Stop Start on 981 has a mind of its own
Discussion
Does anyone know the parameters or algorithms that stop start uses, as its operation seems totally sporadic.
In every car I have driven (beside Porsches) the stop start its operation is consistent and the engine can be stopped for minutes at a time.
Sometimes it works in my Cayman but sometimes it doesn't, I know its influenced by battery voltage, ambient temperature and electrical load but I can't seem to figure out a pattern for it working.
For example; driving at 70mph for an hour then coming off the motorway and stopping at a red light, it won't work. Strange as you would think the battery would be fully charged.
On the contrary, start the car and turn the A/C off, drive up to the gate to exit the work car park and despite the cold engine the engine stops while I wait for the barrier.
Also when it does work sometimes its only for 5 seconds and sometimes longer, the longest its ever worked is 60 seconds.
In every car I have driven (beside Porsches) the stop start its operation is consistent and the engine can be stopped for minutes at a time.
Sometimes it works in my Cayman but sometimes it doesn't, I know its influenced by battery voltage, ambient temperature and electrical load but I can't seem to figure out a pattern for it working.
For example; driving at 70mph for an hour then coming off the motorway and stopping at a red light, it won't work. Strange as you would think the battery would be fully charged.
On the contrary, start the car and turn the A/C off, drive up to the gate to exit the work car park and despite the cold engine the engine stops while I wait for the barrier.
Also when it does work sometimes its only for 5 seconds and sometimes longer, the longest its ever worked is 60 seconds.
Bennachie said:
First thing I do after starting the car is........ turn it off.
Wish we had the US of A option for it to remember what mode it was last in. Reverting to 'on' is a pain.....
On the likes of the motorway I don't mind it, but yes in a busy town with roundabouts etc. the car stays in sport mode.Wish we had the US of A option for it to remember what mode it was last in. Reverting to 'on' is a pain.....
I had a diesel Panamera for a week which I did a few hundred miles in and I couldn't get that to work full stop, the stop sign symbol was always displayed yellow - so the system knew it should deactivate.
Yes I have the voltage meter but it never shows anything out of the ordinary.
Car is almost 4 years old but you are probably right, the s
tty Moll battery is probably to blame.
I wonder how it would work with a decent Bosch example. My friends Mondeo will stop for several minutes at a time, providing a genuine fuel saving at stubborn traffic lights or jams.
Car is almost 4 years old but you are probably right, the s
tty Moll battery is probably to blame.I wonder how it would work with a decent Bosch example. My friends Mondeo will stop for several minutes at a time, providing a genuine fuel saving at stubborn traffic lights or jams.
NAS90 said:
From memory it works of several parameters but if the car is in Sport + it won't turn off at all.
Likewise if the engine oil is hot (having been driven hard), battery voltage is low or high demand on electrical system, HVAC system demands also affect whether the engine shuts down or not.
Personally it is the first button I push in any car when I start it up, i like the engine to run until I turn it off myself.
Those are true but my point is its operation is appears random, e.g. same commute every day and different results with start stop.Likewise if the engine oil is hot (having been driven hard), battery voltage is low or high demand on electrical system, HVAC system demands also affect whether the engine shuts down or not.
Personally it is the first button I push in any car when I start it up, i like the engine to run until I turn it off myself.
It is a very strange piece of kit on Porsches.
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