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I just had to change the battery in my 2013 ML350 4Matic and here is what I learned. These are partial instructions that supplement the instructions in the PDF in the prior post - in other words, the comments below are not all the instructions, you will need to read the PDF also.
IMPORTANT - after you change the battery you will need to reset the ECU as described in Step 8 below or the car will start but you will not be able to switch out of park.
(1) You cannot change the battery unless you have power to the car because you have to move the seat forward and back several times to change the battery. This means you either need a jump, a jump pack, or some battery power left in the battery to supply power to the car while you are doing this change.
(2) You do not need to cut the carpet as described in the instructions. There is enough play in the carpet that you can slide the battery out and the new one in without cutting the flap out in the carpet. It would be easier to cut the carpet to get the battery in and out, but not necessary
(3) Slide the front seat all the way up and back. Pull the carpet under the seat forward and remove a foam block - this will give you access to the positive battery terminal. Loosen the forward positive terminal first, but leave it connected to the positive battery terminal. After you loosen the forward positive battery terminal, slide the seat all the way forward and up.
(4) After you disconnect the rear ground terminal, from the back reach forward under the carpet and pull the positive battery connection up and to the right out of the way.
(5) Tuck the battery vent tube and the negative terminal behind metal flanges in the battery box so they do not get damaged when you slide the old battery out and the new battery in.
(6) You will need a 13mm socket and a long extension to remove the rear battery hold down bracket - this is the only bracket that holds the battery down. When you slide the new battery in and need to reconnect the hold down bracket you will need that 13mm socket, long extension, and shove a piece of paper in the socket to hold the nut in the socket so you can reach the threads in between the battery and back wall of the battery box with the nut in the socket. You cannot reach the threads without using the paper-in-socket-to-hold-the-nut technique.
(7) You will need to re-install the battery box cover. The battery box cover has the rear AC vent attached to it on the top with one plastic push pin. You need to remove the push pin, then remove the vent, then install the cover by itself, then slide in the vent on top the battery box cover and connecting to another vent to the left, then slide the seat all the way back and from the front you need to reach under the seat and carpet and reinstall the push pin from the top. First put the outer pin in the hole, then push the push-pin into the outer pin
(8) 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. I cannot believe that this is not in the owner's manual. Here are the steps to reset the ECU:
- 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
That's it.
The battery you need is model Duralast H8-AG available here priced at $183.99 from Autozone:
This Duralast AGM battery is the identical battery as the Mercedes OEM battery - both batteries come off the same line at a Johnson Controls-owned factory. Two local Mercedes dealers wanted $249.99 for the same battery with Mercedes stickers on it (and both dealers gave me attitude about changing my own battery and told me I could not do it). One Mercedes dealer quoted me $565 to change the battery, battery included - what a deal!
With these supplemented steps it is not rocket science to replace the battery.
Note: I live in warm Florida. My ML350 lives a garage to garage lifestyle. My old original battery went from 100% fine to 100% not working instantly. When I removed the battery it was unusually warm. I think it probably developed an internal short.
Great info..also note we have two batteries...one..the large is an ignition battery..the other auxillary located in the trunk side panel is a controls battery that at least in my ML63 provides power for operation of the gear selection..as said the vehicle will not go into gear if this battery goes dead. It is the size of a motorcycle battery. and stores certain values as well as providing for certain cabin functions..not for the operation of the engine...I don't know exactly it's role but a search will reveal it's complete use
I'll add (in my own experience, exclusively on a '13 ML63), the cap/pin on the rear floor vent/battery cover seems to allow the entire assembly to pivot.
Meaning: if you lift up the tabs towards the rear-seats, and pull straight (towards trunk), it pivots the vent-housing as you pull it out. Re-installation is similar; you line up the end of the vent-housing and push.
I need to disconnect the battery soon-ish again. I'll try to make an attempt (read: remember) to take photos.
I'll add (in my own experience, exclusively on a '13 ML63), the cap/pin on the rear floor vent/battery cover seems to allow the entire assembly to pivot.
Meaning: if you lift up the tabs towards the rear-seats, and pull straight (towards trunk), it pivots the vent-housing as you pull it out. Re-installation is similar; you line up the end of the vent-housing and push.
I need to disconnect the battery soon-ish again. I'll try to make an attempt (read: remember) to take photos.
I tried the pivot-method for the vent but could not get the battery cover to slide on correctly without removing the pin. If you cut the carpet you could probably leave the vent on with the pin, but removing the vent and replacing the pin is very easy.
Great info..also note we have two batteries...one..the large is an ignition battery..the other auxillary located in the trunk side panel is a controls battery that at least in my ML63 provides power for operation of the gear selection..as said the vehicle will not go into gear if this battery goes dead. It is the size of a motorcycle battery. and stores certain values as well as providing for certain cabin functions..not for the operation of the engine...I don't know exactly it's role but a search will reveal it's complete use
Does anyone have the part number and instructions on how to replace the second battery? Since my first battery died I have to assume the second battery cannot be far behind.
Thank you for your help on this. Your instructions made comfortable enough to try.
Originally Posted by 1hdhd
I just had to change the battery in my 2013 ML350 4Matic and here is what I learned. These are partial instructions that supplement the instructions in the PDF in the prior post - in other words, the comments below are not all the instructions, you will need to read the PDF also.
IMPORTANT - after you change the battery you will need to reset the ECU as described in Step 8 below or the car will start but you will not be able to switch out of park.
(1) You cannot change the battery unless you have power to the car because you have to move the seat forward and back several times to change the battery. This means you either need a jump, a jump pack, or some battery power left in the battery to supply power to the car while you are doing this change.
(2) You do not need to cut the carpet as described in the instructions. There is enough play in the carpet that you can slide the battery out and the new one in without cutting the flap out in the carpet. It would be easier to cut the carpet to get the battery in and out, but not necessary
(3) Slide the front seat all the way up and back. Pull the carpet under the seat forward and remove a foam block - this will give you access to the positive battery terminal. Loosen the forward positive terminal first, but leave it connected to the positive battery terminal. After you loosen the forward positive battery terminal, slide the seat all the way forward and up.
(4) After you disconnect the rear ground terminal, from the back reach forward under the carpet and pull the positive battery connection up and to the right out of the way.
(5) Tuck the battery vent tube and the negative terminal behind metal flanges in the battery box so they do not get damaged when you slide the old battery out and the new battery in.
(6) You will need a 13mm socket and a long extension to remove the rear battery hold down bracket - this is the only bracket that holds the battery down. When you slide the new battery in and need to reconnect the hold down bracket you will need that 13mm socket, long extension, and shove a piece of paper in the socket to hold the nut in the socket so you can reach the threads in between the battery and back wall of the battery box with the nut in the socket. You cannot reach the threads without using the paper-in-socket-to-hold-the-nut technique.
(7) You will need to re-install the battery box cover. The battery box cover has the rear AC vent attached to it on the top with one plastic push pin. You need to remove the push pin, then remove the vent, then install the cover by itself, then slide in the vent on top the battery box cover and connecting to another vent to the left, then slide the seat all the way back and from the front you need to reach under the seat and carpet and reinstall the push pin from the top. First put the outer pin in the hole, then push the push-pin into the outer pin
(8) 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. I cannot believe that this is not in the owner's manual. Here are the steps to reset the ECU:
- 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
That's it.
The battery you need is model Duralast H8-AG available here priced at $183.99 from Autozone:
This Duralast AGM battery is the identical battery as the Mercedes OEM battery - both batteries come off the same line at a Johnson Controls-owned factory. Two local Mercedes dealers wanted $249.99 for the same battery with Mercedes stickers on it (and both dealers gave me attitude about changing my own battery and told me I could not do it). One Mercedes dealer quoted me $565 to change the battery, battery included - what a deal!
With these supplemented steps it is not rocket science to replace the battery.
Note: I live in warm Florida. My ML350 lives a garage to garage lifestyle. My old original battery went from 100% fine to 100% not working instantly. When I removed the battery it was unusually warm. I think it probably developed an internal short.
I followed your instructions (somewhat ) and got the job done much easier than expected. Took about 30 minutes. Just one thing. I did not have to reset the ECU to get the car to go into drive. It worked straight away. Here is a link to the video I made.
Thanks for the info. Just changed mine today. Lucky for me my local Sam's club had the battery for $169.67. Went ahead and cut the carpet to make it easier. No need to reset anything except the clock.
Be careful as the metal surrounding the battery is sharp.
We're not so lucky down here with our 2012 X6. Battery is on it's last legs. Priced a brand new one at Autozone @ $160 (supposedly built by the same manufacturer as OEM). Problem is that there's some sort of doohickey on the battery lead that needs to be "coded" to the new battery. $500 job at the dealership.
My thanks as well for the great instructions. Made the job much easier. My only addition is to suggest slipping a large rubber strap wrench under the rear of the battery to help get it up over the rear lip. From then on,, it's just a muscle it out kind of job.
We're not so lucky down here with our 2012 X6. Battery is on it's last legs. Priced a brand new one at Autozone @ $160 (supposedly built by the same manufacturer as OEM). Problem is that there's some sort of doohickey on the battery lead that needs to be "coded" to the new battery. $500 job at the dealership.
That's bogus. Someone is trying to hose you.
Last edited by GregW / Oregon; 08-21-2018 at 03:04 PM.
Thanks to those that contributed to the DIY. Just replaced the battery on my 73-month old 2012 ML350. No problems. I did cut the carpet because it makes things easier and no one will ever see it. Used a long flex grabber pickup tool to install nuts on the holdown clamp which helped. The Duralast H8-AGM was $200 at Autozone.
Cost me about $50 in the end. And there is a way to not have to bring it to the dealer, but I'm on BMW sites and it is true. Unless you're tech-savvy, the dealer has to "code" the new battery. I don't get it but...
Cost me about $50 in the end. And there is a way to not have to bring it to the dealer, but I'm on BMW sites and it is true. Unless you're tech-savvy, the dealer has to "code" the new battery. I don't get it but...
BMWs can be a bit different. I’ve had 3 Ms, and on my 2002 it could take overnight to update the software. Good that manufacturers are moving to over-the-air coding.
BMWs can be a bit different. I’ve had 3 Ms, and on my 2002 it could take overnight to update the software. Good that manufacturers are moving to over-the-air coding.
CORRECTION: $450
And yeah, they can be "different". To be honest, I'm done with German cars after both the X6 and ML. You think you're paying more for reliability, but you aren't.
Next time a Tesla or equivalent, or one of the American Big Three
Our X6 also took a whole day to update, btw.
And yeah, they can be "different". To be honest, I'm done with German cars after both the X6 and ML. You think you're paying more for reliability, but you aren't.
Next time a Tesla or equivalent, or one of the American Big Three
Our X6 also took a whole day to update, btw.
Sorry to hear that. I’m a German car lifer. A few issues but dealer service is light years ahead of Tesla & American makes. Good luck!
Last edited by GregW / Oregon; 08-22-2018 at 10:34 AM.
04-04-2016, 09:54 AM
Thank you for your help on this. Your instructions made comfortable enough to try.
) and got the job done much easier than expected. Took about 30 minutes. Just one thing. I did not have to reset the ECU to get the car to go into drive. It worked straight away. Here is a link to the video I made.
