Lumbar Supports S320
 

Both lumbar supports will fill up with air and after about 3 minutes both will deflate at the same time. You'll then here the pump in the rear seat and the lumbar supports in both seats will pump with air and are again fine until 3 - 5 minutes later, when both will lose air at the same time. This will continue until the pump deactivates. In order to reactivate this cycle, I pull one of the fuses in the trunk for a minute and put it back in and cycle starts all over again. I stop the cycle by not touching the fuse so I wont burn up the pump motor.

does anyone have a clue as to what might be wrong?

gfdent

It sounds like a Vaccuum Leak in the Sysyem!
Use a Hand Tester to test the Seat bladders at the Line connection under the seat to see if its a leak in the system or in the Bladders...Could be a Connection leak or a defective bladder
and or the Pump..You MUST trouble shoot the system

Do you mean test with my hands to feel if there is a leak, or is there a special tester? and should I pull up the carpet in the back floor area. Not sure where the air lines run after they leave the air pump under right rear seat. do you know where these line go after they exit the pump ?

gfdent

You Will Need a Vaccuum tester (Hand Held) NOT Your hands. Could be a Seat bladder/Connection/Pump or line leak
I Would start at the seats and work your way back to the pump
follow the lines..