Thursday, November 06, 2008 - 11:06 pm, by: Luke Streat(Streatracer)
So I have too much time to think and I was thinking about how resetting the ecu always seems to do good things. I was wondering if its possible to rewire the ecu to reset every time you turn off the car? Im clueless about electronics but Im assuming there is a constant power feed to the ecu so that it retains its memory? and also an ignition feed for when car is running? based on these assumptions could you disconnect the constant feed and crimp it to the ignition feed so the ecu resets every time you switch off? Would there be any obvious downside to this? any opinions would be welcome
Thursday, November 06, 2008 - 11:16 pm, by: Grant Rowan(Booster13psi)
The problem is that every time you reset the ECU it has to go through the relearning process. I find it best to do 3-4 hard starts up to about 80kmh. This will put the ECU into a more aggressive mode. To have to do this every time you want to drive the car would get old very quickly.
Thursday, November 06, 2008 - 11:27 pm, by: Luke Streat(Streatracer)
"Seriously officer I was just resetting my ecu" rofl. You do make a good point though. How about wiring in a switch? somewhere handy in the cabin. Realistically I know its not that hard just to pull the fuses but my mind wanders lol. Also you wouldn't have to always have to teach it to stay in "Go fast mode" you could just cruise and then one day if you wanna play or your at the drags just crank it over and go
Peter Nitschke Junk Filterer South Australia UZZ30 UZZ31
Friday, November 07, 2008 - 06:32 am, by: David Vaughan(Davidv)
It does not go faster immediately you reset it. That is a function of how hard you drive it after the reset, and thereafter it will continue to learn your true driving practices.
If you want to go faster, put your foot down harder and the car will respond regardless of its prior ECU state.
Its learned state is for your normal driving and if the ECU behaves like a granny, it is only reflecting your habits. You are probably suffering a placebo effect anyway -- you have been driving quietly, reset the ECU and drive faster then say to yourself, "Man, the car is going faster!". Surprise.
Under the circumstances, I see no advantage in resetting the ECU except on a newly-acquired car or under other special circumstances.
Friday, November 07, 2008 - 07:18 pm, by: Ben Kelly(Ace)
can anyone here confirm that the v8 ecu 'learns' in the same way as the tt appears to? i am a bit sceptical that ecu reset does anything at all on the v8.
Friday, November 07, 2008 - 08:33 pm, by: Steven Anderson(Cusscuss)
im not sure either ecu really learns that much, on full throttle almost all factory engines will be on open loop as they dont have a wide band oxygen sensor, then closed loop on the narrow band at lambda for cruise.
Saturday, November 08, 2008 - 07:08 am, by: David Vaughan(Davidv)
I believe that on the V8 it learns shift points - how long to hold and when to shift down. I very much doubt it learns anything about fuel or timing other than about the quality of petrol you are using.
Would the TT be any different?
Steven's point more technically explains why I said earlier that at WOT the car will go just as hard regardless of any prior "learning".
Saturday, November 08, 2008 - 08:32 am, by: Chris Lock(Sledge)
David Vaughan wrote on Friday, November 07, 2008 - 06:32 am:
You are probably suffering a placebo effect anyway -- you have been driving quietly, reset the ECU and drive faster then say to yourself, "Man, the car is going faster!". Surprise.
The same as when someone gets a new exhaust i think.. 'hrmm..i'm using more fuel'..nothing to do with the lead foot, so you can hear your exhaust more..
Peter Nitschke Junk Filterer South Australia UZZ30 UZZ31
Saturday, November 08, 2008 - 08:47 am, by: Peter Nitschke(Pen)
Before the last Adelaide dyno day, I did a reset with the engine warm, then drove to the dyno taking the opportunity to floor it from the traffic lights along the way. There was hardly any traffic, and I only went up to about 60kph with each squirt.
I could definitely feel it lose some sluggishness after the first few starts and the car then pulled 149.7rwkw on the dyno. My previous dyno result was 131.6rwkw and the only real change was spark plugs and leads.
Considering the car is fairly stock, ie. no headers, no ECU chip etc. I am personally convinced that the reset was a good thing.
Sunday, November 09, 2008 - 08:32 pm, by: Ben Kelly(Ace)
Yeah well im still a sceptic regardless. It looks like a cut and paste from a manual from toyota engineers about model x, and it states 'vehicles [if in existence presumably] may require a relearn procedure...' It doesnt actually state which model if any have this feature.
Monday, November 10, 2008 - 07:20 am, by: David Vaughan(Davidv)
The features described do not say anything contrary to my post #3990, although I suspect I may have been slightly misunderstood.
The fact the car remembers about 40 starts supports my view that there is no escape from grannyness if that is how you drive.
Unless you had a genuine problem in the first place, the process of resetting the ECU will have greater impact on how you feel about the car than will the ECU reset itself, and any gain from resetting the ECU will be dissipated as you return to normal driving. Further, even with the ECU in a granny state, a couple of fast starts will help the ECU re-learn without having to go through a lot of other tedious reconfiguration processes, as pointed out by Dave and Mike.
Peter Nitschke Junk Filterer South Australia UZZ30 UZZ31
Monday, November 10, 2008 - 10:55 am, by: Dave Rose(Sand_groper)
Ben if you look to the bottom of the photo you will see LEXUS SC 400 its from my w/shop disk. After a reset the gear change on my car is all over the place for 5ks. And for some reason the disk will not let me save and send...so i have to take a photo..ah
Monday, November 10, 2008 - 05:48 pm, by: Ben Kelly(Ace)
Sorry Dave i did see that, i was just wondering if the publishers of the workshop manual had actually confirmed the facts. I suppose i am only questioning cos id actually like to be proven wrong ie. how come i dont notice a bloody thing after a ecu reset?
Monday, November 10, 2008 - 06:24 pm, by: David Vaughan(Davidv)
Because you were already driving fast? If you formerly lived in grannyville then an ECU reset should definitely have an effect. I just think (with some repetition and re-phrasing for clarity)
If you normally drive hard, then it is superfluous.
If you normally drive gently, there will be an effect but it will disappear quickly, so why fool yourself?
If you normally drive gently and want to overtake, flooring it should have as much effect in a granny-style car as in one which has had its ECU reset. Accelerating other than hard may not do so well because the ECU will be more reluctant to kick down or hold the throttle.
Finally, any ECU reset is a PITA because of the audio, video and seat reprogramming you have to do in a V8. Primitive cars may not notice that problem
Wednesday, November 12, 2008 - 11:43 pm, by: Luke Streat(Streatracer)
Im not really worried about the ecu learning shift points etc, Im only concerned with the ecu resetting the timing to suit a higher octane fuel(eg using 98 after running 91) The ecu needs to be reset before it will reset timing correct? or am I completely wrong? For instance tonight I filled up with 98 and chucked in an octane booster then when I got to drags I reset ecu. Would this give me any more power?
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