Hello all,
Anyone has experience replacing ism on a 2011 w212 E350? What all has to be removed to get the cramped part out?.
Thank You

 

-1- SHORT BIT:
From what I've seen... you could cut off a Torks bit short to fit between ISM and chassis - That's far better than dropping tranny out....


-2- CHEAT TIP:
You can undo tranny from its mount and torque it sideways to gain extra clearance.

Lets us know what you got... I am in the mood of pulling my ISM out as well to rework the bugs out of it....

 

Thank you for the excellent tips. I will try both this coming weekend and report back. First it was the conductor plate and now I started getting redundancy system activated short to positive code P179A12 , tranny would not shift out of park. 2 days of not touching vehicle and its perfect but I know it's only a matter of time till it happens again so rather dig into ISM.

Thank You

 

I don't have many good words for what this ISM module is up to... It's gonna get you a lot of bang for your bucks!

You are definitely right about dealing with it on your own schedule before it pops a social-finger to get towed. Same reasons for me!

I am planning to open this tin-can to:

1. lubricate dry mechanicals
2. solder the collection of loose pins
3. weatherize the circuit board
4. RTV silicone the leaky connector

This is an essential module acquainted with top VIP's... It has to be in great shape, better than new.

In the mean time it may respond well to "car reboots".
🤞

 

To illustrate @CaliBenzDriver tips, you can also see this video on a S-Class. For illustrations purposes only


or

 

Ok, so the ism can be removed with the right tools and also dropping the transmission bracket. I'm stuck at the part where I'm not sure if the new ism is placed in Neutral or Drive etc during install. 1 video says to place into neutral and another says place into drive before bolting ism in?

 

you need ISM and gearbox to be in a matching gear position.
The video shows how you can shift the gearbox with a pair of pliers, right?

 

Correct but how do I know which position the ism is in? It's motor driven so if I try to crank the ism manually I might damage it? Or maybe I'm over thinking this.

 

the ISM has engravings showing where it is located... (N for new and P for used)
you need to manually dial the tranny to match the ISM position you've just read.

I am curious how did you manage to access the side screws to remove ISM unit from the car? I want to get my ISM out too... how much time to drop it?

++++ Don't try to manually spin the ISM gear output. Dial tranny to match the ISM position.

++++ Spread RTV silicone to provide good weather seal to connector (away from contacts).
✌️

 

Ok, so I'll just move tranny to N and slap it in since ism is brand new unit. I removed it by dropping rear transmission mount which is very easy and then using T30 bit on a slim torx dedicated wrench from Amazon. The ism bolts are super loose and took almost no torque to remove. Once I had the car on ramps it took all of 50min to remove taking my time.

 

Great matching in N !
It's amazing you noticed how bolts are loose on these cars. Some bolts are made of aluminum, "one time use only" at least on timing covers.

Can you link the good AMZ wrench ?

Do you want to spend 100 save 20x ?

 

Thank You for all the help! I used the cheap set just had to extend the handle.

 

thanks that looks good, I think I do have a set like this.

Big saving... if what i was reading is correct (pls correct me) the nice scanner
LAUNCH C-READER ELITE 431 near $100/120 should be able to copy cat old ISM into new one.
Double check that ability to x-code.

I am planning to try and hack the Android on that scanner for fun - My ISM will get boosted not replaced.

 

Hello,
Currently I'm using this 1 worked perfect during conductor plate change.

 

That one is also great for working on the panoramic roof. Either creaking noise, or the motor slipping issue

 

Wow so cute n cheap.
I BOUGHT IT 5 minutes ago.....

 

Replacement complete, only difference was the new unit came set in P position so I did not have to manually move transmission into Neutral. Transport protection and calibration both worked with the scanner I referenced in prior post. See how long this lasts.
Thank you all who posted and helped. Happy Holidays

 

hello, any update on this? I have the same problem… it’s been ongoing for the last 3 months. It’s been such a pain… I have had an independent shop replace the ISM with new and reprogram… same issue after a week. Also replaced steering column shifter. Still same problem. Changed both main and auxiliary batteries. Still the same problem. I need some hope and a miracle…

 

What are the exact symptoms of your issue?

 

Mine has been working fine ever since it was installed. Perhaps you received a faulty unit?

 

New shifter and batteries with little results...

In order to locate the exact miracle you ordered, we need a good chassis scan to help you diagnose this issue!


Your ISM issue is shared by many to various degree without any fault code.

Your ISM acting up pretty much guarantees ECU/TCU are also acting poorly...

You can try whole chassis reboot (CGW/ESP) to see if chassis responds well to that free temporary relief.

Let us know.

 

ISM issues are fairly common in the W212 models, especially as the car gets older. The Intelligent Servo Module controls gear shifting electronically, so when it starts failing, you’ll often notice symptoms like the transmission not engaging, stuck in park, or random warning messages.

Before replacing it outright, it’s worth checking the wiring harness and connector pins for corrosion or loose contact — sometimes a simple cleaning can fix intermittent faults. If replacement becomes necessary, make sure to get the ISM coded properly to your vehicle’s VIN using STAR Diagnostics, otherwise it won’t communicate correctly with the transmission control unit.

Also, avoid buying used ISMs unless you’re sure they’ve been properly reset (“virginized”), because once coded to a car, they usually can’t be reused without specialized tools. A new or remanufactured unit from a reputable supplier is often the safer choice in the long run.