Hi,
Well my passenger front seat shoulder bladder was getting larger. I turn the car off and it would not deflate to a zero state. Over time the bladder became larger.
I booked in to see the local MB agency to connect to the computer however they could not fit me in within 7 days.
On the friday before the monday I had a client in the back seat and the front seat bladder exploded in the front seat......
I took it to MB and they could not truly identify the problem at this point as the bladder was gone.
Their software could not inflate or deflate the should cushion it did not have the ability to identify the shoulder cushion...

?? does anyone know in the USA if the software can identify each section of the seat like the command system does for the driver . If so what is the name or version of system is being used.

?? Correct me if I am wrong but for $200 they passed it to a junior tech and the voltage that came up on the report was 11.40V which means that they don't know what they are doing as the car has drained under 12V. I would assume some circuitry would require a voltage above that 12V rail.
?? Could that low voltage damage modules or give faulty module readouts ?

The other problem was the side airbags that grab you as you go around a corner they worked intermittently as does the back massager function
There are NO LEAKS.

I have ordered 2 x new control modules one for each seat however that is most likely not the issue as up until the blowout of the seat all functions worked intermittently....which implies an electronic signal is being sent but not received.

It appears to be a physical device rather than electronics which would be a valve actuator of some description to open or close and let air in or out and is spotted on the below as PY00317...
But you can NOT buy that part you have to buy the whole seat insert for 800USD.....A2219102275 which is a whole seat insert with new bladders and these actuators........
?? Does anyone know anything about the PY003217 modules




Grant - Electronics Engineer - Australia

 

I've been dealing with an issue in my pneumatic seats since I purchased the car. They got to where they quit working except for very intermittently which got solved by replacing the voice control module.....

Now they work... still no memory functions for seats... The bolsters that are supposed to inflate in turns... bladder in right side of driver's seat inflates to the size of a football, wants to stay that size.... works very intermittently + when it is hot out the shoulder bladders just up and decide they are going to be a pair of baseballs behind my shoulders until I drive it for a while whilst attempting to inflate to 1 and back to zero. Eventually it will deflate them. Makes me want to unplug the PSE in the trunk. Sure behaves as though there is a MAP sensor for each of the bladders and that they get confused when hot.

Thus; I'm interested in how this gets solved.

 

At this stage I am not sure if dealer at low volts has damaged control units... so the three faults that have now popped up are to replace the door unit and two seat control units... may be a waste of money...BUT at 2008 model I dont mind to replace with NEW as that gear is 12 years old.

I am very positive it is the actuator units in the inserts....... mechanical items always have a poorer life cycle compared to the elctronics...I am NOT sure on whether those little plastic parts can be replaced individually and no reply on that matter,,,,, so it will have to be a seat insert new replacement...ouch, which over here is $3,000 AUD per insert x 2 .... plus labour....

 

Usually the actual plastic bladder that inflates will burst.

If any of the seat air functions work, the pump is fine. The valves rarely fail. The plastic bags are far more common of a failure point. The whole lumbar/bolster unit is usually replaced as one piece by the dealer anyway.

 

OK so I replaced the electronic control modules and it made no difference to the seat. The drivers side is exhibiting issues not with not releasing the air, just keeping on inflating until the bladder will no doubt burst. I would think this was a mechanical valve failure rather than a software corruption...but it will explode before I find out......

 

Anyone find resolution here?

 

Unfortunately no........and my other seat is playing up. The Mercedes dealer was unable to identify the problem, I bought seat modules to replace the existing and that did not work after coding... so back to the original ones...I don't think their software can check the individual operation of each part of the seat. I am not prepared to buy the inserts and have them fit at great expense for this problem to reoccur. The voltages on the physical components in the inserts are higher on the newer model S-class and I have no idea whether this has fixed problems on the future models. I am using a professional mechanic that is not the dealer as he knows considerably more and can be totally trusted. I am just letting this be the "ONE THING" that is wrong and I am not going to fix.

 

By the way ....yes the LHS passenger bladder did explode as the dealer could not fit me in for servicing of this on the star system to reset it to a normal or zero position. It just kept slightly inflating until a loud bang ...the leather is stretched slightly in that region...not too noticeable