Problem with start/stop system anyone?

[DV52]

So I guess you think that I'm lying. 70,000 miles of driving with it disconnected from the battery with no problems isn't enough proof for you? My dealer thought I was smart to figure out that it could be simply disconnected.

Jim: Most definitely not!! I would NEVER assert that you are telling "porkies". Quite the opposite in fact - I'm certain that you honestly believe that you are correct in your hypothesis.

I have absolutely no problem with anyone holding a firm conviction in their own views- that's their right to do so. It's not my objective to disabuse you of your beliefs - as I said, I'm merely repeating my understanding of the official VW material.

Notwithstanding that your view appears to be at odds with my understanding of the multiple roles of the battery control module - I'm more than happy to entertain the prospect that you have found the "secret key" - well done if this is indeed a viable long-term solution to disable SS - with no side-effects!!

Don

PS: here's an extract from VW's SSP-426 regarding Start/Stop
Battery sensor in battery monitor control unit J367
BlueMotion vehicles with start/stop system
have new wiring to connect the absorbent glass mat
battery including a new battery sensor that is
integrated in the battery monitor control unit.
This control unit is mounted on the minus terminal of
the earth cable and is connected to the diagnosis
interface for data bus via the LIN data bus.
The data obtained allows the charge regulation as
well as the charge voltage to be adapted to the
charge and operating state of the battery.

The SSP goes on to say:
Effect in the event of failure
If the battery sensor is faulty, the operating
condition of the battery can no longer be assessed
correctly.
An entry is made in the fault memory of the data
bus diagnostic interface. The start/stop system is
switched off.

Removing the connector on J367 - simulates a failure in the module with the subsequent effect that "the start/stop system is switched off". So there can be no doubt that SS is disabled - well done!! Incidentally, as also indicated in the extract, a DTC error message is generated in the CAN Gateway module @ address hex19 - because J367 is a LIN slave to this module.

BUT - here's my problem with removing the connector: If J367 is disabled - the SSP clearly identifies that "the condition of the battery can no longer be assessed correctly" (remember, this is a glass mat battery).

And most importantly, if J367 is disabled - how does the bolded bit in the first part of the extract happen? How can the charge regulation/voltage algorithm in the Energy Management facility operate correctly? A rhetorical question, of course - clearly the algorithm can't operate correctly - probably not a big problem in the short term, but not an ideal situation (I suggest) if this solution is used to disable SS in the longer term (again remember, this is a glass mat battery which will be expensive to prematurely replace out-of-warranty).

And finally, incorrect (perhaps "non-optimal" is a better word) charging of the glass mat battery that results from the missing data will have a cumulative effect - IMHO ,"70,000 miles" is not an appropriate metric for judging the real impact of this solution on battery longevity.

So, moral of the story: I can understand if you persist with this solution out of ownership of its discovery! However, please at least consider the stuff above in your resolve to disable SS (which I think is worth doing).

 

[jimlloyd40]

Jim: Most definitely not!! I would NEVER assert that you are telling "porkies". Quite the opposite in fact - I'm certain that you honestly believe that you are correct in your hypothesis.

I have absolutely no problem with anyone holding a firm conviction in their own views- that's their right to do so. It's not my objective to disabuse you of your beliefs - as I said, I'm merely repeating my understanding of the official VW material.

Notwithstanding that your view appears to be at odds with my understanding of the multiple roles of the battery control module - I'm more than happy to entertain the prospect that you have found the "secret key" - well done if this is indeed a viable long-term solution to disable SS - with no side-effects!!

Don

PS: here's an extract from VW's SSP-426 regarding Start/Stop
Battery sensor in battery monitor control unit J367
BlueMotion vehicles with start/stop system
have new wiring to connect the absorbent glass mat
battery including a new battery sensor that is
integrated in the battery monitor control unit.
This control unit is mounted on the minus terminal of
the earth cable and is connected to the diagnosis
interface for data bus via the LIN data bus.
The data obtained allows the charge regulation as
well as the charge voltage to be adapted to the
charge and operating state of the battery.

The SSP goes on to say:
Effect in the event of failure
If the battery sensor is faulty, the operating
condition of the battery can no longer be assessed
correctly.
An entry is made in the fault memory of the data
bus diagnostic interface. The start/stop system is
switched off.

Removing the connector on J367 - simulates a failure in the module with the subsequent effect that "the start/stop system is switched off". So there can be no doubt that SS is disabled - well done!! Incidentally, as also indicated in the extract, a DTC error message is generated in the CAN Gateway module @ address hex19 - because J367 is a LIN slave to this module.

BUT - here's my problem with removing the connector: If J367 is disabled - the SSP clearly identifies that "the condition of the battery can no longer be assessed correctly" (remember, this is a glass mat battery).

And most importantly, if J367 is disabled - how does the bolded bit in the first part of the extract happen? How can the charge regulation/voltage algorithm in the Energy Management facility operate correctly? A rhetorical question, of course - clearly the algorithm can't operate correctly - probably not a big problem in the short term, but not an ideal situation (I suggest) if this solution is used to disable SS in the longer term (again remember, this is a glass mat battery which will be expensive to prematurely replace out-of-warranty).

And finally, incorrect (perhaps "non-optimal" is a better word) charging of the glass mat battery that results from the missing data will have a cumulative effect - IMHO ,"70,000 miles" is not an appropriate metric for judging the real impact of this solution on battery longevity.

So, moral of the story: I can understand if you persist with this solution out of ownership of its discovery! However, please at least consider the stuff above in your resolve to disable SS (which I think is worth doing).

Thanks for posting that. I don't remember who originally mentioned that the dealer warned him about that but it is only for the few models that are Bluemotion equipped. And in reading that those vehicles wouldn't want to disconnect the start/stop from the battery. That's not relevant to the GTI which I was referencing. Only Bluemotion vehicles. So if the person whose dealer told him that it was true if he has Bluemotion. If he doesn't have it then it's not relevant.

 

[Carlosfandang0]

Thanks for posting that. I don't remember who originally mentioned that the dealer warned him about that but it is only for the few models that are Bluemotion equipped. And in reading that those vehicles wouldn't want to disconnect the start/stop from the battery. That's not relevant to the GTI which I was referencing. Only Bluemotion vehicles. So if the person whose dealer told him that it was true if he has Bluemotion. If he doesn't have it then it's not relevant.

I’ve no idea about other markets, but my UK GTi Uses the (BMT) bluemotion technology brake energy recuperation system!

 

[DV52]

Thanks for posting that. I don't remember who originally mentioned that the dealer warned him about that but it is only for the few models that are Bluemotion equipped. And in reading that those vehicles wouldn't want to disconnect the start/stop from the battery. That's not relevant to the GTI which I was referencing. Only Bluemotion vehicles. So if the person whose dealer told him that it was true if he has Bluemotion. If he doesn't have it then it's not relevant.

Jim: As I said - it is not my purpose to disabuse you of your beliefs.

If you cling to the word "Bluemotion" and if you assert that in your car, J367 doesn't have the multi-purpose that is described in VW's SSP - then with the greatest of respect and with no ill intention meant - I have only one final observation to make: there is no greater folly than someone who believes that truth has only one face.

Don

 

[jimlloyd40]

Jim: As I said - it is not my purpose to disabuse you of your beliefs.

If you cling to the word "Bluemotion" and if you assert that in your car, J367 doesn't have the multi-purpose that is described in VW's SSP - then with the greatest of respect and with no ill intention meant - I have only one final observation to make: there is no greater folly than someone who believes that truth has only one face.

Don

I don't know what J367 or VW'sSSP stands for. I have an 18 GTI SE and I disconnected the stop/start from the side of the battery 70,000 miles ago without problems. I read the bulletin that you posted and it is related to the cars that have Bluemotion which mine does not.

 

[Tdiguys]

Has anyone had any problems with start/stop on their Mk7's?

Earlier this week, I stopped due to traffic. The start/stop system shut the engine down as usual but when I came to move off, the engine failed to start. The starter attempted to restart the engine but it misfired and just died.

The MFD showed a message like “manual engine start required”. I tried three times to start the engine with the key – each time, it turned the starter but the car just would not start.

"ACC unavailable” then lit up, along with a yellow ACC warning symbol.
I turned the key right off, waited a bit - only then did the car start.

Really not great thing to happen - the dealer and VW UK don't seem interested even though some DTCs were logged.. Still trying to find out from the dealer exactly what they were..

-AG

Well the thing is with stop start systems how often are you using it ? When your engine turns over and cranks constantly believe it or not it wears your engines life out doing so I mean that’s if you literally are doing it every minuet , now that’s just a general opinion but your starter motor has a life of its own it’s prob just your starter motor or you say you had a misfire it’s possible that it could just be loose spark plugs or worm spark plugs , Vw are complex vehicles with lots of sensors so might be worth checking even that. Check for codes if your mentioning a misfire could be somthing tiny or could Leed to other issues if you don’t get it checked pal

 

[Tdiguys]

C

Same issue here too on my 2013 1.4 TSI DSG. I managed to capture it on video luckily. It only happens about 1 in 10 times.

- Pull up to some lights
- Car stop/start system shuts the engine off as expected and the auto-hold system put the green P indicator on as normal
- Press the accelerator to set off and the engine fails to start (You can see in the video it reached about 500 revs)
- Take foot off the accelerator completely and back on a second time and it starts and drives off without an issues

https://photos.app.goo.gl/2Vk5XCJwXud3thH5A
Any thoughts or anyone have a similar issue?

check my comment on the original post

 

[DV52]

Same issue here too on my 2013 1.4 TSI DSG. I managed to capture it on video luckily. It only happens about 1 in 10 times.

- Pull up to some lights
- Car stop/start system shuts the engine off as expected and the auto-hold system put the green P indicator on as normal
- Press the accelerator to set off and the engine fails to start (You can see in the video it reached about 500 revs)
- Take foot off the accelerator completely and back on a second time and it starts and drives off without an issues

https://photos.app.goo.gl/2Vk5XCJwXud3thH5A
Any thoughts or anyone have a similar issue?

-ton: Intermittent problems like that one that you describe are difficult to diagnose - but I'm not sure if you are aware that your mk7 actually tells the driver why Start/Stop has not operated correctly (if it wasn't disabled with the native SS kill switch on the console).
The next time that your problem occurs - press the SS message on the MIB screen - as shown below (apolgy for the dirty camera lens):

After you do this, you will be presented with the following screen:

• Listed on this screen will be all of the reasons why SS has been prohibited from operating correctly (and there can be lots of reasons)
• notice that some entries have a "human head" on the extreme left-side. These are the factors that have prohibited SS - but that are in the control of the driver
• notice that the first entry doesn't have the "human head" -so this reason is caused by sensor(s), or algorithms in the Energy Management system. In this particular case, the Power consumption is high entry was caused by disabling SS with a VCDS cable using the "temperature" method. The exact same reason happens if the VCDS tweak is implemented using the "voltage method"

As I said, the next time your SS function doesn't operate correctly - I suggest that you look at this screen. It might at least tell you the general area that is causing the problem.

Don