Has anyone had to replace their ISM for a transmission shifting problem with message “ Drive to workshop without changing gear”? I’ve heard you can’t DIY and wondering about a price. Thanks in advance before I call the dealer.

 

i had it done on my merc. If you want to do that yourself, to replace it, you have to have ISM which is reset, because used ones are paired up to the previous car and it would not work with any other. After fitting the reset unit you will have to go through the learning process, using Star Diagnosis only. If you have all that it is quite simple to do.

Initially i wanted to do that with mercedes dealership, but they are replacing the part with a new only and were quoting me some ridiculous moneys, dont remember now what the price was exactly, over a thousand GBP.

So i found some company which is selling the refurbished ones with part exchange, or refurbishing yours. I bought the refurbished one from them for under 400GBP, fitted it, works well so far (done that 3 years back). You will definitely find some company which is refurbishing them in US as well.

Oh, and another thing, important one: if this error is coming up on the dash, it is not necessary the ISM fault. It can be the ignition module (IZS, i guess), under voltage to this module, or that it is faulty or it could be something else. If i was you, i first would investigate all other probable reasons, you might end up having to just clean the power lines connections. For troubleshooting all of that, you will need the Star Diagnosis scanner.

 

As virgisr said, the codes must be read in all modules. If you do not have a scanner, get one.
The ICM has been declared a Theft Relevant Part and that means that you cannot buy it. Only a dealer or approved mechanic shop may purchase and install it. How they legally got away with this is beyond me, but they did. They cornered the market.

 

Thank you for that info. Quite an issue there. Sounding like not worth the cost of the vehicle.

 

Thank you sir. I did become aware of the purchasing problem. They did corner the market and make it a very expensive fix. I have a real dilemma now as a 2006 ML500 with 200k+ miles may not be worth it. Thanks again.

 

Then what are you going to do with it, junk it, sell it? Why don't you get your own scanner and find out exactly what your problem is or find someone who has a scanner and read the codes?


Explain what your problem is.

 

I think I will try to clean it first. It seems to respond after I wash the car and spray underneath the vehicle. I’m not a real DIY person so buying a lot of different equipment is not feasible to me. I should go on social media and possibly find a person with a scanner in my area. That would be another step. I have found an ISM but having it programmed may be difficult outside a dealer. Thank you for your interest and any other thoughts are appreciated. Dan S

 

Hi

Just getting used ISM from another car and trying to code it to your car is not going to work. It has to be reset first. That can not be done via the star scanner. Some refurbishment company who is refurbishing them would be able to reset it.

Just to let you know so you dont waste your money on a used unit which is not reset.

Also I would check the main battery connectors as well. If they are oxidized and not giving enough voltage on the ignition, that might affect the ignition module feed, which if not functioning right, gives same message, of can not shift go to workshop message. And of course, check the connector on this module itself (ignition module).

Hope that helps.

 

Yes. Very helpful. The ISM I found the seller said they would reset it if needed. Is it possible to then recalibrate it yourself and what equipment do you need. I hope that cleaning all the connections might fix it because as mentioned previously it seems to not show the message when I spray off underneath the vehicle. Thanks again. I’m embarrassed to say I don’t have the finances for a dealer repair if it is as expensive as mentioned.

 

You will need to use Star Diagnosis scanner to perform the ISM learning procedure, its the mercedes specific car diagnostics scanner, very useful tool if you own a mercedes. If you have access under your car, definitely check the ISM connection as well and clean it if here is any moisture in it, oxidised?
There is nothing embarrassing, the dealerships are ripping mercs owners badly. I never went to them myself and i hope i will not need to do that ever.

 

Thank you. You’re a great help.

 

Maj Dundee I can not get the scanner purchased from this thread to reset the ISM. I am obviously doing something wrong. Can you help. Thank you.

 

Okay forum I need some help. Bought this Autel max Diag Elite MD 802 to help me install the new ISM I bought as discussed on this forum thread. Well it was supposed to be virgin so I guess that is no problem.
However when I hooked this diagnostic tool up to reprogram the servo module I get nothing. Truck is stuck in park in my friends pole barn. I probably am not using it correctly because I have never used one. Was told on this forum it would reprogram the servo module to my truck. Well how do you do that. The scanner says it is not getting information. The scanner does not down load to my computer. What is the deal here Maj Dundee. I bought this on your advise. I admit I've got no clue when it comes to this but i'm frustrated to the max. This shouldn't have been that hard. Can some one who has done this help me out. I can give my phone number to talk personally. Thanks for any help. Spartydano

 

Hi,

when i was pairing my car with the ISM i was using Star Diagnosis system, which is used specifically for Mercedeses only. I had to pair the ISM, then perform learning process. I would think the ISM pairing and learning you can do only with the Star Diagnosis.
When Maj.Dundee was suggesting to get the scanner, he suggested to get a scanner which definitely reads the mercedes system and he meant you have to scan for codes and be sure there are codes to the errors you are trying to fix instead of just replacing the parts.

But replacing this specific part like ISM you will need that mercedes scanner. If you would go and buy a genuine one, even used one, that would be very expensive. There are replicas as well, you can find them in chinese market, these are much cheaper, and they do work. Or you have to find someone or some garage who own one and ask for help.

If you will find someone who has the Star Diagnosis system, but never done adaptation, i can look for the steps needed to go through to make it work. I think i still got it somewhere, i was going through that myself.

 

Spartydano, the scanner came with an instruction manual. Start reading pg. #36 on how to read codes.

Also, you originally never said how you determined the problem was with the ISM.

 

Thank you. I have since found that this code reader I purchased will not pair the ISM. I will probably have to tow the vehicle to MB and have them pair it. Thanks again Spartydano

 

That is true. The scanner did give me codes that I had been aware of. I misunderstood you about this particular scanner being able to pair the new module after replacing it. Sorry about that. Appreciate your response and help. Spartydano.

 

There is another catch with this situation. Here in UK at least. I contacted MB dealership to find out if they would be ok to pair my replacement ISM. I was told clearly, that if the ISM is an issue, they will replace it and perform all pairing learning steps. BUT it will be the ISM from their stock ONLY and it will be a new module, which means - expensive.
They would not want to have anything to do with some module from third party, as they can not give any warranty etc.

 

This does not surprise me in the least. I will find out tomorrow (Monday) from the dealer here. I’m wondering about needing the locksmith license to complete this pairing. Would this device be one that I could use. It states immobilizer.
https://rover.ebay.com/rover/0/0/0?m...2F401968655005
thanks for all your advise

 

It stated the immobilized is one component it can program

 

if i was you i would definitely invest into Star Diagnosis.
The one on your link is the 4th generation one, but it is not enough. You need to have a laptop to which it would be paired to. The laptop has to have specific software installed. If your merc is under 2014 year, you would be enough to get Star Diagnosis C3, the older one, a bit cheaper and it connects to the laptop by wire, i think it is much more reliable.

If you keep searching on ebay or aliexpress, you will find the kit with laptop ready to plug and play, which includes star diagnosis, cables to connect, laptop with the software installed and paired up and so on.

I made a quick search, here are some links of what you need. (If you search further, probably you can find some cheaper listings)

Ideally the link below is exactly what you need:
https://www.ebay.co.uk/itm/New-MB-St....c100005.m1851

If you want to go the cheaper route, you can get C3 generation kit with the HDD only, which includes the pre-installed OS with the software for it to run. So to run this HDD you will have to purchase some old laptop which has got RS232 connection (serial port). Ideally Dell Latitude D630, or Panasonic CF-19 Toughbook. Insert this HDD and run it from that. All would cost a few hundreds less than the first one. I did not search for the laptops, there are loads of them online. Here is the link for the cheaper C3 generation multiplexer:
https://www.ebay.co.uk/itm/MB-Star-C....c100005.m1851

Hope that helps of you decide to go that route.

 

These star diagnosis systems can program/read/clear codes/adaptations and so on on mercs.

 

Yes very helpful. Hopefully can find person to do reprogramming. Will update when I know more. Thanks again.

 

In my area very hard to find service person with diagnostic tools and license to pair ISM with vehicle. Waiting on dealer response. Mine is a new module so hopefully this will help at dealer. I’m hoping it meets dealer OEM requirement as I did not think of that. It is a Siemens 722.9 model so I think that’s good.

The bottom line on this repair is to buy a new module (virgin), have accessibility to the Star Diagnostic data base, VIN numbers, including license to reprogram module. You must have this accessibility. Pair or program module to your vehicle VIN number before installing. This is just more convenient. Then complete the install which is a bit tight. (I had to unbolt drive shaft to get upper heat shield screws and module bolts off). You should be good to go then.

I have read & been told a lot about used modules or refurbished. They may not be able to be reprogrammed even after being virginized. The cost of refurbished and new is minimal so I suggest new.

I am still waiting on finding out about getting my install programmed. This has been a real experience. Hope this aids others having the same issues. Thanks to all who responded and helped. Spartydano

 

Australia S350 2009 W221:
MB dealer new ISM on W221 - $5400 AUD 3-5 weeks
Private Shop but authorised MB repair shop - genuine reconditioned ISM unit - $2800 AUD 1 week