Adaptive memory what is it?

Smeegles · 06-09-2006, 08:15 PM

Hi again guys.
As I have posted My bike was playing funny buggers and they found fault in the TPS.
When they changed the TPS to a new one they purged the fault codes but they didn't purge the "adaptive memory" so the bike with the new TPS was still exhibiting the same problems.
After taking it back they disconnected the battery for a few minutes then reconnected it thus clearing the "adaptive memory"
forcing the bike to relearn all its settings.
My questions are:
How does purging the memory actually make the bike all of a sudden run well again? Is it because it is forced to get inputs from the sensors all over again?
Is it a good idea to disconnect the battery in future if one is to replace a faulty sensor?

What is the purpose of adaptive memory?

I've tried googling and came up with some results though I'm not happy with the explanation as I didn't understand it well and it refers mainly to cars.
(btw the bike is running better than it has ever run, crisp throttle response etc. but I'm still not confident till I have ridden it for a week or 2 and it doesn't exhibit these symptoms again.)

John Lyon · 06-09-2006, 08:19 PM

So because your bike "remembered" having a TPS problem, it made it recur?

Smeegles · 06-09-2006, 08:44 PM

Quote:

Originally posted by John Lyon
So because your bike "remembered" having a TPS problem, it made it recur?

That's what the theory is apparently if i would have continued riding it over a week then the new tps's setting would have eventually over ridden the old settings and the problem would have disappeared.
Now that the bike's memory is purged the problem hasn't recurred.
This is why I'm asking the question.
Exactly how does adaptive memory work and would it be wise to change a faulty sensor with the battery disconnected?
(The mechanic checked all the electircials etc before he did the memory purge to ensure there were no electrical or wiring issues and also checked all the fuel lines etc.)

ErricZ · 06-09-2006, 09:27 PM

Part of the zero=zero procedure is to disconnect the battery. When you re-connect after everything is buttoned up, you are supposed to turn on the bike, twist the throttle off-to-full a few times and then start it because the memory has been cleared and the TPS needs to be "re-indexed".

It works just like the adaptive auto trannies in a car, it's just RAM like in our PCs, not like a flash ROM or anything.

foobeemer · 06-10-2006, 03:57 AM

My wife has an adaptive memory. It works quite well at Lord and Taylor and Macy's but not so well around the house.

ninermatt · 06-10-2006, 04:09 AM

Quote:

Originally posted by foobeemer
My wife has an adaptive memory. It works quite well at Lord and Taylor and Macy's but not so well around the house.

My wife has selective memory, she only seems to remember the stupid things I do. I wish I could purge her memory with a couple twists of the throttle.

Peter Parts · 04:55 AM

Quote:

Originally posted by ErricZ
Part of the zero=zero procedure is to disconnect the battery. When you re-connect after everything is buttoned up, you are supposed to turn on the bike, twist the throttle off-to-full a few times and then start it because the memory has been cleared and the TPS needs to be "re-indexed".

ErricZ is right. But let me add:

The ECU memory is sustained with current from the battery even with the ignition key off. So to erase stored parameters, you must disconnect the battery or pull the ECU 15 amp fuse (which takes an hour less time, not counting time to find where you dropped the fuse).

On restoring power, the ECU must be again "taught" the anchor (or end-scale) voltages of the TPS. This is done by the two FULL twists procedure which prolly should be done slowly. I suspect that the ECU learns the anchor points over time (in the unlikely event you ever go WOT in your whole street riding lifetime on an S, eh) but this may take some time. I think this is an instance of "adaptive learning" and the ECU seems to have other parameters it learns through experience (possibly related to A/F choices) but I'm not certain if this or what if any things these are.

Neglect of the parameter purge and the two twist procedure is possibly a contributor to unexpected results (or initial funny results) with PCIII installations. Likewise for every TPS resetting.

The zero=zero (a critical setting that can easily and seriously screw-up a TB and the idle balance and all points of tracking between TBs... ax+b) is probably overused when just setting the TPS to .37 volts (a fairly non-critical, easily re-checked procedure) is sufficient. The factory-set idle stop - unlike the comparable carb idle stop - is not meant as an adjustment users should do at home... well, not without counting to 10 first.

I hope this helps answer your questions, Smeegles.

acidburn · 06-10-2006, 05:06 AM

so when i changed the battery two weeks ago, then installed the PC3 the next week and did nothing else am i o.k.?
Data point = Bike runs fine.

Smeegles · 06-10-2006, 05:36 AM

Thanks for the humorous and the technical responses folks.
It does clear things up.
cheers.

Moybin · 06-10-2006, 05:58 AM

Quote:

Originally posted by foobeemer
My wife has an adaptive memory. It works quite well at Lord and Taylor and Macy's but not so well around the house.

My dear old mom has a shuffling memory, with enhancements. She remembers sheet that never happened (at least to me). I wish I had had the childhood she remembers me having.