That is interesting, what is the purpose or benefit of that kill switch? Is it to prevent catastrophic failures due to a bad ISM? So the ISM becomes a wear item instead?

 

makes Merc money - and to get around potential legal ramifications - its a safety related part they wouldn't want going wrong thus endangering your life... there's another in the park brake module, where one could almost agree on the safety angle - and on older cars with SBC (including the maybach) they put one on the brake module too - the SBC tripped so early it was inside warranty so they added 30% for good fun

 

I see. thanks for the explanation.

 

Back to the ECU oil stains, I checked all the cam magnets and sensors. The only one I could tell was seeping oil into the harness is the driver side exhaust cam magnet. The cam magnet plug had oil build up and so did the sacrificial added harness. There was also dried up oil around the cam magnet on the engine block. I've used some CRC QD Electronic Contact Cleaner on the larger ECU harness and when I tap the harness onto a rag there is a good amount of oil coming out. I've done it a few times. Will be replacing the cam magnet as well as the extension harness. I'm debating about spraying the ECU plugs themselves.

 

you need to look at the video of this ECU being repaired on Youtube - and measure the chips as he does (simple) you must open it up - playing with sockets externally will do nothing the damage will be inside - if it has any

as I have said its probably just a failed ISM

https://mbworld.org/forums/s-class-w...ml#post8929983

 

So I started thinking about the suspension side of things and saw @BOTUS mentioned the lever sensor link rod. I read some data with my Foxwell scanner and not sure if anything is wrong, but the voltages for the front two level sensors seem off from their respective ranges and there's a significant ride height difference between the two (But not 100% sure if this all means anything since the vehicle is not raised off the ground).

Level Sensor Data
LF Signal (B28/8): 3.53V (Standing outside), 3.61V (Sitting in Driver seat), 3.57V (Sitting in Passenger seat). Reference: <2.1,3.1>
LF Level: -47mm (Standing outside), -51mm (Sitting in Driver seat), -49mm (Sitting in Passenger seat). Reference: <-3.0,3.0>
RF Signal (B28/9): 1.76 Volts (Standing outside), 1.76V (Sitting in Driver seat). 1.71V (Sitting in Passenger seat). Reference: <1.9,2.9>
RF Level: -41mm (Standing outside), -41mm (Sitting in Driver seat), -45mm(Sitting in Passenger seat). Reference: <-3.0,3.0>
Rear Signal (B28/3): 2.53 Volts (Standing outside, 2.61V (Sitting in Driver seat), 2.59V (Sitting in Passenger seat). Reference: <2.0,3.0>
Rear Level: -11mm (Standing outside), -15mm (Sitting in Passenger seat), -15mm (Sitting in Passenger seat). Reference: <-3.0,3.0>

Acceleration Sensor Data
LF (B24/3): 2529 Millivolts but fluctuates sometimes with 2510
RF (B24/4): 2529 Millivolts but fluctuates constantly with 2510

I can't find where to read the rear acceleration sensor data (B24/6). Doesn't show up under the suspension module live data sets.

Also, I decided to change out all my wheel bolts from those annoying flower shaped chrome cap ones they come with to standard hex bolts. When I jacked up then lowered the front driver side, the car went back to normal level, but when I jacked up then lowered the passenger side, the front suspension both sides sank and sat at a much lower level. The vehicle eventually raised itself up with the airmatic pump running about four or fives times. I did this a second time with the same results. As well, when I was loosening the front driver side lug bolts before raising the car up even, I heard the airmatic compressor start running when trying to break one of them. There was no noise with any of the other sides when replacing the bolts.

 

Well decided to do some digging in the trunk area as well because I noticed whenever the Foxwell would do the full vehicle scan, it would not recognize RFK Backup Camera module and when I'd try to access it manually it would state no communication even though I have a backup camera. I removed the passenger side trunk liner and found this area.

There's all this brownish stains here and also in parts of the middle of the trunk liner. Not sure if this is normal. It also looks like a black burn spot in that corner under that metal plate. I also found a random bolt with a washer sitting there in that fluid under the lower black screw coming out of the body (EDIT: I believe it's a screw for the tail lamp, but I checked both sides and I have three attached for each so this may be one someone dropped back there when doing some work). The driver side where the amp and Sirius module are located had nothing out of the ordinary and was cleaner than the passenger side.

I don't know where this is supposed to go and can't see any others like it down there. I did also notice when removing the passenger side trunk liner that one of the plastic rivets was missing as well as the other two on that side were very loosely pushed in not fully seated. As well, the rubber gasket running along the body of the trunk has become slightly accordion like where the trunk frame slopes down diagonally.

What's that bottom metal plate? I checked the hydraulic unit for the power trunk control and don't seem to be any leaks.

 

the brown gunk is seam sealer - or glue bonding panels together - and is normal
the black corner, I'd suggested is a tiny reaction of the bare aluminium bracket and the seam sealer

that corner only has junk with the joke pump for massage seats and such
a later 221 may only have the budget cam without active lines - the active line module is in the wing above the hifi Amp - is it a plastic RFK - the earlier complex metal camera was not as good and cost three times as much - but the plastic ones whilst working better have far more fake errors in diagnostics - likely some incompetence within Merc's appalling software

the random bolt doesn't look familiar - some animal was trying to fix some bit of garbage these thing are made from and didn't bother to do it correctly - which is normal -

 

Noted about the sealer. There was a hydraulic pump in there I thought was for the trunk enclosed in a plastic container with foam inside. I inspected it and everything looked good. Well interestingly enough, I've always had an issue with the driver side dynamic seat, but the passenger is fine. Both massage functions are fine as well.

I did see a small black box above the hifi amp behind the framing of the vehicle and RFK would be initials for however you pronounced the German word on the module. The camera would work fine when reverse was engaged, but again for some reason it is not able to read it the scanner. I'm not sure which system mine is but it runs on a 5 amp fuse in the rear SAM not a 7.5 one.

I realized the bolt must be for the tail light based on the shaped of it. It looks to be the passenger side tail light was worked on, and someone must have dropped this at some point and replaced it. There is no associated nut for it anywhere so they must've used the same nut.

 

small black box... so do or do you not have active guide lines... ?
AKA they move on screen with the steering wheel - so you can work out on this steering angle I will or won't crash - early cars had one - and it last sold at $2000 - these days all built as std in budget shopping cars on a 10p chip built inside the headunit

I recollect the smaller box - but not sure what it does - maybe you can't access its brain - if its not active what there to care about - the older one has calibration for the movable lines

 

I still don't understand some things.

1. Why was there a battery drain and now all of a sudden after that "short" when trying to remove the driver side floor carpet it's now gone?
2. The fuel gauge before the "short" would show as half tank when ignition on, but once engine was cranked and running, would drop to between quarter and half. After the short, it shows only between quarter and half when both the ignition on and car was running.
3. The ISM is not variant coded for the model vehicle, but shows variant coding for correct transmission.
4. Every time turn ignition on or off the ISM makes a movement noise.
5. The VGS fails adaption at reverse gear stating impluasible and now there is an error in the Xenon, Left module stating reverse signal from ME-SFI implausible.
6. When I clear the VGS code, the transmission shows actual gear and requested gear as Neutral. Before clearing, it shows a signal error. As well, I am able to move the shifter and show D highlighted and transmission module shows D is selected, but gears remain as Neutral. Under steering column module, all shift commands are read properly.

 

did this garage use a load of junk secondhand trash that wasn't suitable ?
is this car and old abandoned wreck you are trying to get going on a shoestring ?

if its a good car I'd take it to a real garage and start over from scratch

 

BenzNinja is the answer IMHO.

 

The car is from a family member. They bought it from an authorized Mercedes dealer here in Los Angeles and put on less than 15k miles in 8 years. It's a very clean car, but seems the previous owner before they purchased it must've used some shoddy body shop to repaint the bumpers and some other work.

Just an update, I ended up towing the car to a local Mercedes dealer towards the end of March. The job was completed and car picked up a couple of days after Easter. It ended up being the ISM as you all suggested. I was very fortunate that another relative of mine with an independent Mercedes shop helped me out with this dealer on the service side (Warranty time rate for this job is 5.4 hours while out of warranty rate is 7 hours and I was able to get it for the warranty time) as well as discount on the part since I have a wholesale account with the dealer. Overall, it ended up costing me almost the same as what a nearby independent shop wanted and now I have 24 months warranty on the part as well as a year of roadside after the job.

Overall, thank you all for all the help on this vehicle. She's a wonder to drive. I hope to keep her for a long time. The only issue after the vehicle was fixed is now the parking brake red error message is always on (Before it would come on when I would engage the brake but then turn off when I would restart the vehicle and put it in drive). Can't seem to get it removed with my Foxwell scanner.

 

Thanks for the update and glad it is fixed, please enjoy the vehicle.

 

Thank you. The silver lining in all this headache was that I discovered one of the camshaft solenoids leaking into the ECU and engine harness. The service advisor told me I was very fortunate to have caught it before it gummed up any other places downstream or fried the ECU. I replaced the defective solenoid with the newest part number 2721560000. As well, I did a lot of cleanup as far as fixing some missing or broken rivets and screws as well as finding those random two bolts rolling around where they should not have been. Now if only I could get this sunroof cover to stop rattling while closed when going over bumps and uneven surfaces.

 

Time to install sacrificial pigtail harnesses. You can usually get those on FCPEuro.

 

 

After a while, when you see oil leaking into the pigtails, replace them, hence why they are called sacrificial pigtails.

 

I currently have my drive train taken apart, and have good access to the ISM. Mine works fine currently, but I know they fail with time and stress. Anyone have a suggestion for someone who remanufactures these? I see lots of new ones on Ebay for $300, but I'm pretty sure these would not work, or at least for not long. It would be a bummer to get my vehicle put back together and have it fail in a month.

 

if you can find a very reputable place that repairs electronics and does loads you could try to repair... but I don't know any - no one seem to discuss repairs like this in the USA

found this to use 20 mins explaining what it does

https://www.automotivetechinfo.com/w...Module-ISM.pdf