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Discussion Starter · #1 ·
Not so much of a problem...the stop start works fine, the question is more to understand its logic!

I understand the system will activate/deactivate itself based on conditions and requirements of the car when in use - heated screens, steering angles etc however I am struggling to understand the logic of a specific "activation" features which have caught me unawares.

Picture the scene I've pulled onto the drive at home, clutch down, into Neutral hand brake on, clutch up engine stops. Faff about picking up some bits out of the footwell, wallet out of the door bin put car in gear, undo seat belt and WOOF there goes the car nearly through the garage door. OK so thats more about habits and sequence - take key out the ignition BEFORE faffing and undoing seat belt (or opening door for that matter).... Lesson learnt. :lol:

Then picture the scene....pull into a busy Garage forecourt, choose a pump and pull up behind pump and wait, stop start kicks in. The guy at the pump seems to be emptying the North Sea oil field into his car and my idle fingers are getting bored so I reset Trip 1 as I'm logging milage and MPG at each fill up. Just as it resets to zero WOOF the car fires into life :eek: . Fortunately not in gear but unexpected none the less.

So it would appear resetting Trip 1 is a condition for restarting the engine whilst stopped under Stop/Start....but why? Whats the significance?! :?:
 

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I tried to replicate this today. Stopped at lights. Car went in to stop mode, reset the trip and car remained in stop mode. Restarted as normal when clutch depressed. Do you think yours needed to restart to have enough power to perform the reset? My stop was very early on my regular journey. Sometimes it will go in to stop mode at the traffic lights, other times it won't.
 

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Picked my Cactus up today, and started playing with things when parked with it in stop mode. After messing around for a little while it restarted. It seems it depends on the state of the battery, once it discharges past a certain point it will restart.
 

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Posted this before but thought would repost about the start stop system

Found an article that is interesting and it seems it doesn't use the starter motor to restart, here is an extract

But there's another, even more advanced version of engine stop-start that you'll find in Peugeot and Citroen cars. The two French companies share parts and use the same system, which makes use of a so-called 'reversible' alternator and capacitors to store reclaimed energy.

The system was introduced to Peugeots by the first generation 308. The alternator can reverse its polarity, switching its function to become a generator and reclaiming energy that would otherwise be lost.

It stuffs the capacitors full of electricity that the alternator then piles back into the engine and restarts combustion in just 400 milliseconds. Once the engine is warm, the alternator takes care of all restarting duties. Like Mazda's system, the fuel savings are immediate when the engine cuts out.

Peugeot estimates that 15% of the time taken for a typical commute is spent stationary, and even includes a dedicated stop-start timer within its models' trip computers so that owners can see the benefit.

This is the article
http://home.bt.com/lifestyle/motoring/m ... 3870847326

Hope it helps
 

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Discussion Starter · #5 ·
Maybe by resting the Trip I was calling upon a system that was not avaliable in Stop mode and hence the restart? For example come to a stop AC will switch off (but fan remains running). During the Stop, enter the fan menu and switch on the AC...I wonder if that starts it up again?

or...

the capicitor bank stores energy for a limited period of time and simply coincided with the pressing of the trip?!

As I say not a huge deal just curious!

JohnC said:
PThe alternator can reverse its polarity, switching its function to become a generator and reclaiming energy that would otherwise be lost.
I have wondered how long it would take for this to filter through. I remember a cold snowy wet damp freezing night when the wife came home and announced "the car wont turn off". Sure enough the dash was lit like a christmas tree and the rectifier was duff...efectivly turning the alternator in a motor. What a fun job that was....

What with modern electronics, improved battery and capacitor tech its interesting to see that this is now a reliable alternative and efficient energy source.
 

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When it goes into stop mode the ac switches off, switching it on starts the car. Now that is annoying when it is 34c outside.
 

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I am sure my A/C stays on in Stop mode. That's why it starts up again very quickly when still waiting at traffic lights because of the power drain on the system.
 

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Discussion Starter · #8 ·
As JohnC mentions the AC switches off when you come to a Stop under a Stop/ Start condition. Whilst the interior fans remain switched on to continue circulating air, the main AC compressor and its anncillary components switches off as these are usually driven from an auxillary belt from the engine.

If you look at the top right hand side of the central screen, when you come to a Stop under Stop Start the "AC" legend dissapears.
 
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