LIN BUS Air Conditioning question. how does it work?
When I go tit nothing electrical worked. I replaced virtually all the ECU modules and the can distributor blocks
now my only major problem if the air conditioning is in limp mode. (it did work for about a day when fiddling with other stuff so I know its probably a short somewhere or loose connection)
It comes up with LIN bus communication error. Does anyone have the exact wiring diagram for this showing the sequence of connection to stepper motors etc please. Also, can someone tell me how it works, would one faulty item knock out all the comms or would it have to be a short. Some of the stepper motors (eg 8 and 9 and a few others) respond perfectly to tests and show their positions in DAS etc, others (those in the picture attached) show 0 as position and I'm assuming thats where the LIN BUS comms have gone down.
I replaced some stepper motors but am still getting LIN BUS comms error for a few motors and the blower regulator (I have tried two different AAC units and two different blower regulators so we can discount hose as cause of the error)
I've spent countless hours on this pulling it apart, tracing wires where I can but I cannot seem to find out what has knocked out these comms.
Any suggestions welcome, I'm at breaking point :-)
That's why flood cars are almost always declared a total loss and scrapped. The problem is, once the initial visible water damage is cleaned up the car can look perfectly normal while it's rotting away internally.

terrymargate, since you have been diagnosing the car, you must have other workshop tools too like the WIS wiring diagrams and functional descriptions. You could start from WIS by ticking group 83 and wiring diagrams and functions, as built configurations and read everything.
The lin bus wiring comes from pe83.40-p-2101sab. Overview: gf83.40-p-3012le.
The lin bus devices are daisy chained, obviously a dead component cannot pass the control signal further to the following device. Have a look at the wiring diagram and check which component is the last one on the chain that responds and then check the next one physically.
terrymargate, since you have been diagnosing the car, you must have other workshop tools too like the WIS wiring diagrams and functional descriptions. You could start from WIS by ticking group 83 and wiring diagrams and functions, as built configurations and read everything.
The lin bus wiring comes from pe83.40-p-2101sab. Overview: gf83.40-p-3012le.
The lin bus devices are daisy chained, obviously a dead component cannot pass the control signal further to the following device. Have a look at the wiring diagram and check which component is the last one on the chain that responds and then check the next one physically.
I was working for a major insurer when Katrina hit and there was a huge problem with flood salvage cars being transported to other states where they were re-titled clean and sold to unsuspecting buyers. It got to the point that we stopped selling the salvage at all and payed instead to have the cars crushed. Think for a moment about the sheer number of electronic components and wiring in a 221 from the dash down, and then imagine soaking it all in salt water for a few days.
As I've told Terry previously, if this is a DIY for his personal use, while it's a bad idea in my opinion, it's not harmful to anyone and I wish him well. He has yet to respond one way or the other. If this car is headed for a clean title and resale I'm not sure we'd want to help.
Last edited by Mike5215; Apr 30, 2014 at 09:09 AM.
Please keep us posted on the progress as I am sure other issues will arise. Do you have any pics of the engine swap?

I was working for a major insurer when Katrina hit and there was a huge problem with flood salvage cars being transported to other states where they were re-titled clean and sold to unsuspecting buyers. It got to the point that we stopped selling the salvage at all and payed instead to have the cars crushed. Think for a moment about the sheer number of electronic components and wiring in a 221 from the dash down, and then imagine soaking it all in salt water for a few days.
As I've told Terry previously, if this is a DIY for his personal use, while it's a bad idea in my opinion, it's not harmful to anyone and I wish him well. He has yet to respond one way or the other. If this car is headed for a clean title and resale I'm not sure we'd want to help.
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I can answer your questions now.
I am keeping this car for myself. its the 5th flood damaged car I have done. 1st was 2009 R350 bought in 2011 and I still have it, it runs prefect; 2nd was 2007 E500, my ex girlfriend bought it when we split. 3rd was CLS500, they would not let me register it in flordia as it had certificate of destruction, so I had to sell it
4th was 2011 E350 convertible, bought in 2012, I sitll have that runs perfectly
and this S550 is my latest purchase. I will keep this one too.
I know you hear horror stories of flooded cars never running right, I guess it depends how much corrosion they suffered and how much effort went into the repair.
I have been lucky with mine. I initially stripped them down, replaced all faulty units and all suspect looking connections, ie CAN distributor blocks. Once finished, they all come up error free in Xentry and usually stay that way. Once I had an error come up with seat heater and the plug on ecu was corroding so I replaced that.
This S550 I have replaced almost every ECU module, it was by far the most flooded car I've bought to date. It has taken months but is almost finished.
As for the engine, I ended up getting one from a CLS550, there was a few minor differences with plugs and the manifolds on the side needed changing with the originals but apart from that it went in fine, used my original ECU so no coding needed and now runs like a dream.
Just have brakes, one light and slipping tranny to fix now, then will be all finished.
I would not recommend this to anyone unless they have shedloads of time on their hands. Its taken countless hours to solve the numerous hurdles but lots of learning on the way. Plus The end product will have cost me around 35k so not that cheap.
Will avoid the salt water ones in future, fresh water is so much easier.
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