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Hi everyone I have E350 w212 2012 with blue efficiency technology the eco start/stop feature is not working at all so what are the reasons for this and how do I check the batteries to make sure that they are working probably
The usual reason is that your battery is not up to snuff. Needs to have sufficient voltage and amps. When they get old, they don't provide enough power to keep the start/stop running reliably. ECM keeps enough reserve in the battery for manual starting but not stop start. Happened to me also.
Hi everyone I have E350 w212 2012 with blue efficiency technology the eco start/stop feature is not working at all so what are the reasons for this and how do I check the batteries to make sure that they are working probably
@klaus is right: get your main AGM tested for free at the auto parts store. How old is your battery?
The ECU logic calculates the charge level of the system battery before enabling Engine Cut Off. ECO remains disabled when general conditions are not met (seat belt, temps, driver door,...)
MB has two charging ports (positive/negative) to connect a battery charger without removing any parts. Sometimes good batteries end up discharged by the car for some odd reasons...
Last edited by CaliBenzDriver; 06-22-2022 at 05:08 PM.
There are about 12 possible parameters who can affect ECO, when average car has 8 of them.
You can start dropping parts blindfolded, or you can hook up a scanner and read what is the issue.
I got an error message this morning auxiliary battery malfunction and distrionic plus was inoperative for a while then it was working again do u still thinks that it’s the main battery not the auxiliary battery and one last thing does changes the battery requires system reset or it’s not needed
I got an error message this morning auxiliary battery malfunction and distrionic plus was inoperative for a while then it was working again do u still thinks that it’s the main battery not the auxiliary battery and one last thing does changes the battery requires system reset or it’s not needed
I read it and I know there are conditions that must be meet for it to work I got all the conditions meet but it never works I have also tested my main battery and the test result was like this so this means that I should replace my main battery but I am wonder ing can the main batter cause the error message auxiliary battery malfunction error or I should also replace the auxiliary battery
The test report says "BAD & REPLACE", right? It also specificaly says "FLOODED" which is not what a dry AGM GEL battery is. wrong test setup yields questionable data 😳
A nice IR of 8.17Milli-Ohm was calculated which is fairly low (ie. good in this case).
When your car electronics experience extremely low voltage during cranking time, sensitive modules start disfunctioning... then strange things happen afterwards and people call that grumblings because they don't connect related issues.
There are many good things you could do for this car in that order :
Float charge existing batteries.
Disconnect battery to soft-reset computers.
Monitor live battery charge on IC Display while driving.
Replace badly aged batteries!!
The way both your batteries are acting up at the same time suggest they are not being charged well or discharged while parked or driving.
At the end of the day, another new battery never hurts
Last edited by CaliBenzDriver; 06-23-2022 at 05:24 PM.
I read it and I know there are conditions that must be meet for it to work I got all the conditions meet but it never works I have also tested my main battery and the test result was like this so this means that I should replace my main battery but I am wonder ing can the main batter cause the error message auxiliary battery malfunction error or I should also replace the auxiliary battery
If the main battery is 8 years old, you need a new one, I would replace that one with an AGM battery, then see if the Auxiliary battery light goes away, if not gone in a week or so, replace it as well, I don't believe your car came with a flooded battery, so that must be a replacement or a mistake.
FWIW, my main batt is the original, which puts it at 8 years old, and so far so good. That said, I've had to replace the Aux Batt twice: 1st one under warranty, the 2nd time on my dime. If I were you, replace the Aux first, and get an aftermarket one as it is maybe one third the cost. Notice that dealer replaced my first with an MB unit, and it didn't last long. The cheap one I have in there has already outlasted the dealer-installed batt.
If replacing the Aux batt doesn't cure your issue, then go for a good AGM main batt. Brace yourself for the price on that one...
Consider having someone pull fault codes using Xentry (MB diagnostics) to confirm battery(s) and/or any additional problems may be contributing to malfunction. See attachment for a better understanding of system.
Many thanks to @konigstiger for frequently seeding great information all around.
The above PDF describes the role played by the 12AH AUX battery during ECO cycle.
> Basically both SAM's and ECU work together to switch power sources using 2 power relays. At engine restart, AUX gets connected to supply ALL consumers while MAIN is disconnected to only supply the starter. Then switched back around to normal with ALT supplying all power while driving.
> Voltage YoYo?
The really interesting part on page 3 is about switching OFF the alternator : "If the open circuit voltage (U > 12.5 V) of the additional battery for ECO start/stop function is too low, the alternator's power limit management is deactivated so that the additional battery for ECO start/stop function can be charged"...
"The additional battery for ECO start/stop function is only connected when the alternator's power limit (alternator management) is not active and the on-board electrical system voltage (U > 13 V) is high enough".
The alternator is switched off so the AUX batt does not get hit with a high current jolt of 14.9V when it gets connected for recharge. Once AUX is switched online voltage can get ramped back up. This is the first instance where I see mentioned turning OFF ALT... discharging the main system batt does not exist.
> Rear-SAM takes center stage: "Following on-board electrical system management information is provided by the rear SAM control unit with fuse and relay module (N10/2):
- State of on-board electrical system battery
- State of additional battery for ECO function
- On-board electrical system status
- Requirements for load-intensive consumers ".
The R-SAM is really stepping up to the plate for power Mgt. This ECO feature requires solid collaboration back and forth from a handful of modules built by different vendors. All these design details help us understand how the distributed firmware is driving these modules.
Last edited by CaliBenzDriver; 06-26-2022 at 04:26 PM.
06-22-2022, 10:12 AM
