 | Home > Puma (Tdci) > ECU self learning ? |
 
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| martinfiattech Member Since: 13 Nov 2013 Location: leicester Posts: 422  
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ECU self learning does not exactly learn your driving style, or cycle.
The ecu has parameters for sensor, actuator, injector, oil, dpf. Drift away from original manufactures specifications to allow for wear and tear old age, ect. On our multi air systems we have to carry out a cambelt relearn on fitting a new cambelt just to keep everything happy. So with self learning the ecu can use it`s own built in adaption map, as to whether a component is good bad or indifferent. Also to bare in mind a lot of components can and do give a calculated value to the ecu most air mass meters send a calculated signal / value which the ecu acts apon so the ecu is working on a pre calculated value from said sensor. So if said sensor is faulty the ecu works on a preset value or its own map by looking at other sensors and making up its own mind as to what said faulty sensor should be displaying / sending . thus keeping the vehicle up time extended and keeping the vehicle away from the dealer longer. So some times the data list you see on your diagnostic computer may not be the truth, as the ecu can and will alter the given / displayed value, we call this an adaption slope. One must be careful when working on said systems, it`s all well good replacing sensors clearing codes. But if you go in and start relearning given values the controller that was once happy with a given value from a component is now given a new value which maybe outside of specifications straight away and now you have a new fault which you have accidently created. On the other hand some times with vehicles that have faults and I can think of one ducato van I had, excessive black smoke, no power, poor mpg. Pluged in examiner code read, mass air flow adaption out of limits. While the computer was doing its thing I was going thru the service book and yes 35,000 miles over due service, poped out air filter blacker than the ace of spades. Well one new air filter clear codes, but mass air flow would not clear. Hmm I could see the given value was what I expected to see 693 mg at idle speed, but the fault would not clear. In this case a relearn of given values reset the ecu cleared codes. I actualy had to lie to the ecu and tell it there was a new mass air flow meter fitted so it would reset it`s adaption slope this saved the customer from buying a new air mass meter on re checking the given value for the mass air flow it was the same 693 mg. Data is a good thing but is it true. This is very common with semi auto transmissions if the fluid pressure sensor goes down the ecu defaults to full system pressure setting then monitors hydraulic pump current draw, as the draw rises to max the ecu pulls the pump down to try and keep the system going ect. It will even show you a pressure reading of what you expect to see, crafty eh! The deeper you go into these things the more mislead you can get. You can buy all the scan tools and scopes, visit forums etc. But you must understand the basics of the system and NEVER forget the basics of fault finding. Excuse the spelling I`am better with spanners and wires. |
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21st Apr 2014 1:05pm |
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| Cupboard Member Since: 21 Mar 2014 Location: Suffolk Posts: 2971  
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Now that was an extremely interesting post.
Thanks  |
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21st Apr 2014 6:01pm |
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| ericvv Member Since: 02 Jun 2011 Location: Near the Jet d'Eau Posts: 5816  
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Martin, does that self learning only apply to the recent Puma 2.2 ECU, or also to the Puma 2.4 ECU already?
Eric You never actually own a Defender. You merely look after it for the next generation. http://youtu.be/yVRlSsJwD0o https://youtu.be/vmPr3oTHndg https://www.youtube.com/watch?v=_GtzTT9Pdl0 https://www.youtube.com/watch?v=ABqKPz28e6A https://www.youtube.com/watch?v=rLZ49Jce_n0 https://www.youtube.com/watch?v=XvAsz_ilQYU https://www.youtube.com/watch?v=K8tMHiX9lSw https://m.youtube.com/watch?v=dxwjPuHIV7I https://vimeo.com/201482507 https://www.youtube.com/watch?v=ZSixqL0iyHw |
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21st Apr 2014 6:10pm |
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| munch90 Member Since: 26 Oct 2013 Location: guildford Posts: 3558
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they not so much self learning as driver reactive , if you drive steady they act steady , but give them a bit of stick they become bit more responsive , if that makes sense
bit hard to explain really with the rover mems system they did sort of learn and that was called a jack count resetting could sort some idle problems and few other problems after changing things |
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21st Apr 2014 6:36pm |
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| martinfiattech Member Since: 13 Nov 2013 Location: leicester Posts: 422
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Self adaptive parameters within vehicle ecus or as the now like to call them NODES thanks to can and multplexed systems, have been around for easily 15 years that I `ve seen.
Since the launch of bosch motronic 1,5 on Vauxhall vehicles I`am sure they had a adaption slope for idle air control, air flow meter ect. mind you I was a trainee back then it was 1990 just when carbs were going out the window and cats were appearing. Common rail diesels in the last 15 to 20 years are doing the same thing, with tighter emissions regulations longer service intervals the customer demands more and expects more. Lets face it if some one told you 20 years ago the police would be driving round in high powered diesel skodas you would laugh your head off. Adaptive parameters give the nodes of the vehicle a larger window of error along with the move to digital data transmission over analog data means the vehicle can carry on running with a poor signal from a sensor. Where once all data went along a serial line via a sine wave the node needed to see that waveform in its entireity to understand it. With digital data and a square wave or duty cycle waveform the node can see the signal and check it against its maps the amplitude of the signal is now less important so as long as it sees something it will work with it or do its best to work around it . I`am sure there are computer folk who can explain this better than me So that's about it my self I pefere the bosch edc systems over the ford Visteon systems we have in our landrovers. Oh well I would have liked the Iveco 2.3 multijet engine to, its much better Excuse the spelling I`am better with spanners and wires. |
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21st Apr 2014 7:55pm |
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