Hello,
My E-class has no communication with the battery sensor and the Start-Stop function doesn't work at all.
I have also checked a voltage on the cable comming to the battery sensor, It sends 9,7V, and as far I know (i have checked cable voltage at the car of my neghbour) and there should be 2,7V.

I have also checked that this cable from Battery Sensor goes directly to SAM module, so I guess that SAM module generates wrong Voltage for Battery Sensor.

I would like to also point out, that after starting an engine there is no current in all cigarette lighters (after around 20 seconds the car turns all cigarette lighters off)

Any ideas what can cause these problems?

 

Wondering what was the resolution? Did you have to change the battery negative cable which has the sensor on it? I have these codes but my car won't restart after an ECO stop. The start-stop signal button is green. Have to put car into N or P and it will restart.

 

I have just messed up with the cables on BMS (plus Pole), one of them is also connected to the Battery Sensor. I compared it with another Car and connected them correctly - this was the solution. I would replace a battery Sensor in your situation, and check what is happening.

 

Is it possible to mix up wires going to battery sensor? The clip seemed to go in only one way.

 

VENT hose !

The battery vent pipe in this picture was unplugged... perhaps the vent location on this aftermarket AGM is not compatible.

The (rear) SAM doesn't really feed any "voltage" to the digital LIN battery sensor. It's a serial data line used to collect Voltage, Current plus Temperature through the (-)Neg. battery post.

The Sensor power supply comes from a short wire run to Batt(+) side.

I almost fell of my chair when I saw my Benz is built with a Hyundai sensor, the original Bosch must be too expensive...

 

The vent hose was only disconnected temporarily while checking the entire negative terminal cable which sorta wraps around it.
The aftermarket AGM has a vent connection at the same location as the original OEM battery so that shouldn't persuade you against an aftermarket battery. These AGMs batteries are at spec or higher than the original Mercedes batteries as long as you go with a good brand / top of line.

I don't think the U113E87 code appears in xentry and often only appears in generic / enhanced OBD scanners so it may not be important.

Hyundai might have a patent on it or something making it the preferred supplier in the past.

 

Are you sure this is the correct sensor for the car. It was made in 2014!!!

 

Yes it is for a 2015 vehicle and came with vehicle. Plants likely source parts a few months or a year before manufacturing.

 

I have the exact same sensor and no similar "stored faults" in SAM on W212-'14. I do see wild charging issues that may be attributed to flaky COMS with batt sensor ie. the same thing reported by your Front-SAM.

When you power cycle your car from a failed ECO Cycle restart, it's like rebooting it fresh with a cleared state.
​​​​​
Front-SAM faults...:
W212 schematic shows the front MAIN AGM Batt. sensor is connected to the REAR-SAM, not to the closer Front-SAM.

In other words FrontSam reads sensor through an indirect network connection over the CGW Gateway. FrontSam is complaining about not reading LIN bus sensor from RearSam on a separate network!

- It'd be easy to assume the Hyundai sensor is disfunctioning when COMS are randomly being impacted by other offenders.

DTC's look straight forward but it's not unless you have tested actual fix.


MY'14W212 - LIN bus Battery Sensor ....$150


Front Batt Sensor connects to... REAR-SAM 😭

 

Hello, i have the exact same issue on my car, did you manage to fix this ?

 

This blue/white wire going to the rear SAM, what is the fuse / relay for this ?

 

Did you fix your issue by changing your battery sensor on the negative pole ? or was something else?

 

My 2010 W212 E220 diesel has suffered with battery sensor comms issues for several years.
Main symptom was radio and rear 12V power sockets would go off 14 seconds after start.
Occasionally coming back on after several minutes.
Also 'Pre safe inoperative message' in warm weather.

Battery charging continually at 14.93 Volts (too high even for an AGM battery)

[Technical detail: A meter (or scope) on battery sensor blue white wire shows a serial data packet every 14 seconds from the sensor, this included voltage & current levels, possibly more. Transmission is over LIN bus back to the rear SAM. With meter, a working sensor shows a volt or two momentarily every 14 seconds.]

The symptoms show that the interpretation of the signal from the battery sensor is falsely indicating as low-battery status and is hence increasing output command to the alternator to change at maximum rate.

Work around was to disconnect 2 pole battery sensor connector at the battery sensor and leave it disconnected forever.

Battery continues to charge, but at 14.4v as set by the alternator as a default in absence of charging voltage being determined from the battery sensor readings.
Downside is that some systems don’t work, eg hill hold braking system.

Changed sensor a while back. Some apparent improvement for a few months, but then problems returned.

Battery was eventually getting a bit weak in very, very cold weather.
New battery made no difference to Battery sensor comms problems.

[Technical Note: It may be important to ensure the battery sensor 2 pole connector is disconnected before removing battery negative terminal and re-connected after re-connecting battery negative terminal. When removing/ replacing battery and other times when it is necessary to disconnect the battery.]

Had another go at fixing today, and at first glance seemed to have fixed problems.

Steps:

1) Disconnected battery sensor 2 pole connector

2) Removed battery negative terminal so as to disconnect battery

3) Gained access to rear SAM. In boot right hand side.

4) Removed rear SAM sufficient to get to connections behind. 3 off 10mm nuts.

5) Identified smaller blue multiway connector on rear or SAM. Removed and replaced a couple of times having observed all terminals looked clean and dry. This was to re-established any high resistance connections that may have developed in the 13 years since the car was new.

The connection of real interest is the blue and white wire that comes from the battery sensor.

6) Then took the opportunity to remove/ replace most of the other connecters on the rear SAM.

7) Re fixed SAM into position.

8)Trace Blue and White wire back from the SAM to a little white 8 way connector sitting atop a blue connector on the rear right wing. Removed and replaced this connector a few times in case of poor connection. <<edit 02 August 2023 connector colour corrected

9) Put covers back on.

10) Reconnected battery negative terminal so as to re-connect battery

11) Re connected battery sensor 2 pole connector.

Limited success <<edit 02 August 2023 from this point to end.
At first all appeared fixed.
The car was started and ran normally without radio shutdown and other previously mentioned faults.

Battery was charging at 14.2 volts. Indicating that battery charging system was correctly working normally again.
All 12 V power socket working. Hill hold braking system working.

Unfortunately the next day previous problems recurred.
Reverted to the work-around of disconnecting the batter sensor at the senor again.
The only obvious downside of this is the lack of the hill-hold brake system.

Next step would have been to open up the rear SAM, but really did not want to dig that deep into complex systems.

end

 

Resolved the u113e87 error on my 2015 W205 C250 BlueTec which constantly showed as Stored (not Active), clearing the code, and it would come back within a minute.

Years ago, Mercedes replaced the battery sensor, and replaced it with A0009056507 which has SW 17.11.

This kept generating U113e87 errors "Communication with the battery sensor has a malfunction. The message is missing." in the Front SAM.

My Front SAM was part A2059006818 with SW A2229027310 version 14/26.

I updated the Front SAM with Software Update A2229021112 version 15/29 using an OTOFIX EvoScan, and the errors in the Front SAM have gone.

The Stop/Start hasn't come back on as yet, as i'm guessing the car was never charging the battery properly due to the missing message, probably caused by the mismatch of versions between the Front SAM and the Battery Sensor.

Btw, I had already bought a new battery, battery sensor, replaced connector, and none of that made any difference to the u113e87 code.

I did get some weird issues after doing the update, the front SAM got very confused and enabled the AP26 (Backup Battery), I had to disable that in the PNM SSN (or something similar) within the SAM. Also the Windscreen wipers stopped working, but restoring a backup of the coding of the SAM from before the software update fixed that.

I have noticed that the BN value in the hidden service menu is currently switching from 0 to 82 to 0 to 82 to 0, etc... I have no idea if this is normal or if I need to re-enable the AP26, as i've noticed the blower seems restricted, so the 82/0 is probably the remaining issue.

Also the Front Radar sensor had a fit and stopped Collision Assist Plus from working and throwing an ESP error on the dash, updating the software, restoring the coding and running the post programming fixed that.

In the Live Data section for the ECO Stop/Start, the "Engine stop inhibit : Battery" is now showing "Not Active", whereas before it always showed "Active".

 

This is excellent work and great news !

Thank you for figuring out what MB could not.

 

Still struggling with this. The error codes have not come back, but it seems then when I successfully Programmed A2229021112 (ver 15/29) to the front SAM, the subsequent coding is failing, and the AP26 re-enabled on the car, which I don't have. The AP26 is the backup battery, whereas the W205 has the capacitor instead.

Anyway, the battery will charge, but then gives BN: 82/10, and it's the 10 which is confusing, as this code is not listed anywhere. I'm assuming it's some sort of error code.

The Battery Inhibit is NOT ENABLED, which is progress.

i'm waiting on Autel for an answer as to why the coding is failing, and what it's failing on.

Reverting the programming to A2229027310 (ver 14/26), and reverting the coding causes the u113e87 errors to return, but a full charge from a NOCO Genius Pro 25 will allow the ECO Stop/Start to work, but once the battery depletes, the car doesn't like charging the battery to full, which means back to square one.

 

This is not simple... if i understand you correctly you can't upgrade firmware because it calls for an AUX Batt and your car has a big Farad-Caps module, right? So that is not a compatible software upgrade path.

And when you back track to essentially true original stock (??) the battery doesn't charge so well and ECO has issues, correct?


-- Can we try a different route using just the stock firmware base?

My chassis came from factory with a jacked up voltage control that was causing deep battery drain while driving.

If you can summarize things up to now, I may be able to help you out of this chaos.

What's going on with battery sensor module? Does it report volt, amps and temp??
.

 

Ok, a breakthrough of sorts.

First of all, I only have the U113E87 errors and no battery drain issues, other than if I leave the car for 10 days or so. Also, the Battery Sensor appears to be working, and reports values.

In short, updating the FRONT SAM has fixed the U113E87 error and DOES resolve the ECO STOP/START working, as my W205 is now properly charging the battery, seems it was charging the battery at a much slower rate when the U113E87 error was appearing. Which also explains why I was getting low battery messages to my phone after a week.

Now this is where it gets interesting, but in short, when Autel applies the coding attached to the old software (A2229027310 ver 14/26) to the new software (A2229021112 ver 15/29), it can't write some of the settings as the different versions must have different settings within the coding, and generates a coding error, this was also causing BN xx/10, the 10 being some sort of error status preventing the ECO Stop/Start from working. With Autel, it will offer you other coding files, which I assume are from other vehicles. I applied another coding file, which applied correctly without errors, and that successfully resolved the ECO Stop/Start and showed a BN 76/100, the 100 being the important status code to enable the ECO Stop/Start. I also noticed the battery charge level increases much more quickly.

But..... as the Front SAM controls lots of stuff, the Automatic High Beam LED headlight function stopped working, due to me applying a different coding directly from Autel, which most likely was from a car that didn't have the LED automatic high beam headlights. I then re-applied the old coding file from my car (A2229027310 ver 14/26), which again errored whilst being applied, but this time everything appears to work.

I have a ticket logged with Autel for them to explain why my original coding for (A2229027310 ver 14/26) will not apply to (A2229021112 ver 15/29).

The upshot is, the remaining issue is with coding, and not an incompatibility with the new software. So for anyone programming directly with Xentry/DTS Monaco, they may not even get the subsequent problems I had, as it might be linked to Autel only.

The big test will be when the car isn't driven for a few days to see if the ECO Stop/Start fails again.

 

Autel is junk for mercedes when it comes to coding and updating, same as all aftermarket

now if you want to spend your money on junk, never know when it's going to ruin your car, get autel


No issues with the real tools

BenzNinja members don't worry, ever

you have the dealer at home


good luck with the ticket, response will be the same as always aver years: "sorry..... we are working on it"

 

All fixed, U113E87 gone and eco stop/start fixed.

 

Great
This is really going to help many.

 

Were you able to resolve the dtc faulty communication with battery sensor.? I have the same trouble codes and have gotten nowhere as to resolution? Please advise. Thank you.

 

which codes do you have exactly?

if it’s U113E87, this is because the
firmware installed on the battery and Front SAM are not compatible. You probably need to update the firmware on both. You will need a diagnostic tool to Programme and then possibly Code both. I used an Otofix Evoscan Ultra to do it.

 

Hi and many thanks responding.
I have a 2016AMG GTS.
I have U113E00 “communication with battery sensor has malfunction “
code U100800 LIN bus1 has malfunction
code B1FC287 “starter battery has malfunction, message is missing”
These codes are all active and stored and appear under SAMR, rear SAM signal acquisition control unit.

I also have 3 SAMF codes stored as opposed to active :
B215F71 relay circuit 15R has malfunction, actuator blocked
B172B15 right parking light fault
B181E2A hood sensor malfunction

Car operates fine, just the eco start stop is not working which caused me to check codes in the first instance.

Spent ton of time researching this but to no avail. Trying to avoid trip to dealership and getting turned upside down and shook.

Any insight will be greatly appreciated.

 

you have a completely different car and issue, this thread isn’t for you. even so, the error code is explicit, the battery sensor is either unplugged, not working or the wiring harness is damaged, or in your case the Rear SAM is damaged, as your car implies it’s connected to the rear SAM. Are you sure no one has unplugged the battery sensor to disable the stop start?

Your car likely has 2 batteries, have you checked them both? Check on PartSouq and check the breakdown of the car.