Mercedes ML350 W166 Main & Auxiliary Batteries replacement. Stuck in Park, not shifting. 

Before you removed everything, it looks like there is a small cover that can be removed from the side panel of the trunk area. I suspect that is the access door for the auxiliary battery. Thank you for posting. Knowing the location of the battery and what to look out for helps me out a lot.

Thank you so much for this video, not a lot of ml350 vids out there.

Good video. Did one here at our shop and only need to remove one of the metal anchors (t-40), the two top "T'" hooks (t-30) and the cargo cover cup (t-30). unplugged 12v outlet and pulled the panel out enough to remove the battery. Took about 8 minutes total to remove and install.

Thank you. This video was very helpful! And, yes it saved me a lot of money as well!

auxiliary battery is not the cause of not shifting. even auxiliary battery is not connected, it will still shift. main battery needs to be change when not shifting. also, you didn’t need to do all these to replace it, just take that small cover and use a 10mm to take the bolt out. hope this will help for viewers. nice video though thanks

Really good video, definitely help me save a lot of money on labor cost. 👍👍👍

This is a bloody stupid place to put a battery. Definitely over engineered and as you say - all to get you to visit the dealer. Excellent video

Good video, WELL-DETAILED. Mercedes Benz could have designed it better for easier access

Really appreciate your video. SO helpful. Thanks from New Zealand. 10/10.

Your car wasn't shifting in gear because main battery was already bad and voltage value before starting engine was not high enough for transmission comp to operate so it went to limp mode.

Great video guys, this was very helpful

Thanks for uploading this video, I could change the battery with no problem! Your explanation was very accurate!! Cheers!

Many thanks for the video. Its hard enough to accept that it is so extremely hard to change a battery in this car.

Fantastic video..thank you...all the best

Thanks for the video. I just replaced the main and auxiliary batteries on my 2013 ML350 Bluetec. Just a few suggestions. No need to completely remove the felt liner, just the two retainers on the battery side (you can access the battery no problem), I even left the bottom styrofoam panel in place as well. Also, there's no need to remove any weatherstripping, you can reinstall the side panel using a plastic trim tool and fingers to position the weatherstrip edges back to their correct positions. Saved myself a bunch of money doing this myself.

That auxiliary battery is identical to the type commonly used in burglar alarms. It would, no doubt, be much cheaper from such a supplier. It's just a sealed 12 volt 1.2Ah lead acid battery, after all.

Amazing video! Thank you!

Thank u so much, the same thing has happened to me my car wouldn’t shift at all smh 😢!!! Thanks again

The main function of the Aux Battery is to provide voltage to "stop start" function (support the main battery). In this case if your main battery is dead you have the Aux battery (secondary) to back it up until you can get the main battery charged or replace.

Thank you for this video it helped me

Thanks fo this video. Great info

Thank you 😊 I was wondering what that extra red tipped thing is, thanks for explaining its the vent hose

Nice good to know thank you for making this videos 📹..thank you

Thanks for the share. Nice Job

Grateful video 👍

Great job on vid

Great job 👏 👍 👌 🙌 😀.

Great video thanks

My GL350 has the same exact battery locations, really a pain to access them. I have a totally flat battery due to travel restriction and not able to come back in time. Managed to jump start with a power bank, let it idle charging for an hour then connect a Ctek MXS3.8 charger for 3days totally charged, but am having ALL fault codes poping out on the dashboard, all meters are not functioning, including speedometer, rpm, temp, etc, gear shifter works but not displaying on the dashboard. Same incident happened last year also due to covid, sent to workshop to reset all codes, but now still figuring out how to clear those codes :( great video as not many info on how to get access to the battery, the aux battery is way way too much work.

can you please do a video on how to remove the tail lights from these vehicles. My led turn signal went out and dont know how to remove the tail ight. thanks.

Great video, so what is the price by hour for installation of battery from Mercedes?

Thank you , helpful

Hi, While you give power with the Volvo battery, you did not disconnect the battery from MB while changing with the new one? since I guess you could done this to prevent system failure not recognizing the system if you switch off the power, yes?

did you test old battery before swapping parts? What about the ISM?

Money money all these stupid useless operations to justify price. Keep it simple dear Mercedes. Great video thanks.

Just sold a repair to a 17 gle350, same battery setup, today and watched my technician, last car of the day by the way, sweat trying to do this without cutting the mat. Ultimately he said the cover plate goes over it and he decided to cut it. But boy did my jaw drop when i heard Volvesweden say, the matting had been cut in a previous install. How is Benz going to make a car where you literally have to cut the customer's interior with a knife in order to do a battery install for them?

Nice video. Love this type mercedes.But battery place is not good lmao.

Thank you

The W166 gives a warning message when the auxiliary battery is weak. Then, little by little non-critical features like cruise control will stop working (but distance radar will still work because its critical). I suppose that when you reach the point of not being able to select gears, the battery must have been weak for a while.

hi nice video, do you know size off batterey ? i looking to change on my ml350 2012 , cheers

The Mercedes engineers are not stupid. They did this on purpose.

I have a 2006 won’t drive either way but does show it is changing to drive and reverse but doesn’t move. It has a code for pressure to high and three wheel speed sensors and a can code

I had similar problem, car will act up and can't shift out of drive and can't turn off the car. Find out it was corrosion in the radar sensors, in the back bumper.

Do you need to feed power to the terminals under the hood while changing out the main battery? Is there repercussions if this is not done?

Did you use a battery trickle charger to hit reset the setting when unplugged the battery???

So the panel opening on right rear doesn't reach battery?

Wow that much work just to get to the auxiliary battery 🙈 I got older model 2007 and my auxiliary battery 🔋 is right behind my main battery under the passenger seat. I see on your car here a little entrance panel right above the auxiliary battery 🔋 I’d think that’s the purpose of the entrance for replacing the auxiliary battery.I’d try that first . Before removing all trunk . If not Id just cut around it like you do for the battery under the seat when you first replace the battery it requires to cut the carpet 🤷🏻‍♂️ not sure why you need cut into carpet instead make it already accessible 🤪It would be very expensive to replace the auxiliary battery by the dealership 💀If customers has to go trough that much work as you guys did 🧟‍♂️ good job tho 👌🏼

автору респект!

All this just to drive your car again, nice job mercedes 👏

at 12:01, to feed the power. If you cannot move the passenger seat forward and upward even if the power was fed at positive and negative terminals. Can you still change the main battery? My ML350 has no power now and even with the power feed, the seat cannot be motivated.

And that's why it costs $1000 to change a $12 battery.

That looks like a big rectangular inspection panel or door right above where the battery is. Doesn’t that open up? Sure looks like it does or why would the carpet side panel have that square cut into it. Looks like a little door.

I don't understand why they occupied all the cladding and to get this battery, if there is a specially serving window there that you could reach out, pull out the battery and replace.

Thank you. I 've recently couldn't shift and my key fob was not unlocking the door which I replaced that battery. I had a slow turnover on starting and then it died with dashboard telling me the AUX battery low and do not try to shift. I cut the car off because it would not shift and waited about 5 secs and it started up fine. I have 60% on the under seat AU battery and we didn;t know anything about this one inside the rear trunk wall which from your video appears to be the one that is causing the issues because my Lidgate is damage and will not close properly & I am waiting for my auto repair shop to paint it so we can have it installed. This video is very helpful!. Should I assume the under the seat AUX battery that's 60% is being drained by this 12v one?

Your a LEGEND! Thank you bratko. I had same issue and didn’t believe that simple solution would fix it and thought Mercedes was about to bend me over to repair problem. Turned out my battery was 7 years old and once replaced it all worked perfectly. I owe you bottle of vodka 😀

Mine will shift out of park if I shut off and restart the engine. Does this sound like the aux battery? If so, can I temporarily jump the aux battery from the main battery ?

Hi. Can I contact you directly. I have 2010 ml350. It was stop for 1 year. But when I try to start it the battery was dead. I bring other battery and do contact with it. But the car no crank. Could you please help me what I have to do ?

damn good video, thanks! I will keep my comments about the engineering of that to myself. Other than, WTF!?!

How do you know when your aux is bad? Is 2018 gle 350 the same ?

Agreed, just ridiculous how inaccessible this battery is.

Awesome job bud 👍 but do you know where the fuel pump location? I have the same car !!

Could you not have opened that small door on the carpeted panel?

Why you so worry about embarrassing situation? Video is ok, and thank you. don't worry that much for the people's opinions.

Change my aux battery and the vehicle still stuck in park 2010 gl450 need help

Hi do you know where i can find for the gle

The battery must be registered to the car to tell the computer that is a new one so it will charge it accordingly

The engineer who decided the placement of the aux battery was promoted to VP because the service revenue it generated for the company... Seriously, great video and terrible engineering.

My battery completely dead so I can't move seat up!!!!!! In a bind, have new battery only getting 12.3 on a jump!! Help!! Lol

So it was not shifting but never got an error code about battery malfunction?

Lot of work to change flamming batteries

Mercedes-Benz engineers have not engineered their cars smartly they have engineered them to be the most difficult vehicles to work on everything you try to fix is hard I’ve never seen anything quite like them it must be their way of getting back For us kicking their ass in World War II

Why 2 batteries in the first place ? I'm sure my Volvo XC60 hasn't got 2 batteries like this thank God, what a mess about.

you took way too much apart, the access panel is right there take that out and may need to put a cut in the carpet but it is easier then doing all of that extra work. There is always more then one way.

NEITHER BATTERY IS THE CAUSE OF THE VEHICLE BEING STUCK IN PARK. tHE PROBLEM IS ALMOST CERTAINLY A BAD CLOCK SPRING (MULTI FUNCTION SWITCH IN THE STEERING COLUMN)

Mercedes are so complicated to work one! All access to replace parts are complicated! Just to replace the air filter il takes 3 hours to remove a lot of parts on the engine bay before being able to replace the filter...

What a ridiculous process to replace the aux battery!

That is a burglar alarm or UPS type battery. Not very expensive, horrible thing they have done designing it like that.

Why not just do like this in a simple way for the auxiliary battery replacement? - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ATjTFgx2Yzs.html

Неужели эту мелкую батарейку никак не вынуть через крышку которая над ней? Та через которую лампы менять?

Omg if you just took the left panel out you had access to the battery bud🤯

My battery auxiliary is 3 times more big...

I would buy a American made SUV any day then I would a high dollar so-called great Mercedes-Benz Mercedes-Benz are not made for a poor person although we have to get them when they rich throw them out and then we have to work on them they are very hard to work on

Looks a cheaper car compared to your Volvo, build and design doesn’t look as solid.

Да на хуи , сколько надо чтоб найти эту патарие. Спасибо ребята за хороший обисниние.

German’s cars!

All this work just to remove s battery 😳 hell nah

romana

What a horrible design.. Mercedes need to do better... You are pushing me more to Lexus.... Scotty Kilmer was right! Reve up your engines!!

Stupid Mercedes. I hope Volvo is not like this.

My daughter owns a 450 GL it is the hardest vehicle I have ever worked on in my life Mercedes-Benz sucks their engineers are not very smart it is made for a rich man to spend money at a dealer

There are many cars better than Mercedes and have higher technology and they using just one battery for all operations . Thats why i hate german cars. So complicated. Do i have to take off the whole parts just to replace the battery??? These small details makes Volvo best car in the world.

Какой ужас. Твой английский еще хуже чем твой русский.

Thank you