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Battery Monitor Unit - J367 Adaptation
Posted: Mon Jan 26, 2026 1:25 am
by JiSingh1
Hi all,
1.0TSI Polo 6C.
Essentially I have the following fault code in the system at times, and I feel like my steering has gone heavier to an extent compared to how it used to be :
U141100: Battery Terminal Recognition - Open Circuit (Intermittent/Stored).
My Research & findings so far suggest the Heavy Steering is a result of "Load Shedding" triggered by the U141100 code, but various fixes or possible causes.
I was looking into replacing the battery monitoring system on the negative ( 6C0 915 181 A ) and therefore i have a question regarding the battery monitoring system (J367) Adaptation.
I noted in the VW workshop manuals/wiring diagrams that it states: "After the installation of a new battery or a new battery monitor control unit, the battery monitor control unit must be adapted via the vehicle diagnostic tester".
Unfortunately that's all it says, and doesn't explain how or what I need to do, and the module is a slave of the gateway so doesn't have its own long coding or anything I believe.
Does anyone have an idea?
Thank you
Re: Battery Monitor Unit - J367 Adaptation
Posted: Mon Jan 26, 2026 10:34 pm
by RUM4MO
I asked this question on a VW forum, and its owner/moderator who is a partner in an Independent VAG repair workshop, and also a proper tech, assured me that when you replace the "lump" on the earth terminal it is "plug and play".
He has found that in some cases where the battery fails, it can be due to a failed/faulty BMU, so typically he will also replace that "lump" when replacing a failed battery, it seems that some VW Group models were worse than others in this respect, and Polo and its "cousins" are not one of them - I only found that out AFTER buying a new BMU which cost "quite a bit"!
I was only trying to improve the car's ability to keep the battery in "good condition" as I suspected that it was getting over charged - but that EFB battery lasted over 10 years 54,000miles, and I only replaced it with the next size up AGM battery because the car was now over 10 years old AND this AGM battery has been waiting to get fitted into my wife's car for too many years!! I still have not replaced the BMU but after having this bigger AGM battery (coded to the car correctly), fitted for a month or so and having witnessed the charging "characteristics" via a plug in DVM in the power socket, I really should get the new BMU fitted and see if anything changes in respect of the charging "characteristics" .
Re: Battery Monitor Unit - J367 Adaptation
Posted: Tue Jan 27, 2026 12:54 am
by JiSingh1
RUM4MO wrote: Mon Jan 26, 2026 10:34 pm
I asked this question on a VW forum, and its owner/moderator who is a partner in an Independent VAG repair workshop, and also a proper tech, assured me that when you replace the "lump" on the earth terminal it is "plug and play".
He has found that in some cases where the battery fails, it can be due to a failed/faulty BMU, so typically he will also replace that "lump" when replacing a failed battery, it seems that some VW Group models were worse than others in this respect, and Polo and its "cousins" are not one of them - I only found that out AFTER buying a new BMU which cost "quite a bit"!
I was only trying to improve the car's ability to keep the battery in "good condition" as I suspected that it was getting over charged - but that EFB battery lasted over 10 years 54,000miles, and I only replaced it with the next size up AGM battery because the car was now over 10 years old AND this AGM battery has been waiting to get fitted into my wife's car for too many years!! I still have not replaced the BMU but after having this bigger AGM battery (coded to the car correctly), fitted for a month or so and having witnessed the charging "characteristics" via a plug in DVM in the power socket, I really should get the new BMU fitted and see if anything changes in respect of the charging "characteristics" .
Cheers pal.
So from your understanding it should be plug and play - hopefully it's the same with a used one, saves about £100, which I'd like to do as it's not worth much being a Cat S car
I was thinking of trying a new battery, EFB but I did do that about a year ago, albeit also a used one via a shop on eBay...
Today my symptoms were less bad, maybe as a result of cleaning the main engine ground up, so will monitor and see.
Actually - I think all it might be referring to in the workshop manual is adapting the J367 to the battery specifications as opposed to adapting the unit itself to the car, think that might be it and I just didn't realise ..
Re: Battery Monitor Unit - J367 Adaptation
Posted: Tue Jan 27, 2026 6:52 pm
by iichel
Yeah like RUM4MO said, it's plug and play, no calibration needed.
Re: Battery Monitor Unit - J367 Adaptation
Posted: Thu Jan 29, 2026 11:17 pm
by RUM4MO
I wonder if it would be beneficial to initiate the "new battery" process after replacing a BMS "lump" - ie change the serial number by one digit, I'll probably try that after I eventually get round to fitting the new BMS "lump" - but only after running the car with the BMS for maybe 7 days without making any changes, while monitoring the charging characteristics/behaviour via the 12V DC DVM plugged into the power socket.
Nothing to be lost by doing that.