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Post by sandertsi on Apr 27, 2024 16:53:56 GMT
When we use the voltage method to enable or disable start/stop these numbers are mentioned:
12.1v (disabled) /// 7.6v (enabled)
I own a 2019 Bluemotion mk7.5 TSI with DSG gearbox. This is equiped with the additional lithium battery under my seat to allow engine off coasting. This is part of the economy tricks to get better milage and it takes some getting used to.
When I disabled this feature by setting it to 12.1v, mine was set to 7.8 originally instead of 7.6v seen elsewhere as original value.
What would explain the 0.2v difference? Is it because of the engine off coast requiring an additional buffer? Tweak by the dealership on customer request from previous owner? Curious to why there is a variance on the OEM voltage number and if anyone on here knows what effect that little variance means in real world driving.
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Post by vwjap on Apr 27, 2024 22:23:01 GMT
Might of brought it up by .2v because more and more electronics are fitted to cars
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Post by dv52 (Australia) on Apr 28, 2024 0:54:07 GMT
hmm......... maybe vwjap is correct (I don't know). However, there are many re-requisites for SS to operate correctly - including the presence of a T15 voltage (meaning ignition-ON) and NO forward speed (meaning the car must be stopped). Both of these do NOT change when an " additional lithium battery under my seat" is installed.
AFAIK, the significance of 7.6 V has never been explained officially in any VW/Audi material. Personally, I do NOT believe that the voltage value is significant (and certainly not to the first decimal place)- my hunch is that 7.6V is simply a ludicrously low threshold value that is used by the SS decision algorithm. I do NOT believe that the value is the actual battery rail voltage on the car because changing the value to somewhere near 12.1V disables SS. I suspect that the SS algorithm must be sensing this voltage somewhere electrically well-downstream of the normal T15, or T30 supply points - I think.
0.2V on a 7.6V base is about 2.6% = not much for a threshold value!!
Don
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Post by sandertsi on Apr 28, 2024 11:53:02 GMT
I’m leaning to vwjap’s hunch. That battery under my seat allows start/stop to function during driving between 130 - 40 km/h. It restarts the car by the starter, clutches or a combination. Being unable to restart standing still at a light is less dangerous as to when going down an offramp with engine cut at 110 km/h. So it just might make it a little more conservative? Here is a nice overview of the system:  |
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Post by harryvw on May 29, 2024 18:25:04 GMT
Hi all,
If a may in addition to the question above;
I own the same car with 1.5TSI - 150ps. I've set the voltage level to 12V but SS keeps working. The setting before was 12.1V and SS also kept working.
What can I do to make sure the SS system is disabled as it's, next to the coasting function, pretty annoying.
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Post by dv52 (Australia) on May 29, 2024 21:42:42 GMT
Harry: Hi. I'm not really familiar with the "1.5TSI - 150ps" - but as I understand, this car has an "evo" engine and it appears be the forerunner for the eventual MQB-evo platform that underpins the later Golf Mk8 models (I'm guessing).
My hunch (at least in respect of the engine in this car) is that the reason why the "voltage method" for the Start Stop (SS) tweak doesn't work might be the same reason why the tweak doesn't work on mk8s!
So, I suspect that the ONLY other alternative to disable SS on this car might be the non-coding method- meaning installation of an electronic switch that mimics the driver pressing the SS-off button. I'm not sure if a AUTO SS kill-switch is made for this engine - but I suggest that you search Mr Google
Don
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Post by vwjap on May 31, 2024 19:02:25 GMT
Hi all, If a may in addition to the question above; I own the same car with 1.5TSI - 150ps. I've set the voltage level to 12V but SS keeps working. The setting before was 12.1V and SS also kept working. What can I do to make sure the SS system is disabled as it's, next to the coasting function, pretty annoying. Pretty sure 2019 is when VAG stopped the voltage method of deleting start/stop, |
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