When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
[B]W221 massage function driver seat not working - FIXED [/B]
Hi All ,
I have this great 2008 W221 S550 4 Matic Long base wheel with 80,000 km ( about 50,000) . I bought it about 2 years ago and the dynamic seats with the massage function did work at the beginning but I could point out some issues from the first day as the Lumbar inflates and takes 2-3 days to inflate although I did put it to deflate . The second issue was with the cornering function with the seat support , the left side did not always return to it's supposed position (deflate) after driving straight although the right side works perfectly. other thing after 3 months the massage function stopped working , If I put the number of the desired massage it pops to 0 again . went to the authorized dealer , he resets the responsible computer and told me that they need to change the TEMIC module.
Yesterday I had time to test all this crab . took off the back seat cover of both front seats . and switched between the two seat TEMICS as the passenger seat has no issues . the result was the same . driver seat massage wont work .
So I Started checking the air pipes but the seemed to me all OK , although the massage wont work the other functions do work . i started comparing the two seats to discover electrical wires in yellow color all connected together and joined with plastic pipe to hold them together and they all should be directed to ONE TINY YELLOW WIRE that connects back to the computer module with black connector located to the far right side of the TEMIC . The TEMIC has 4 connectors from LEFT to the RIGHT .
1. small black Pin connector .
2. Big black pin connector .
3. white pin connector .
4. small black pin connector - (IT CONNECTS TO HERE)
The problematic wires getting out of the middle of the seat in between the two vents . about 8 yellow tiny wires rapped all together with hard transparent plastic to all join one tiny yellow wire (it seems to be ground ?? ) I took some pictures of the harness but it was late night sorry for the crappy pictures .
The solution was small screw (yes screw ) and piece of wire to connect between all the wires and the disconnected wire . I screwed the screw in the hard plastic where the disconnected small wire should be connected to . then joined the screw with the pieces of the new wire and the disconnected wire. The solution worked . The massage now work perfectly ...
Hi airwolfer, I think I have the same problem, but I want to make sure. When I select message level 2 (or any other level), it goes back to "0" almost immediately. Also, if I change any other setting (i.e. lumbar from 0 to +8), it immediately goes back to 0. I cannot change any seat settings; they all reset to 0. Does this seem like a TEMICS issue similar to what you experienced? Thanks.
How do you take off the back seat cover? I noticed that my left driver side bolster doesn't inflate when I enable dynamic support when making a right turn.
Hi airwolfer, I think I have the same problem, but I want to make sure. When I select message level 2 (or any other level), it goes back to "0" almost immediately. Also, if I change any other setting (i.e. lumbar from 0 to +8), it immediately goes back to 0. I cannot change any seat settings; they all reset to 0. Does this seem like a TEMICS issue similar to what you experienced? Thanks.
I have this exact same problem, would love to fix it!
Most likely you have a seat bladder air leak. A leak in either seat will cause the settings for both seats to fall back to zero. Unfortunately, it can be very expensive to replace an air bladder. I had a passenger seat failure on my CL550 just short of 7 years while still covered by a third party extended warranty. They paid almost $5000 to replace my seat cushion. The replacement of the bladder is complicated due to the airbag and passenger weight sensor in the seat.
Most likely you have a seat bladder air leak. A leak in either seat will cause the settings for both seats to fall back to zero. Unfortunately, it can be very expensive to replace an air bladder. I had a passenger seat failure on my CL550 just short of 7 years while still covered by a third party extended warranty. They paid almost $5000 to replace my seat cushion. The replacement of the bladder is complicated due to the airbag and passenger weight sensor in the seat.
I assume you're talking to the OP and not me? Because my pass. seat works perfectly, all the time. I really think mine is a controller issue and am tempted to order one, swap it out and see what happens
I had the same problem with my 2006 S350 dynamic seat option 409. Symptoms: when you change a setting on the seat the setting goes back to the starting setting. When you read the error messages with an OBD reader it shows 10 problems with the seat. It says:
- Shoulder pads leaking
- Lumbar pads leaking
- Backrest pads leaking
- ecu switched off due to fault
I checked the pump, working fine
I took the driver seat out of the car and took it apart but all bladders seemed intact
I checked the wiring and found the yellow wire was broken. Soldered the wire, erased the error codes and all is working again!
Does anyone have any detailed advice on how to take the back of the CL550 seats off? The video above is for a S550 and the seats are not the same. Thanks!
I have this great 2008 W221 S550 4 Matic Long base wheel with 80,000 km ( about 50,000) . I bought it about 2 years ago and the dynamic seats with the massage function did work at the beginning but I could point out some issues from the first day as the Lumbar inflates and takes 2-3 days to inflate although I did put it to deflate . The second issue was with the cornering function with the seat support , the left side did not always return to it's supposed position (deflate) after driving straight although the right side works perfectly. other thing after 3 months the massage function stopped working , If I put the number of the desired massage it pops to 0 again . went to the authorized dealer , he resets the responsible computer and told me that they need to change the TEMIC module.
Yesterday I had time to test all this crab . took off the back seat cover of both front seats . and switched between the two seat TEMICS as the passenger seat has no issues . the result was the same . driver seat massage wont work .
So I Started checking the air pipes but the seemed to me all OK , although the massage wont work the other functions do work . i started comparing the two seats to discover electrical wires in yellow color all connected together and joined with plastic pipe to hold them together and they all should be directed to ONE TINY YELLOW WIRE that connects back to the computer module with black connector located to the far right side of the TEMIC . The TEMIC has 4 connectors from LEFT to the RIGHT .
1. small black Pin connector .
2. Big black pin connector .
3. white pin connector .
4. small black pin connector - (IT CONNECTS TO HERE)
The problematic wires getting out of the middle of the seat in between the two vents . about 8 yellow tiny wires rapped all together with hard transparent plastic to all join one tiny yellow wire (it seems to be ground ?? ) I took some pictures of the harness but it was late night sorry for the crappy pictures .
The solution was small screw (yes screw ) and piece of wire to connect between all the wires and the disconnected wire . I screwed the screw in the hard plastic where the disconnected small wire should be connected to . then joined the screw with the pieces of the new wire and the disconnected wire. The solution worked . The massage now work perfectly ...
Great tip, Airwolfer!! I jiggled the yellow wires where they all join together in the plastic tube you show and describe and got my lumbar support to work again on my 2008 S550!!
Hoping this tip will help others with Dynamic Seat issues. I’m always looking for answers here to my problems, so I’m paying it forward.
My 2008 40K mile S550 had both seats setting back to zero every time I tested or set them. The SDS said leak in the system.
First leak was the blue line from the pump to the reservoir tank. Line was very hard, brittle, and had a circular split, possibly from heat? Replaced it by cutting 8” of the green line and splicing it in to the connectors. No pics. That seemed too easy.
But there was another leak, and it took a very quiet Sunday morning to listen for the air leaks while running the pump. Found it where the main line comes into the bottom of the passenger (right) seat on the right side of the seat. Line was inside the wire bundle tape, and was again hardened and split (see pics). Hardest part was getting the seat trim off without breaking it.
Old Line would not accept a splice coupling, as it continued to split. Replaced with...Lowe’s drip irrigation line. And it works great. But there were more leaks I could now hear!
The next was behind the Seat Back panel at the T, where the main line splits air to the seat cushion and seat back. There is a tiny ball pressed into a hole in the (weak brittle) plastic tee, and the plastic had split there. I considered an irrigation tee as replacement, but settled on a coat of 5 minute epoxy on the existing tee. Fixed it.
Now I can hear a leak in the seat back...likely from a bladder or another split hose or connector. That one is yet to be found, but the leak is small enough that all seat functions are working, and the pump does not ‘time out’ or overheat. Will share as I fix more fixes for issues.
The leaks continued, and by removing the seat back I found a couple more broken hoses.
The line to the single lumbar bladder is located in the seat back cushion, and is not part of the 'adapter' bladders.
I had to peel up the sticky back black felt on the seat cushion to access the valve and tubing. It was fixed again with irrigation tubing.
Below are pictures of the adapter bladders; the seat back cushion, and the broken line to the lumbar valve in the seat back cushion.
Now I need to work on getting the bladders to inflate/deflate, which I think is due to bad valves.
Stay tuned for more fixes...
Last edited by kbob999; Nov 4, 2022 at 10:36 AM.
Reason: accuracy
Update #2 on the dynamic seat repair, and more DIY fixes!
First off, the seat control modules for the 2007-2009 (?) have a couple different hardware/software versions. 2010 and later has the air valves and control module together as a unit.
The early version module for my '08 (221 870 77 86) is replaced by a later version (221 870 35 93). The later software version is "07/21/01", while the earlier one is "05/32/01".
Note the Production sequence is in the '200000' number range, not the '100000' or earlier versions.
When I replaced my early module version with the later software version, it solved the 'Return to Zero' issue when setting the dynamic seat.
Dynamic is now working!
Early Module Late Module
Next issue, the bladder was not inflating on the right bolster, only the left.
Testing shows the bladder holds air, so it was not a split seam in the bladder. Must be the valve to the bladder.
The valves can fail by not allowing inflation; or not allowing deflation.
I replaced a known good valve from a seat insert (bladders and valves). This valve replacement can be done by removing the seat back and control module, but it is tight.
Valve Labeling on image is S=Shoulder; RB=Right Bolster; LB=Left Bolster; M=Lumbar Middle
Once the defective valve was replaced, the right bladder worked in dynamic mode.
Another successful repair!
Valve Labels
Now on to the passenger seat for the same repairs. Hope this helps others with the same issues.
cooling fans falling off the as new seat base at 40k miles TICK
green pipe with a pin hole in the boot near the pump TICK
module playing up even on later software TICK
module replaced with later hardware and SAME software mine had been updated too seems OK,
most uncomfortable seats on any car I ever owned TICK
'Return to Zero' perhaps is not due to version of the control module, problem likely due to air pipe is crack and lose air pressure for so long therefore seat control module disabled lumbar function to avoid other damage.
you can reactivate it by the Xentry/Das with the below info (line #4 of the screen shot)
updated post above to show the seat module question that popped up today (fourth link)
(fifth link) is the seat cover post from a month back, with lots of PDFs on pulling the seat apart
Thanks Botus for referring me over here. I have what I feel like is a dumb question, which can surely be answered by someone here...
I'm trying to track down various seat problems. I was looking at Ebay for parts, and noticed seat bladders for the lower cushion going all the way across the seat, plus the side bolsters. Do you all have the massage function working on the bottom, as well as the back cushion? My lower cushion side bolsters work, but nothing else on the lower cushion, while the back cushion massage is going. I'm confused by what I'm seeing on Ebay, because the original brochure from 2008 doesn't seem to show bladders on the lower cushion other than the side bolsters. Can anyone clear this up for me? Thanks.
ummm not sure I remember everything - there are I guess a signifiant number of things that are optional on the front seats
electric adjustment - lots of pointless adjustment of the seat squab fore and aft, automatically morphing seat belt points and headrest height - top feature allows the unoccupied seat to slide the headrest down till the leather scuffs making a noise, you adjust a gap to stop it and it returns it back to the scuffing noise straight afterwards - plus electrical adjustments normal cars have
active headrests - bit like a Volvo, except the headrest if far to far away, but moves closer when you crash - would be safer with them popped as the starting point, and move closer when you crash, but they know best
seat memory - buttons on the door, help pump it back to normal when its lost the plot, I press every few months and normally get a quick squeeze somewhere - my mirror on the left passenger side wasn't always staying put - not checked now on the new SAM software - you also get a switchable feature where selecting reverse can give the passenger mirror dip feature if you have the seat memory - nasty feature if you park on slopes as its means the mirror become useless
heated seat - both squab and back rest warm up - mine auto switches from max to a notch down after about 15 mins
vented seat - depending if an early car of a later facelift, draws air from AC outlet on the floor and you get a vague waft of nothingness - early cars the fans self destruct and fall on the carpet - later cars suck the sweat in first, then reverse and give it back (or vice versa)
dynamic seat - air cushions that can actively inflate based on cornering force - nasty late to the party irritation, that just wears out the pump and the air cushions till they fail. It also gives more configuration of the seat. With adjustment on lateral support on the sides of the back rest, and sides of the seat squab.
multi contour backrest - a joke bringing a million points of useless, always in the wrong place lumbar support. And a special extra, to give enhanced shoulder cramps. This is where the shoulder area of the seat has air bags of inflation to move from a minimum of 20% too much shoulder pressure all the way to 200% too much
massage - I think this is just the backrest, quite a good feature - but of random reliability. Runs for 15mins then needs a break.
I want to know what the specs are for the air system itself. What pressure does the system normally run at? Is there a common size for the air lines? Someone had replaced the valves in their seat too; what part number are they? Are all valves the same, in the seats?
Response to nath h: To my knowledge, there are no bladders in the center of the seat cushion, only heating elements.
The center of the seat back has a single lumbar bladder in the seat fabric, and the seat back 'adaptor' has 3 massage bladders.
Response to camplate: The valves for the bladders all look the same, and are interchangeable. They only do 3 things...inflate, deflate, and hold.
Example, the shoulder blade bladders on my seat would inflate, and hold, but not deflate. Very uncomfortable. Zero, or no air, was my favorite setting.
Didn't bother with the valve, just unplugged the 'bleed' hose to them and left them 'dead'. If I had left the wire off the valve it would likely throw an error, so that's why the hose is off.
You need to buy a seat back adaptor on ebay and test/replace valves until they work as expected. That's what I did.
Response to nath h: To my knowledge, there are no bladders in the center of the seat cushion, only heating elements.
The center of the seat back has a single lumbar bladder in the seat fabric, and the seat back 'adaptor' has 3 massage bladders.
Response to camplate: The valves for the bladders all look the same, and are interchangeable. They only do 3 things...inflate, deflate, and hold.
Example, the shoulder blade bladders on my seat would inflate, and hold, but not deflate. Very uncomfortable. Zero, or no air, was my favorite setting.
Didn't bother with the valve, just unplugged the 'bleed' hose to them and left them 'dead'. If I had left the wire off the valve it would likely throw an error, so that's why the hose is off.
You need to buy a seat back adaptor on ebay and test/replace valves until they work as expected. That's what I did.
Yah, I would have thought the same thing as you. I'll paste the Ebay link in below just so people can see what I'm talking about...not sure what cars actually had this part, but apparently not ours. Would have been nice to have massage function in the lower, too.
the normal spec E-class of the same era (I guess without very rare option massage) uses a smaller ID set of pipes and connectors - the hose of the lower class cars actually fits inside the much bigger diameter pipes of high spec w221's
hence the useful repair parts listed in post #17
actually we need to validate them as they look like the small ID pipes
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
) I took some pictures of the harness but it was late night sorry for the crappy pictures . 
