Auxiliar battery !
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Newbie
Joined: Oct 2024
Posts: 1
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From: Holland
ML 350 BlueTEC 4-matic
Auxiliar battery !
Good morning dear Mercedes fans,
I am the owner of a lovely ML w166 350diesel AdBlue - 2012, 2 years ago ,being the car of my dreams for 10 years now....
I had a problem with the gearbox module (ISM) in December 2024 (while driving for Christmas to my hometown) and was replaced at Mercedes official garage(2 years warranty), then I drove it 4000 km in 2 parts because this is a garage car and I use it for long distances only,
5 days ago I wanted to drive it after 2 weeks of sitting in garage and it was Not possible to place it in D(drive), it was stuck in Parking mode, even though the engine start normal...
I don't have any error message on dashboard.....
I have a question please,
is it possible that the auxiliar batter could create this problem ?
I am thinking also to bring a specialist to the car and maybe he can see the problem with a tester and hopefully have a diagnose...
But till then, did you guys encounter such a thing and what was the solution in your case ?
Thank you and have a great day !
I am the owner of a lovely ML w166 350diesel AdBlue - 2012, 2 years ago ,being the car of my dreams for 10 years now....
I had a problem with the gearbox module (ISM) in December 2024 (while driving for Christmas to my hometown) and was replaced at Mercedes official garage(2 years warranty), then I drove it 4000 km in 2 parts because this is a garage car and I use it for long distances only,
5 days ago I wanted to drive it after 2 weeks of sitting in garage and it was Not possible to place it in D(drive), it was stuck in Parking mode, even though the engine start normal...
I don't have any error message on dashboard.....
I have a question please,
is it possible that the auxiliar batter could create this problem ?
I am thinking also to bring a specialist to the car and maybe he can see the problem with a tester and hopefully have a diagnose...
But till then, did you guys encounter such a thing and what was the solution in your case ?
Thank you and have a great day !
Last edited by George.; Mar 13, 2025 at 05:31 AM.
MBWorld God!
Joined: Dec 2019
Posts: 33,220
Likes: 6,597
Good morning dear Mercedes fans,
I am the owner of a lovely ML w166 350diesel AdBlue - 2012, 2 years ago ,being the car of my dreams for 10 years now....
I had a problem with the gearbox module (ISM) in December 2024 (while driving for Christmas to my hometown) and was replaced at Mercedes official garage(2 years warranty), then I drove it 4000 km in 2 parts because this is a garage car and I use it for long distances only,
5 days ago I wanted to drive it after 2 weeks of sitting in garage and it was Not possible to place it in D(drive), it was stuck in Parking mode, even though the engine start normal...
I don't have any error message on dashboard.....
I have a question please,
is it possible that the auxiliar batter could create this problem ?
I am thinking also to bring a specialist to the car and maybe he can see the problem with a tester and hopefully have a diagnose...
But till then, did you guys encounter such a thing and what was the solution in your case ?
Thank you and have a great day !
I am the owner of a lovely ML w166 350diesel AdBlue - 2012, 2 years ago ,being the car of my dreams for 10 years now....
I had a problem with the gearbox module (ISM) in December 2024 (while driving for Christmas to my hometown) and was replaced at Mercedes official garage(2 years warranty), then I drove it 4000 km in 2 parts because this is a garage car and I use it for long distances only,
5 days ago I wanted to drive it after 2 weeks of sitting in garage and it was Not possible to place it in D(drive), it was stuck in Parking mode, even though the engine start normal...
I don't have any error message on dashboard.....
I have a question please,
is it possible that the auxiliar batter could create this problem ?
I am thinking also to bring a specialist to the car and maybe he can see the problem with a tester and hopefully have a diagnose...
But till then, did you guys encounter such a thing and what was the solution in your case ?
Thank you and have a great day !
Out Of Control!!
Joined: Apr 2019
Posts: 12,191
Likes: 6,889
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Good morning dear Mercedes fans,
I am the owner of a lovely ML w166 350diesel AdBlue - 2012, 2 years ago ,being the car of my dreams for 10 years now....
I had a problem with the gearbox module (ISM) in December 2024 (while driving for Christmas to my hometown) and was replaced at Mercedes official garage(2 years warranty), then I drove it 4000 km in 2 parts because this is a garage car and I use it for long distances only,
5 days ago I wanted to drive it after 2 weeks of sitting in garage and it was Not possible to place it in D(drive), it was stuck in Parking mode, even though the engine start normal...
I don't have any error message on dashboard.....
I have a question please,
is it possible that the auxiliar batter could create this problem ?
I am thinking also to bring a specialist to the car and maybe he can see the problem with a tester and hopefully have a diagnose...
But till then, did you guys encounter such a thing and what was the solution in your case ?
Thank you and have a great day !
I am the owner of a lovely ML w166 350diesel AdBlue - 2012, 2 years ago ,being the car of my dreams for 10 years now....
I had a problem with the gearbox module (ISM) in December 2024 (while driving for Christmas to my hometown) and was replaced at Mercedes official garage(2 years warranty), then I drove it 4000 km in 2 parts because this is a garage car and I use it for long distances only,
5 days ago I wanted to drive it after 2 weeks of sitting in garage and it was Not possible to place it in D(drive), it was stuck in Parking mode, even though the engine start normal...
I don't have any error message on dashboard.....
I have a question please,
is it possible that the auxiliar batter could create this problem ?
I am thinking also to bring a specialist to the car and maybe he can see the problem with a tester and hopefully have a diagnose...
But till then, did you guys encounter such a thing and what was the solution in your case ?
Thank you and have a great day !
Realize that replacing the costly ISM did NOT really fix your issue.
At this time it's a really good guess to suspect the AUX Batt circuit (Batt + fuse).
Use any cheap voltmeter to measure your AUX voltage near 12.5Volts
Then use a CTEK or equivalent float charger to top off both batteries. (Alternator IS NOT a good battery charger).
Do purchase on (Internet: Amazon) a $150 Launch cReader MB Elite scanner to diagnose your chassis - It'll pay for itself the first time you use it (Skip the toy Bluetooth gizmos testers). Specifically buy a "Launch" everyone around here likes to use.
The bottom line here is you have a voltage disruption preventing normal CAN Bus functions.
Fix may be as simple as...:
- Battery charge
- Reboot chassis
- Scan
- Clear faults
Cost: 0.
Never let your MERCEDES DRAIN YOUR BATTERIES flat without a "float charger".
Last edited by CaliBenzDriver; Mar 15, 2025 at 05:27 PM.
MBWorld God!
Joined: Dec 2019
Posts: 33,220
Likes: 6,597
Mr. G.:
Realize that replacing the costly ISM did NOT really fix your issue.
At this time it's a really good guess to suspect the AUX Batt circuit (Batt + fuse).
Use any cheap voltmeter to measure your AUX voltage near 12.5Volts
Then use a CTEK or equivalent float charger to top off both batteries. (Alternator IS NOT a good battery charger).
Do purchase on (Internet: Amazon) a $150 Launch cReader MB Elite scanner to diagnose your chassis - It'll pay for itself the first time you use it (Skip the toy Bluetooth gizmos testers). Specifically buy a "Launch" everyone around here likes to use.
The bottom line here is you have a voltage disruption preventing normal CAN Bus functions.
Fix may be as simple as...:
Cost: 0.
Never let your MERCEDES DRAIN YOUR BATTERIES flat without a "float charger".
Realize that replacing the costly ISM did NOT really fix your issue.
At this time it's a really good guess to suspect the AUX Batt circuit (Batt + fuse).
Use any cheap voltmeter to measure your AUX voltage near 12.5Volts
Then use a CTEK or equivalent float charger to top off both batteries. (Alternator IS NOT a good battery charger).
Do purchase on (Internet: Amazon) a $150 Launch cReader MB Elite scanner to diagnose your chassis - It'll pay for itself the first time you use it (Skip the toy Bluetooth gizmos testers). Specifically buy a "Launch" everyone around here likes to use.
The bottom line here is you have a voltage disruption preventing normal CAN Bus functions.
Fix may be as simple as...:
- Battery charge
- Reboot chassis
- Scan
- Clear faults
Cost: 0.
Never let your MERCEDES DRAIN YOUR BATTERIES flat without a "float charger".
Out Of Control!!
Joined: Apr 2019
Posts: 12,191
Likes: 6,889
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
SETUP FOR FUNKY THRESHOLDS
Don't forget to link your reboot thread so it is extra clear : ) https://mbworld.org/forums/e-class-w...eboot-how.html
Later today I will write a quick explanation about...
how low/variable/unstable voltages are used to disrupts CAN modules (active vs. sleep)
and why chassis Reboot
Last edited by CaliBenzDriver; Mar 15, 2025 at 06:29 PM.
MBWorld God!
Joined: Dec 2019
Posts: 33,220
Likes: 6,597
Trending Topics
Out Of Control!!
Joined: Apr 2019
Posts: 12,191
Likes: 6,889
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
voltage sensitive princess
I did write how low voltage may occasionally rope in customers with unsettled ownership experience. 
> Translation:
-- We can realize that Mercedes designed awesome chassis that run right when daily driven and become service oriented when driven seldom.
-- The simple shortcut is to maintain battery voltage with an automated charger - Who needs endless aggravations ???
> Translation:
-- We can realize that Mercedes designed awesome chassis that run right when daily driven and become service oriented when driven seldom.
-- The simple shortcut is to maintain battery voltage with an automated charger - Who needs endless aggravations ???
Last edited by CaliBenzDriver; Mar 16, 2025 at 01:34 AM.
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MBWorld God!
Joined: Dec 2019
Posts: 33,220
Likes: 6,597
I did write how low voltage may occasionally rope in customers with unsettled ownership experience.
> Translation:
-- We can realize that Mercedes designed awesome chassis that run right when daily driven and become service oriented when driven seldom.
-- The simple shortcut is to maintain battery voltage with an automated charger - Who needs endless aggravations ???
> Translation:
-- We can realize that Mercedes designed awesome chassis that run right when daily driven and become service oriented when driven seldom.
-- The simple shortcut is to maintain battery voltage with an automated charger - Who needs endless aggravations ???
