Auto Stop-Start disabler!

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Astra Model: RS 1.6T
Astra Colour: Silver

Auto Stop-Start disabler!

Post by AussieKOwner » Wed Feb 19, 2020 2:02 am

So ever since I have had the K, the most annoying thing (well, one of the really annoying things) is the Auto Stop-Start. It's overactive and would save me less than $2/month so the extra wear on engine components is just not worth it.

I hate the feature and turn it off every time I start the car but sometimes I forget.

I came across that gives design files etc for a Attiny13 based device that simply presses the button every time the ignition is turned on. I had a couple of shots at making one but for some reason I could not get it to work (I have a healthy electronics background). Not saying the device is not any good, just the versions I made of it did not work.

He has some very tight constraints over usage so you can't buy a pre-made version of it.

So, I thought bugger it, I'll make my own version.

I used an arduino pro micro (Atmega32u4) but you could use a Pro mini or whatever you want (if i did it again I'd use the Pro Mini, plain Atmega32 but it's just what I had laying around)

Disables the SSA by 'pressing the button' about 6 seconds after the car is started.
Enable/Disable function - Can be disabled by holding the button on ignition turn on
Beeper (optional) so you get an audible sound when enable/disable the module and also when it presses the button.

The Schematic is based on the German version but it is my custom code.

Total cost should be about $10-$15 and some of your time to make yourself.

Simple components:
10K Resistor
1k Resistor
5v Voltage regulator (capable of 15+v input, ie 7805 or module)
BC548 Transistor
BAT4x Diode

To install, you need to remove the buttons and solder to wires for Pin1- black (ground) and pin 4 - Grey (SSA button) and find power in the fuse box - There are only a couple that have ignition based power.

Video of it working

I am happy to post the exact detail and code for making your own but that will take a little time. I will also consider producing/selling these pre-made or kits (with proper circuit boards) for cost price if there is enough demand.

*Also compatible with any other negative switching SSA enabled cars.

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Re: Auto Stop-Start disabler!

Post by MisterEChops » Wed Feb 19, 2020 10:56 pm

I've gotta ask... Why would you go to all this effort?

It takes literally only one button press when you get in to the car already

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Astra Model: SRI, 1.6 CDTI (136), 2016 plate
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Re: Auto Stop-Start disabler!

Post by Rob14 » Wed Feb 19, 2020 11:41 pm

I don't understand why people are so against start stop. I use it when ever I'm going to be stationary for a period of time or long time at traffic lights. I think it's good and cuts on fuel and emissions.

I don't know if it works differently in an automatic but getting something to delete it seems like an unnecessary expense and waste of time. Would that also not affect the resale cost?
SRI, 1.6CDTI, 136bhp, 2016 plate, Manual, Grey,

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Astra Model: RS 1.6T
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Re: Auto Stop-Start disabler!

Post by AussieKOwner » Thu Feb 20, 2020 1:05 am

Well it just grinds me. Everything I know about cars (and being a little old school) is that stopping and starting constantly is bad, even more with a turbo. Heat cycle stress, battery wear, turbo bearings (even though these are roller ball), starter wear etc.

Castrol even done a whole marketing campaign on the fact that xx% of engine wear happens at startup which was their reasoning for 'magnatec' oil. It has to have some effect as it takes a few moments for the oil pressure to come up. Yes, it's super short but not non-existent.

Not only that, the overactiveness of the SSA is crazy. In winter at <10 degrees c, I can start a cold car, drive 20m and it will stop again. That is just crazy. I've also had instances where it has kicked in, causing a dangerous situation - It stopped as I went to take off pulling into traffic!

Then again, It may have no impact at all, and while the car is under warranty and you have no intention of needing to have it last you wouldn't care. The fact is, we will not know the impacts of this until the cars reach later in life.

My commute is ~25min to work. Of that, ~15min is freeway so I spend very little time stationary and when I do it probably totals 5min or less. At ~0.8lh means I save ~$0.1 per commute if it was on. That can no way be worse than having to replace a battery or starter. So to claim it has a cost benefit, or even the negligible environmental benefit in my case is pointless.

My personal opinion is that resale price would be higher because of this, not lower but each to their own.

I went to the effort because I could....

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Astra Model: SRi Nav 1.6 CDTi S/S (136bhp) Hatchback
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Re: Auto Stop-Start disabler!

Post by Vayerr » Thu Feb 20, 2020 9:11 am

Stop Start is beyond fkn annoying and never worked properly for my Astra or any of my dads cars and he had a few. Every car should have a built-in feature to permanently disable it without having to press the button.

Good job on making this.

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Re: Auto Stop-Start disabler!

Post by Tiberius » Thu Feb 20, 2020 9:20 am

In the UK the Highway Code states that when stationary you should apply the handbrake (to minimise the glare to the driver behind) and to put the car in neutral. This causes my automatic to re-start the engine so voiding any benefit of the S/S.

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Re: Auto Stop-Start disabler!

Post by Finston Pickle » Thu Feb 20, 2020 7:07 pm

Does anybody know what extra mileage stop/start typically gives?

As my Astra ST does 44.6 mpg since new, without using S/S, I always switch it off.

I totally agree that S/S probably does not significantly help emissions, save fuel and is bad for the engine generally.

On the plus side if you switch off S/S you have the benefit of a heavier duty starter motor being run at a lighter duty cycle, a bigger battery than what you would otherwise have (again heavier duty cycle by design, but lighter use than design in practice) so starting reliabilty should be better than before S/S was thought of.
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Re: Auto Stop-Start disabler!

Post by astraowner » Thu Feb 20, 2020 8:22 pm

The reason cold starts are bad, is that the oil needs to travel around the engine.

Stopping the engine for 1 minutes, does not drain all the oil down into the sump and also, when the engine is at running temp, starting is not very wear heavy.

The reason for S&S from what i have read, is mostly to stop the engine in the cities. Even if the saving is very little, a lot of very little savings, goes a long way to improve the air quality in the cities.

I always let the car stop the engine.

If you dont want it to stop, atleast on the diesel, all you need to do is keep the clutch pedal down, this will make it not stop.

I usually do this if i come to a red light and i can see that it is just about to change to a green within 5 seconds.
2016 Astra K 110HP, Opel Eye camera, front and rear parking sensors, dual zone climate control and heated front seats, sight and light pack.

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Re: Auto Stop-Start disabler!

Post by AussieKOwner » Thu Feb 20, 2020 9:25 pm

Definitely a split crowd!

I know having the clutch depressed prevents it stopping but that is bad for long durations too. Thrust bearing and still clutch wear (the clutch does not completlely release from the friction surfaces).

I didn't know that having the handbrake on prevents it. I knew door and bonnet do.

Mileage/fuel gain is dependent on how long you're sitting stationary in traffic. My car averages between 0.6 and 0.9 l/h so calculate from that.

Mazda's trip computer tells you how many litres you have saved over the life of the car.

Either way, its personal preference.

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Re: Auto Stop-Start disabler!

Post by Crosseyxpower » Thu Feb 20, 2020 9:46 pm

The rule of thumb that has been tested for small engines and large is that s/s will only start saving you money and fuel if the duration of the engine idling is around 6-7 secs for both petrol and diesel. So, if you can predict that at a certain set of traffic lights you'll be stationary for more than 7 seconds waiting for them to go green then it's pointless activating s/s. As for wear and what not then I'm sure that's minimal over a typical owners duration of ownership of a few years. The main objective of s/s was to reduce emissions, so yet again 6-7 seconds then it is achieved, if not then it's actually more polluting. The main reason for manufactures doing s/s was to decrease the taxation on cars and car tax over ownership. £20 a year for my astra is a bargain compared to most other cars on the road that are even more fuel efficient and cleaner with them paying £145 now. As soon as the taxation on cars emissions changed, so did the amount of new cars being sold!

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