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.
Junior, you saved me a lot of time and expense! Thank you!!!
I have a 2013 GLK350 which started to not want to go into gear several months ago. The transmission fluid needed to be refreshed so I did that along with a transmission filter. Of course the problem persisted. I started researching and replaced the main and alternate batteries. And the problem persisted. I then pulled the P172A00 code with a Carly scan tool and purchased a new steering column switch assembly. As you said, that replacement was very easy and the problem appears to be resolved. Thank you again for this post, you really helped me! Dave
Great news! Mine gets worse when it gets cold… still throwing no codes but I’m willing to try the shifter. Where did you get yours? I couldn’t find last I searched.
Joe
This happened to me. Car is randomly stuck in park. Turning engine off, open/close the door and trying it again usually fixes it. One day, I got the red dashboard battery light warning. Tested the battery which was fine. Alternator was not charging. After replacing the alternator, the stuck in park issue never came back.
Juan, the ISM (servo module) does need to be configured to the car. The SCM does not. The SCM is the shifter module and is about $600. The servo module is about $2000. Have you pulled the codes? As I always replace the most inexpensive parts first, I replaced the auxiliary battery first and then the primary battery and along the way, I refreshed the transmission fluid and filter.
Thanks for the reply, Dave. In my case I get the codes: U1420 - CAN communication with the control module 'N80 (SCM/MRM)' is faulty and P172A00 - The Direct Select lever is faulty. I already changed all the batteries and no other codes were present or stored. I used an AUTEL MaxiPRO MP808TS scanner. I already bought the module at Mercedes-Benz Parts Store online for $367.00 only. After researching on the web various online OEM parts stores I can teel that they have the lowest prices. Thanks for the info again and I hope that this information can help others with the same problem. As soon as I change the part, I will let to know the results for the benefit of others.
Thanks for the reply, Dave. In my case I get the codes: U1420 - CAN communication with the control module 'N80 (SCM/MRM)' is faulty and P172A00 - The Direct Select lever is faulty. I already changed all the batteries and no other codes were present or stored. I used an AUTEL MaxiPRO MP808TS scanner. I already bought the module at Mercedes-Benz Parts Store online for $367.00 only. After researching on the web various online OEM parts stores I can teel that they have the lowest prices. Thanks for the info again and I hope that this information can help others with the same problem. As soon as I change the part, I will let to know the results for the benefit of others.
Hello, i hope everyone is having a good day. My name is Gio and I'm a new member of the mbworld forum. I purchased a decent Ml 350 2013 (80k miles) over a month ago and everything was going buttery smooth and i completely fell in love with the vehicle. However last week while reversing out of my driveway my car lit up all the yellow lights on the dash (traction control - esp - tire pressure control etc.) i switched to P and the engine was idling rough with the rpm gauge wobbling between 500 and 1000. Switched off the car and back on everything was back to normal only with the check engine still on. Drove for around 3 mins and the check engine light went off on its own. On my maxiscan reader i only got the following code stored. P061A Internal control module torque performance.About a week later i first ran into the the selector problem i reached home and wanted to switch from D to R the selector was stuck in D and only allowed me to switch from D to P, and once the car was in P position i couldn't switch to any other gear (D N or R)After switching the car off and then on everything went back to normal instantly and the selector was working fine, but this selector problem reoccurred a couple of times this past week. And similar to what the other members mentioned i also got the 2 codes P172A00 - The Direct Select Lever is Faulty.And U1420 - CAN communication with thecontrol module "N80 (SCM/MRM)'
Can anyone please guide me with how i should go about troubleshooting this issue and if any could the two incidents i mentioned (P061A and the selector issue) be related in any way or form? (Aux battery maybe?)
Hi there I was hoping if you had a moment you can could give me an honest opinion of what kind of scanner I can get away with using. I'm on a budget at the moment so really the cheapest option that will still get the job done. Thanks in advance for your time.
Bryan
Originally Posted by JurniorH
Having finally received the Steering Column Module and chasing down all other issues I have finally fixed the problem.
I will however state that my case was a bit different as I had multiple codes that required replacing various things. For example: Normally this problem occurs when your auxiliary battery or primary battery are going bad. In my case neither battery was retaining voltage so obviously that's where I started. The voltage from the alternator was within specs however the batteries were faulty. New batteries were installed. That resolved the first round of issues.
The next issue was the ISM Module as I was also receiving faulty codes. This is not an easy fix to do yourself unless you have the proper equipment as this module requires coding the vehicle VIN. Nevertheless I did replace it and code it which took care of the ISM Fault code.
Last but not least (and was the reason I posted in this thread) BIG thank you to Chasis for confirming my belief as well as pointing me in the right direction to find the part - the SCM/MRM fault code.
Once the part arrived and I replaced it the remaining codes were cleared and the vehicle has been running like new.
Like I said, you really need to pay attention to the trouble codes and a simple scanner will not help. I own various high end scanners including a Zeus with updated firmware and software. I hope this post and thread will help anyone with this issue.
Last but not least having done the work myself I saved thousands. BUT this is not for your average "I change my own oi & spark plugs" type person for the ISM module I mean. Everything else is a walk in the park.
Well done! Thanks for posting the results for the benefit of others.
Originally Posted by Gio Sayah
Hello, i hope everyone is having a good day. My name is Gio and I'm a new member of the mbworld forum. I purchased a decent Ml 350 2013 (80k miles) over a month ago and everything was going buttery smooth and i completely fell in love with the vehicle. However last week while reversing out of my driveway my car lit up all the yellow lights on the dash (traction control - esp - tire pressure control etc.) i switched to P and the engine was idling rough with the rpm gauge wobbling between 500 and 1000. Switched off the car and back on everything was back to normal only with the check engine still on. Drove for around 3 mins and the check engine light went off on its own. On my maxiscan reader i only got the following code stored. P061A Internal control module torque performance.About a week later i first ran into the the selector problem i reached home and wanted to switch from D to R the selector was stuck in D and only allowed me to switch from D to P, and once the car was in P position i couldn't switch to any other gear (D N or R)After switching the car off and then on everything went back to normal instantly and the selector was working fine, but this selector problem reoccurred a couple of times this past week. And similar to what the other members mentioned i also got the 2 codes P172A00 - The Direct Select Lever is Faulty.And U1420 - CAN communication with thecontrol module "N80 (SCM/MRM)'
Can anyone please guide me with how i should go about troubleshooting this issue and if any could the two incidents i mentioned (P061A and the selector issue) be related in any way or form? (Aux battery maybe?)
Thank you so much in advance.
Chassis, any thoughts man? Today i tested both my main and aux battery with a voltmeter they both read out 12.5 V with the car off and 14.5 V with car on.
I really want to get to the bottom of this and go back to enjoying my "new" ML. 🥲
Chassis, any thoughts man? Today i tested both my main and aux battery with a voltmeter they both read out 12.5 V with the car off and 14.5 V with car on.
I really want to get to the bottom of this and go back to enjoying my "new" ML. 🥲
Hey lads, regarding the car stuck in P or not switching gear issue, Since some of you have already experienced this issue is it normal to have these 2 codes "P172A00 - The Direct Select Lever is Faulty." And "U1420 - CAN communication with thecontrol module "N80 (SCM/MRM)'" thrown in the scanner if the issue is due to a dying aux battery?I tested my aux battery today it read 12.5 v with the car off and 14.5 v with it on. However my main battery shows 12.5 v while off and drops to 10v while crancking and goes back up to 14.5 with the car on.. Please any help is much appreciated.
i have finally fixed the issue ( 2 months problem free so far) posting a detailed troubleshooting process soon..
My sincerest apologies for the late reply i gad a lot going on for the past couple of months. Okay guys so back when this issue happened with me i tried literally everything that's been written on the forums : main battery replaced, aux battery replaced, key fob batteries.. None of this helped i ended up dismantling the SCM and turns out the outlet where the shifting stick gets pluged into is tin soldered on the SCM board and the solder with chipped and had broken off. (Shown in red in the attached photo) so all I did was re-weld the part that had been broken and disconnected. And i have been driving my beautiful suv problems free. I am willing to help anyone who's having this problem in depth through whatsapp if any of my explanations wasn't clear enough : here's my number +9613426693. I know it can be a hassle 😂 I've been there.
Gio, it is very generous of you to offer help! I had the same SCM issue on my 2013 GLK350. I replaced the main and auxiliary batteries and then scanned the car with the Carly scanner which pointed me to the SCM. I replaced the SCM and that resolved my issue. Good for you to tear apart the SCM!
I was following this thread since I have similar issue with occasional stuck in N or D.
My resolution was the following:
1. replace AUX battery
2. replace main battery
3. reset ECU
After you are finished reinstalling the new battery you now need to reset the ECU or your ML350 will not switch gears out of park.
- If you have Keyless Go, pop off the Keyless Go button - Insert the key - Turn the key to "ON" - not start - and leave it "ON" for more than 2 minutes - Turn the key to "OFF", but leave the key "IN" for at least 10 seconds - After at least 10 seconds, turn the key to "ON", push and hold the brake, turn the key to "START" and the car should start. Verify that you can switch gears. - If you have Keyless Go replace the Keyless Go button
Dvakata, I am not starting an argument. This is a serious question: If the car throws a code indicating a bad SCM, wouldn’t you agree that resetting the ECU will not resolve the problem?
Dvakata, I am not starting an argument. This is a serious question: If the car throws a code indicating a bad SCM, wouldn’t you agree that resetting the ECU will not resolve the problem?
This was happening to me intermittently, and as time went on more frequently for about a year and a half. I never was stranded though some days it took several turnoffs and back on to get it to shift.
However, on vacation two weeks ago it finally stopped. Went in to CVS for cash and came back out and not a light, a sound, etc. It was completely and totally dead. My husband and his dad and brother took the battery out after jumping enough to move up passenger seat to access the battery without having to remove the seat back. We installed a new battery and it started right up. (Also was the OEM battery that was 11 years old- WOW)
Ever since the new battery has been installed it has not done the weird no shifting thing. Wanted to share as I had been here looking for a fix multiple times. Crazy that I got almost 2 more years out of that battery but again in the 2 weeks since we installed new battery it has not happened when by that point it was happening about every 2nd or 3rd start!
Just wanted to share in case it helps someone else.
Thanks for sharing.
And since I'm here want to give a quick update on my batteries replacement half a year ago you see in this thread.
Few weeks ago I had the same issue starting slowly and progressing to full stuck in D. A quick disconnect of AUX battery (I have a cut out in the carpet) resets shifter, no issues since
Here's an update 2 years later since I replaced both batteries. Shifter has started to act again, this time it went completely numb and I spend on Costco parking 10 min restarting everything. So I gave up and ordered SCM from scrap. Replacement took me 30 min - so far so good.
Attaching photo of original module - seems like serial problem with factory soldering.
I have read most of the posts, when multiple modules or communication issues pop up almost simultaneously, I suspect a bad ground connection or power connection first. Chase down the transmission ground, the engine bay grounds and chassis grounds and make sure there are no poor connections. (Measuring more than 0.2 volts from ground connections to battery ground.). Use a long jumper and check the grounds. They may be loose, corroded, or the wire broken or corroded. Or the connection itself may be poor. If not that, check power sources to modules. First at fuse box, then at module. Voltage variances indicate poor connections or wiring. Don’t fire the parts cannon until you have checked out the circuits.
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.
