Dynamic seats/pneumatic pump issue - troubleshooting help
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w211 e500
Dynamic seats/pneumatic pump issue - troubleshooting help
Hello, I have a 2005 e500
My issue is that my dynamic seats don't work properly. When I first start the car, the pump in the trunk fills the reservoir, and I can use the seat adjustments until the reservoir empties. When it goes below a certain PSI, the pump should kick in to fill it again but it doesn't.
if I turn on dynamic seats and use the adjustments (when the reservoir has pressure/psi), it only moves in short bursts. As well, when I'm driving, only the right side will work SOMETIMES, and the left NEVER.
Troubleshooting:
I checked all airlines and bladders in both seats: NO LEAKS
I checked airlines connected to pump and the reservoir: NO LEAKS
All fuses are good.
Not sure about relays, don't think that there is any for the dynamic seats.
I took apart pump and I didn't see any melting nipples or any damage from heat or any electrical damage either.
There are 4 wires that run to the pump, I'm assuming 12v, ground, and the two smaller ones are the ones that turn it off and on when the reservoir is low. I figured there was a sensor or something so I traced those 2 small wires into the BCM (Battery control module)
I removed the BCM, opened it up, didn't see any obvious electrical damage. Wires up to the connector are good.
The pump does turn on when I start the vehicle or click the unlock button on my key and it will fill up the reservoir. Just when it gets empty, the pump will not turn on to refill.
I did clean connectors on both batteries and the BCM because they were somewhat corroded, made no difference.
Any ideas?
( I made a second post because for some reason I can't load other one on my phone, it won't let me see anything or reply or edit or anything)
My issue is that my dynamic seats don't work properly. When I first start the car, the pump in the trunk fills the reservoir, and I can use the seat adjustments until the reservoir empties. When it goes below a certain PSI, the pump should kick in to fill it again but it doesn't.
if I turn on dynamic seats and use the adjustments (when the reservoir has pressure/psi), it only moves in short bursts. As well, when I'm driving, only the right side will work SOMETIMES, and the left NEVER.
Troubleshooting:
I checked all airlines and bladders in both seats: NO LEAKS
I checked airlines connected to pump and the reservoir: NO LEAKS
All fuses are good.
Not sure about relays, don't think that there is any for the dynamic seats.
I took apart pump and I didn't see any melting nipples or any damage from heat or any electrical damage either.
There are 4 wires that run to the pump, I'm assuming 12v, ground, and the two smaller ones are the ones that turn it off and on when the reservoir is low. I figured there was a sensor or something so I traced those 2 small wires into the BCM (Battery control module)
I removed the BCM, opened it up, didn't see any obvious electrical damage. Wires up to the connector are good.
The pump does turn on when I start the vehicle or click the unlock button on my key and it will fill up the reservoir. Just when it gets empty, the pump will not turn on to refill.
I did clean connectors on both batteries and the BCM because they were somewhat corroded, made no difference.
Any ideas?
( I made a second post because for some reason I can't load other one on my phone, it won't let me see anything or reply or edit or anything)
Last edited by adoomie; Apr 10, 2020 at 12:09 AM.
