Stop Start not working even after new battery. Help!

[Black300ST]

Hi.

Some techy help needed please.

Bought my car last week and the stop start wasn't working. Presumed it must be the battery so changed it, but the fault is still there.

The infotainment system says "consumption is high" but it does that even with everything that is a drain turned off.

Any ideas???

 

[RUM4MO]

Well, first thing, which type and size of battery did you remove and which type and size of battery did you replace it with?
Second, is the small flying lead connected to the BMS dongle that is part of the earth lead at the battery?
Third, did you code in the new battery to this car?

 

[Black300ST]

Well, first thing, which type and size of battery did you remove and which type and size of battery did you replace it with?
Second, is the small flying lead connected to the BMS dongle that is part of the earth lead at the battery?
Third, did you code in the new battery to this car?

Thanks for the reply. The local garage did the battery swap. It's a Bosch S4 E08 70Ah. Yes the flying lead is connected but I'm not sure if they coded the battery. I imagine as a garage they must have done these before, so I would imagine they did.

What's involved in doing that? Is it something I can do or check?

I'm wondering if the previous owner may have turned off the stop start with an OBD plug in or something like that?

 

[adam davies]

Thanks for the reply. The local garage did the battery swap. It's a Bosch S4 E08 70Ah. Yes the flying lead is connected but I'm not sure if they coded the battery. I imagine as a garage they must have done these before, so I would imagine they did.

What's involved in doing that? Is it something I can do or check?

I'm wondering if the previous owner may have turned off the stop start with an OBD plug in or something like that?

Happy days if stop start is not working. Less stress on battery, starter motor, alternator and engine.

 

[RUM4MO]

It sounds like they fitted a correct aftermarket equivalent battery ie an EFB one.
You can't check anything to see if they recoded the car to recognise that it has a new battery, all you could do, if you had a proper VW Group compliant diagnostic tool, would be to check the battery stats to see if they looked like the battery was replaced with a new one recently.
I think, that with time, the car's battery charge management system will adapt itself to be optimised to that new battery's improved health, so maybe wait a few weeks and see if things improve.
I would hope that any car garage that replaces car starter batteries in Stop/Start car knows that the new battery needs coded into that car.
There is just one other issue, if the BMS dongle that is on the battery -VE post is not doing what it should, then maybe that is what killed the previous battery and will go on to force the new battery to an early demise.
I plan to replace the EFB battery in my wife's August 2015 VW Polo with an AGM "sometime" ie after it hands out its first "I'm not too well" message, I have bought a new BMS dongle to fit at the same time, unfortunately these BMS dongles cost quite a bit, but there again so does replacing the car's battery every year!
I bought a cheap plug in 12V DC digital meter, and it lives in the front power socket, so that I can keep up to date with battery charging.

 

[Black300ST]

Happy days if stop start is not working. Less stress on battery, starter motor, alternator and engine.

But seeing as I spend most of my life in traffic these days, it's not very good for fuel consumption.

 

[Black300ST]

It sounds like they fitted a correct aftermarket equivalent battery ie an EFB one.
You can't check anything to see if they recoded the car to recognise that it has a new battery, all you could do, if you had a proper VW Group compliant diagnostic tool, would be to check the battery stats to see if they looked like the battery was replaced with a new one recently.
I think, that with time, the car's battery charge management system will adapt itself to be optimised to that new battery's improved health, so maybe wait a few weeks and see if things improve.
I would hope that any car garage that replaces car starter batteries in Stop/Start car knows that the new battery needs coded into that car.
There is just one other issue, if the BMS dongle that is on the battery -VE post is not doing what it should, then maybe that is what killed the previous battery and will go on to force the new battery to an early demise.
I plan to replace the EFB battery in my wife's August 2015 VW Polo with an AGM "sometime" ie after it hands out its first "I'm not too well" message, I have bought a new BMS dongle to fit at the same time, unfortunately these BMS dongles cost quite a bit, but there again so does replacing the car's battery every year!
I bought a cheap plug in 12V DC digital meter, and it lives in the front power socket, so that I can keep up to date with battery charging.

Thanks for the reply. The old battery seemed ok actually, the car started no problem. I think I may have binned a perfectly good battery just on the assumption that it was the cause of the issue. The car is going back into the garage next week so I'll double check they coded it like they should. I'll get them to check out the dongle thingy too. I have a funny feeling though that stop start has been programmed out by the previous owner.

 

[SteveGSXR600K1]

But seeing as I spend most of my life in traffic these days, it's not very good for fuel consumption.

The stop/start systems are designed to reduce emissions when sitting in traffic, not to improved MPG.

 

[Black300ST]

The stop/start systems are designed to reduce emissions when sitting in traffic, not to improved MPG.

So if I'm in traffic with the engine off I'm not going to use less fuel than with it running? Emissions come from the burning of fuel don't they? So if it reduces emissions then it's obviously using less fuel???

 

[BigJase88]

The previous owner may of coded out the stop start.

I coded mine out on my Audi A3. Basically change parameters so that the car is looking for a higher voltage threshold before turning off.

The fuel used ticking over is negligible. I think on my Mercedes it was something like 0.91l per hour to tickover.

 

[Black300ST]

The previous owner may of coded out the stop start.

I coded mine out on my Audi A3. Basically change parameters so that the car is looking for a higher voltage threshold before turning off.

The fuel used ticking over is negligible. I think on my Mercedes it was something like 0.91l per hour to tickover.

Yes I think that's what's happened. The previous owner may have coded it out. My last car (Audi Q5) had it though so I'm kinda used to it and it feels weird that it doesn't kick in when it should.

Yeah I know it only uses a small amount idling, but I bet over the year and if you do a fair bit of mileage it adds up.

 

[oldglosracer]

Always best to read the fault codes to see of there is an error, before playing 'Parts darts', as you say you may have binned a perfectly good battery.

The stop start is very keen, even on these cold mornings when the engine is barely warm, mine turns off at a junction whilst I wait my turn.

 

[Black300ST]

Always best to read the fault codes to see of there is an error, before playing 'Parts darts', as you say you may have binned a perfectly good battery.

The stop start is very keen, even on these cold mornings when the engine is barely warm, mine turns off at a junction whilst I wait my turn.

Parts Darts lol. I like that one! I really need to get a fault code reader to be honest.

Yes I just want it working. It's just annoying that it should work and it doesn't.

 

[RUM4MO]

This is the issue with people making changes to their cars and then moving them on, maybe there should be a "return to factory settings" option that ALL traders should perform before re-selling cars. It becomes their fault when they offer up these cars for re-sell, make them work a bit for their money, surely not too much to ask of a legitimate car trader!

 

[BillyCool]

Parts Darts lol. I like that one! I really need to get a fault code reader to be honest.

Yes I just want it working. It's just annoying that it should work and it doesn't.

A Carista dongle and the Carista app are quite good for basic fault finding. You can also use it to turn on/off stop start.

 

[RUM4MO]

A Carista dongle and the Carista app are quite good for basic fault finding. You can also use it to turn on/off stop start.

Sorry, I was about to misjudge you there, ie when you suggested that Carista could be used to turn off stop start, but I can see that you meant that Carista could be used to "switch on" auto stop/start again - if it is that that is the root cause of the problem.

I have Carista on my iPhone and a Carista dongle in each of our cars, second dongle bought very cheaply on a Black Friday deal, so we're covered for any warnings appearing when "out and about" - and VCDS for when at home!

 

[BillyCool]

Sorry, I was about to misjudge you there, ie when you suggested that Carista could be used to turn off stop start, but I can see that you meant that Carista could be used to "switch on" auto stop/start again - if it is that that is the root cause of the problem.

I have Carista on my iPhone and a Carista dongle in each of our cars, second dongle bought very cheaply on a Black Friday deal, so we're covered for any warnings appearing when "out and about" - and VCDS for when at home!

LOL! That's fine. Yeah - was suggesting that it is a way to check if it's been turned off in the settings and be able to turn it back on.

Since you have Carista and VCDS, you seem to have it covered.