Reflashable OEM ECU possible

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Reflashable OEM ECU possible

Postby Fourplay » Sun May 20, 2007 12:20 am

Hi. I recently noticed this:

http://www.mr2oc.co.uk/ForumsPro/viewtopic/t=66668.html

It's a modification to the stock ECU enabling it to be repeatedly reflashed.

If this guy's claims are correct then the stock ECU may have significant potential, regarding tuning and datalogging capability.

It seems this guy is becoming discouraged due to lack of interest which is unfortunate as I'm sure this would be of interest to many of us :)

Cheers.
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Postby cardude » Sun May 20, 2007 6:30 am

it would nice to be able to retune our stock ecus like dsm's and hondas etc.
they can just chip their ecu's and tune them even in real time.
any reason why we cant do that with ours.
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Postby SuperWhite92 » Sun May 20, 2007 5:19 pm

cardude wrote:any reason why we cant do that with ours.


The jettronic architecture in the alltrac ECU uses ROM Memory, which means it can't be rewritten.

You will have to alter the architecture using techtom, eprom, or something similar to replace the ROM with read/write memory chips, and then you can just tune it to the capacity of the stock ECU, which is a lot more complex than DSM/EVO/Subaru ECU's.
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Postby JMR_AW11 » Mon May 21, 2007 8:21 pm

SuperWhite92 wrote:
cardude wrote:any reason why we cant do that with ours.


The jettronic architecture in the alltrac ECU uses ROM Memory, which means it can't be rewritten.

You will have to alter the architecture using techtom, eprom, or something similar to replace the ROM with read/write memory chips, and then you can just tune it to the capacity of the stock ECU, which is a lot more complex than DSM/EVO/Subaru ECU's.


That's true.

My mod to the ECU adds a daughterboard that has MCU+ custom logic chip + flash memory on it. I load the memory with the stock factory code.

There is three times more memory capacity on my board compared to stock and also it exploits the factory datalogger bus fitted inside Denso ECUs so it is possible to access low level ECU data in real time just like the original ECU developers did.

The board allows reflashing of the entire ROM via a laptop.

I also added some extra RAM and this will allow real time tuning (but I have to write the SW for this feature first :) )

When I do it can be uploaded as just another ROM upgrade via email/laptop.
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Postby cardude » Tue May 22, 2007 12:19 am

So this could be used to tune your factory ecu for different injectors and such :shrug:
I didnt understand all that.
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Postby Simba » Tue May 22, 2007 2:20 am

So, this is effectively an unencrypted techtom board?

More info required.

Lots of fast, loud things.
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Postby Fourplay » Tue May 22, 2007 2:38 am

Hi JMR_AW11, nice to see you noticed this post :wink:

It's interesting what you are doing and have discovered.

One would expect more interest in this project considering it has the potential to be the most cost effective method of controlling fuel and ignition whilst retaining the factory ECU.

cardude wrote:So this could be used to tune your factory ecu for different injectors and such :shrug:
I didnt understand all that.


I think he answers that here:

"In theory it gives access to all ECU parameters as anything in the ECU code/maps could be rewritten.

In practice it all depends on how many maps I grant access to via the tuning GUI.

The 3SGTE ECU is littered with little correction maps and thresholds and if i granted access to all of them it would confuse people and may even put people off. eg there about a dozen coolant correction tables in the ECU.

But in addition the the main fuel and ignition maps I would also give access to the other regular maps like cranking maps and the main warmup maps. Also the rev limiter and speed limiter."

I would definitely beta test it on my own car but I think the 11800 miles between us could be a practicality issue :)
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Postby cardude » Tue May 22, 2007 3:13 am

to bad we dont have something like dsmlink or hondata. :doh:
would this be like those or would this be way more toned down.
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Postby cardude » Tue May 22, 2007 3:23 am

n/m i just read the link. this sounds awesome.
you ship me one ill test it for you. :P
my ecu wouldn't be quite the same as an mr2 though
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Dumb question.

Postby GMan » Fri May 25, 2007 9:48 pm

> JMR_AW11
> Newbie

A newbie ? :P
Seems U have been around ECU tuning for a Long time.

> Joined: 21 May 2007
> Posts: 2

I am glad you made it over to our side of the pond !

One question I have is does any of the stock Toyota
ECU limit boost in 1st and2nd gear ?

I have debated and discussed it with several owners,
and they seem to beleive it does. I can't figure out How the
ECU would ever know what gear the drive was in. :shrug:

Good luck on the project. I'll keep watching.
Best to follow the MR2 discussion Or is there a better list ? :D

Regards;
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Postby C-dubb » Sun May 27, 2007 6:16 pm

gimmie gimmie!
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Postby built2run » Wed May 30, 2007 6:58 pm

well if you can do all of this then i assume it means that one can have their desired fuel/ign. maps for their particular setup with room for upgrades/changes meanwhile the stock ECU still makes all the safety corrections it deems fit? i would buy that in a heartbeat! smogable 500hp?? ah, dreams
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Postby JMR_AW11 » Sat Jun 02, 2007 7:32 pm

An MR2 turbo owner kindly drove over today (Andy =luthor1 on www.imoc.co.uk) and we tried my modded ECU in his car and it worked great.

He had a jdm MR2 rev2 turbo (3SGTE with AFM) and we drove quite a few miles doing testing and the ECU ran as stock (I left the ECU code as stock)

We then changed the ECU rev limiter down to 3200rpm in the code and retested the ECU and it limited at 3200rpm.

So yes, it allows access to all Toyota's original mapping and various settings for things like TVIS and speed and rev limiters. Also boost cut maps etc.

So now I know it works as well on a real car as it does on my simulator jig I can begin to make a board suitable for mass manufacture.
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Postby evo » Sat Jun 02, 2007 7:43 pm

:D good work!
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Postby shadowlife25 » Sat Jun 02, 2007 7:50 pm

Keep posting here so we know what's happening with this. I'm for sure interested in seeing the end results of this.
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