Control Module).
How do Power Lumbar Switches work?
The power lumbar switches communicate with the power seat control module that coordinates the function of the power seat motors. When the switch is pressed, the lower region of the seat's backrest moves forward or backward to support the lower back. The mechanism inside the seat might consist of an inflatable chamber or a motor that moves to change the shape of the seat cushion. In some vehicles, the adjustments are memorized by the seat control module. Power seat adjustments, along with dozens of other functions of the vehicle body (power mirrors, locks, windows, airbags, alarm, et. al.) may be overseen by the Body Control Module.
What are the symptoms of a bad Power Lumbar Switch?
If the power lumbar switch is not working properly, it is likely that the lumbar support will not expand (move forward) or contract (recede backward). Or, the lumbar support might work intermittently. The lumbar support motor or air compressor could be at fault, but the switch is a likely culprit.
Can I drive with a bad Power Lumbar Switch?
A faulty power lumbar switch does not pose an imminent concern with a vehicle. However, improper seat position (relative to the controls and to the airbags) is a safety concern for the driver. If the lumbar support somehow places the driver out of position for safe operation, the problem should be taken care of as soon as possible.