In various threads I've read things like:
"... as software adopts to your driving style ..."
"software is still learning ..."

I am curious as to what exactly the software is trying to do. (I suppose this is a question about modern car software in general, so pardon me if this is posted in the wrong place!)

Thanks for any input! :smile:

 

Mini head technician told me that the service milage counter changes based on how you drive. if you punch it a lot, the milage goes down a bit cause you drive your car super hard.


Also, im not sure if MINI has this, but ive heard in BMW's the software changes the throttle based on how hard you drive. If it knows you like to shoot off the line, it gives more gas when you put pedal to the floor.

 

I've heard the same things.Another reason to not let the car sit idling,it may learn to only do that

 

It's based upon the amount of fuel you run thru the car. So the more fuel efficient you are, the higher the number of miles prior to service.

 

I can understand the computer telling you to get your next service sooner based on driving habits (driving with revs higher means sooner service). BUt this thing about it learning that you like to 'shoot off the line' and therefore giving you more gas when you hit the pedal is kinda scary. Suppose I really need the gas (in an emergency) but the computer is saying "he's never done THAT before; must be a mistake; I'm not giving him the gas"

I'd better start 'shooting off the line' more often!:smile:

 

I was wondering why my miles to service was less than it should be between 10k and the miles it has on it....

Yeah I like to romp on the gas every single time...

 

I tend to think I drive the car on the harder side. however with ~4400 miles the service indicator is reading 6200 miles. So maybe I should push it a wee bit harder. Although it has been rather cold here lately so pushing the RPMs too soon wouldn't be that smart of a thing to do.

 

Here are a couple of quotes from threads I came across today:

"The ecu is learning the new set-up now that I have about 350mi on it." - El Diablito (probably not stock software, still ...)

"So, here are my questions. How do I keep it this way? I don't want the ECU to 'learn' to do anything different." - brgfan

Can anyone knowledgeable about the software explain to me what it is trying to optimize or 'learn' ?

 

Here is another quote:

"I'm sure after being broken in, and once the computer adjusts to your driving style, this wouldn't be an issue. Both were in a totally different league to my MC."

So, what's going on folks? What is the computer trying to "adjust to"? There must be someone on this forum who has dealt with the MINIs software to say something about this?

 

Ok a lot of what people are talking about in those quotes is the computer addapting to mods they have installed.

Most all engine mods are going to increase the air flow potential of the engine. The computer needs to compensate by adding more fuel to match the new air flow potentials.

By adding say a open element, Hot air intake or some other mod you are making it easier for the engine to breath. Now right away the engine will probably make some more power but as you drive the car the computer will learn how much more air it has to work with.

As you drive more the engine computer will adapt by measuring the air flow at all rpms and the more it learns it will more accuratley apply more fuel, adjust spark timing, advancement etc.

After doing a major mod the car may idle a little higher or idle differently but after a few days the computer will adjust and probably run better then before the mod.

This is true of cars that have Mass Air Flow dependent computers. Some older fuel injected cars use a system called Speed Density which is not capable of adjusting to mods like a MAF equiped car is.

Speed Density cars use Air to fuel ratio charts to calculate fuel quantity levels for various RPMS and ambient temps.

 

I was told by someone at the MINI plant in Oxford (a question during the factory tour)... that the ECU does infact *learn* both your driving habits and adapts to the fuel you put in it.

Thus the fuel mappings are different for 89, 91, 93 (,96?) octane gasoline.

There is a way to get into the ECU system (pressing ODO reset while turning key to position 1). one of the tests performs a software reset, this would allow your computer to re-learn any bad habits, but is also useful after you "mod" your car. I reset mine this winter so it would adapt to the colder denser air thus readjusting the air/fuel mixture... seems to have worked, my range reads 433 miles-per-tank at each fillup (actually getting 390 on 12.5gal).

 

There is no way for the computer to tell what ocatane gas you are putting in the car.

They don't have sensors for that yet and so the fuel system is calibrated to run on 93 octane or 91 octane if the car is sold in california.

Unless the MINI is a 50 state car which i think it might be then it is just calibrated to run on 91 ocatane and 93 octane is just insurance.

Now if you got a custom flash down to your ECU you could have the timing adjusted to take advantage of say 96 or 100 plus octane fuel. You would need to be running enough boost and/or compression ratio to need the higher octane though.

Higher octane fuel does not create more power. The octane rating is just a rating of the fuels ability to prevent pre-ignition from super hot combustion chambers. You need to run the higher octane when on big boost to keep the fuel from pre-igniting as it enters the super hot combustion chamber and causing detonation.

 

Thanks for the input! Having the software adjust the air-fuel mixture after some mod (or simply adjusting to the quirks of the particular car) to optimize combustion is easy to grasp. I am having a problem though understanding this "adjusting to driving style" and "learning driving habits" thing. I am really curious what it might be monitoring about your habits and what it does with that information. (Maximize power? Fuel efficiency? Anything else? Under what input from the driver?)

 

All ecus have "default" tables in them for air to fuel mixture, and ignition timing (after 1996). These are used when the engine is in "open loop mode" which means the oxygen sensor is still cold, or the engine is running at high output levels in excess of the ability of the oxygen sensors to supply reliable data. The ECU tuners adjust the values in the high ouput range areas of the tables.

In closed loop mode, the ecu "learns" the proper air fuel and timing advance levels for current conditions, based on the oxygen sensors readings, and the knock sensors.

As for octane. The engine is protected by anti knock sensors, which is how it learns the fuels resistance to preignition. The higher the octane, the more resistant to preignition. The engineering paper says you can "Safely" put any gasoline available world wide in the car, but it is optimized for 98 (European method) octane.

What we don't know is what triggers a "re learn" to better fuel.

For example. On one GM car, if the engine knocks, the ecu will adjust until the knocking stops, and will keep running on this "learned" level until it sees the fuel tank go below 1/4 then fill above 3/4. It will then try pushing the advance up again until if finds the knock limit for this tank of fuel.

The MINI might do it this way, or maybe it periodically trys the timing, or ??

Several folks have suggested filling with 100 octane for at least one tank and driving aggressivley before going to a track event, if you expect maximum power.

It is a 20 mile trip for me to get 98 to 100 Octane fuel, so I would like to know if I should make that trip a week a head of time, or just fill up on the day I want maximum performance.

John

 

Thanks for the info! The software using the tables for a/f ratios and ignition timing with input from the oxygen sensor makes perfect sense. Where does 'driving habit' come in though?

 

I would expect that, in part, some of the data is provided by the throttle position sensor and the DME reporting throttle angle versus rpm. Just a guess, though...

Theo

 

Let's put it this way: Suppose we have two identical MINIS and each one is driven quite differently for some time (to give them time to "learn" that driver's habits, if in fact that happens). One is driven like a bat out of hell all the time , and the other like it was the lead car in a funeral procession. Then after this initial period, they are driven the same way. Would the cars 'behave' or respond differently under the same conditions of input from the driver?

 

I say give me 2 MINIs and I'll give this a go
Cause I ain't driving mine either way all the time

 

Yes.

The "bat car" will have adjusted to the more agressive driving style by ensuring that the adaptive portion of the mapping creates an A/F mixture that more optimally supports a wide open throttle (WOT) situation. Thus, the adaptive settings will be biased toward the performance end of the spectrum.

However, the "funeral car" will have been driven modestly with very few WOT situations arising. The adaptive portion will then "dial-back" its A/F settings to optimize fuel usage. This would bias the adaptive settings toward the economy end of the spectrum.

It is also important to note that the adaptive settings never stop adapting. When you reset the ECU, you start with a "base" value for these settings. Then, as you drive the car, the adaptive process process begins and continues to adapt settings until the next time you reset the ECU.

Theoretically, this would mean that if the "funeral car" were to be driven with a high percentage of WOT for 300-400 miles, it too would eventually adapt its settings from the economy toward the performane end of the spectrum. The reverse would be true of the "bat car" if driven in an extremely conservatiove manner.

I do not have any detailed data to support the following assumption, but I believe the rate that the adaptive settings change the most occurs between an ECU reset and the first 300-400 miles. After that, small adjustments are continually being made, but not at the same rate as after an ECU reset.

There is some logic in this assumption if I am correct in my guess that the adaptation process continually checks the the difference between the adaptation settings currently in memory and the "averaged real time" data that may indicate an adjustment is necessary. There will be a bigger difference between the "base" values produced at ECU reset and "averaged real time" data. Thus, the magnitude of each adaptive change will be greater because of this difference. However, just changing drivers or driving style may not produce the magnitude of difference to reproduce the rate of change found after an ECU reset.

This is one of the reasons that I am a big fan of ECU resets after any ECU change or performance modification. Following this logic, one might want to reset the ECU for other reasons as well:

1. You have acquired a used MINI;
2. You have made modifications (CAI, TB, Pulley, Header, Exhaust, etc.);
3. You have large seasonal swings in temperature or gas formulation;
4. You get to drive the spouse's MINI for the next month or so ;
5. You get a kick out of the lights flashing on the dashboard .

Again, I do not have any data to back up my assumption...just the feel of the car. It would be interesting for someone (much more technical than I) to delve into the detail operation of the adaptive settings. Hmmm...I'll scour my Bentley manual tonight to see if they have anything to say about this issue.

FWIW,

Theo

 

Yeah, I'd love to try it out myself too!

Anyway, I'll see what I can learn from folks at dealership---I'm going over there in the next few days to try out an '05!

 

Thanks again Koopah! (I missed your post when I last posted in reply to Lot15.) I like your explanation. Let us know if you learn anything more about the details of the software "logic". I love this car!

 

I've taken the liberty of cutting and pasting Andy Ross' post in the "Rich vs Lean" thread as it is relevant to this one:

Andy wrote:

"Here's an explanation of fuel trim I wrote a while back:

There are several different learned adaptations that take place, but the most significant and noticeable is fuel trim. Here is an explanation of fuel trim and what it does for us.

The DME controls Air/Fuel mixture in order to maintain power, efficiency, and emissions. A/F is expressed as either a ratio (14.7:1 for example) or as a Lambda value. With iso-octane ("ideal" gasoline), Lambda of 1.0 is equal to 14.7:1 A/F. This is known as "Stoichiometric", a condition where there is a perfect balance between oxygen molecules and the various hydrogen and carbon based molecules in petroleum. With the oxygenated gasoline that most of us use, actual A/F ratio of 15:1 is closer to stoichiometric.

If Lambda is greater than 1.0, then there is a surplus of air and the engine is running lean. If Lambda is less than 1.0, then there is a surplus of fuel and the engine is running rich. It should be noted that the ratios are mass-based, not volume-based.

So, why don't we always run at 1.0 all the time? Well, we do MOST of the time. At cruise and idle, mixture is held tightly to 1.0 to keep the catalytic convertor at optimal efficiency, so the emissions are minimized. However, when we need acceleration, the mixture gets richer. Why? Maximum power is made between 0.85 to 0.95 Lambda (12.5 to 14.0 A/F with iso-octane). So, under acceleration, mixtures get richer. Sometimes you want to get even richer under acceleration to keep detonation (pre-ignition of the mixture from excess cylinder temperatures) away. The MCS engine, which has a relatively high compression ratio for a supercharged engine, which especially under lots of boost, is very succeptible to detonation).

So, now that we know that the ECU wants to be able to control the A/F ratio. It has a prescribed set of values (maps) for a given RPM, Load, etc. So, the DME tells the injectors to pulse for exactly XX.X milliseconds and that SHOULD get us the proper A/F ratio that we want. Well, if you tell an employee to go do something, you want to make sure they actually did it, right? The ECU has some snitches (the front O2 sensor and the MAF, for the most part) that will report back whether or not the desired mixture has been attained. The rear O2 sensor is used mostly to monitor the condition of the catalytic convertor, although in some applications it also contributes to trim information.

Based on feedback from the snitches, the DME learns to apply a correction factor to its commands to the fuel injectors. If you know that your employees take longer than the standard allotted time to do a specified job, you will need to adjust for that in your planning (injectors are in a union, so it is tough to fire them). The learned values go between the maps in the ECU's Flash ROM (the "chip&quot and the signal to the fuel injectors. These learned compensations are known as "trim". So, when you see "trim", it means "compensation".

"Add" means additive trim, which is addressing an imbalance at idle. When the ECU is using additive trim, it is telling the injectors to stay open a fixed amount longer or shorter. The malfunction (e.g. vacuum leak) becomes less significant as RPM increase. For additive adaptation values, the injection timing is changed by a fixed amount. This value is not dependent on the basic injection timing.

"Mult" mean multiplicative trim, which is addressing an imbalance at all engine speeds. The malfunction (e.g. clogged injector) becomes more severe at increased RPM. For multiplicative adaptation values, there is a percentage change in injection timing. This change is dependent on the basic injection timing." - andy@ross-tech.com

Wonderful explanation. Thanks, Andy!

 

Very helpful information, thanks everyone!

 

OK! Superior explanation from a guy who knows more about DME's than MINI (Seimens) obviously does!

Thanks ofioliti and Andy!

Theo

 

Did an experiment: IN the past few weeks I have changed my driving habits by keeping revs high, shifting at >4500 rpm, "cruising" on the highway in 5th gear instead of 6th, etc. (as the car "should" be driven). I now find that the car does respond differently! I am now consistently chirping the tyres as I take off from a standstill! My right foot isn't any heavier than before, but the car seems to be giving more ooomph upon launch. Even my SO has noticed it ("Was that us? It didn't do that before???")