ECM Bus

[daveismissing]

I'm sure Bruce Plecan, Rob Rausch, Kent Chu and Bob Bailey have the architecture down pat but
has any documentation for the internal bus ever been released to the wild?

[dennisL]

The only internal bus for the ecm is for memory address (16 bits) and data (8 bits) lines.  I did a lot of research in the late 80s and most of the 90s on the processor and support chips.  During the same period I studied, no hacked all the chips I could get my hands on for the purpose of understanding the programming.  Eventually, I figured out all the prom data and code.  Later, I tackled the rom program.


I was more interested in the programming than the hardware so I didn't document much on that.  I still have my old notes though so I might be able to help you.  I did lots of documentation on the software, some of which Eric (TurboTweak) has on his website.  Over time, these docs were updated but not on the web site because nobody cares anymore about what goes on inside the ecm.


The processor is a Motorola 68HC11.  The Motorola user manual for it is 4 inches thick!  The processor chip started as a M6800 then was customized by GM.  The other chips used were also made for GM and don't have normal markings/numbers.


Let me know what you're looking for, I probably have it or can figure it out.  I've attached a memory map as a sample of what I have.

[dennisL]

You mentioned Kent Chu, well back in the day, he and I swapped emails when I was trying to get him to make improvements and fix minor bugs in Direct Scan.  When it became obvious that he had no desire to make changes, I offered to make the changes to his code and he could sell it as a new version.  He wasn't interested.  Oh well.


I taught Eric Marshal assembly language programming before he started TurboTweak.  I consider him a friend although he never did "pass the final exam" in my class.  Don't get me wrong, all the engineering ideas were his and he makes great chips.     Its only his programming techniques that I tease him about.


Dennis

[$1987 GN$]

You mentioned Kent Chu, well back in the day, he and I swapped emails when I was trying to get him to make improvements and fix minor bugs in Direct Scan.  When it became obvious that he had no desire to make changes, I offered to make the changes to his code and he could sell it as a new version.  He wasn't interested.  Oh well.


I taught Eric Marshal assembly language programming before he started TurboTweak.  I consider him a friend although he never did "pass the final exam" in my class.  Don't get me wrong, all the engineering ideas were his and he makes great chips.     Its only his programming techniques that I tease him about.


Dennis

I was getting that impression from a few of your posts.
Keep it up and hats off to you.

AJ___

[daveismissing]

It is sad that many guys put time and shared effort into research and somehow it ends up as proprietary product yet built on "open source" efforts.  The Lockers board was out there and disappeared. B&G seem to be the only makers of  megasquirt hardware.

I was interested in the bus pinouts. If Kent wasn't going to do anything further with his product he could have open sourced it.

And yes- we appreciate having your knowledge here.


 

[dennisL]

I was interested in the bus pinouts.

[/size]Are you referring to the ecm edge connector that PL (and DS) adapters plug onto?  If so, let me see what I do.  It might take a few days.

[daveismissing]

I was interested in the bus pinouts.

Are you referring to the ecm edge connector that PL (and DS) adapters plug onto?  If so, let me see what I do.  It might take a few days.

Yes, I would have expected that to be available by now. Not a rush, it will be something to engage my brain over the winter.
Thanks 


(Tho its already getting dark way too early   )

[daveismissing]

Adding to the list there was another dude who modified WinALDL to be Buick specific and that project was
abandoned when he got rid of the car. Another source lost. He was on mp3car.com as well.

[dennisL]

I have most of the ecm bus figured out but I'm having trouble locating some of the pin definitions for the processor.  From the little information I have, the processor appears to be a 6805.  I know the instruction set matches the MC6805 (little brother to the MC68HC11) but I don't have a pin diagram for a basic 6805.  I'll keep digging.


On another note, I taught myself Visual Basic a few years ago and in the process wrote a WINALDL replacement program.  After that I created a replacement/improvement to a program called TurboMeter.  Fun projects but since they were written in VB, the executables need VB support files to run.  Became too difficult to manage with all the Windows variations so I never released the programs.

[SuperSix]

Is the pinout the same as the 6800?
http://en.wikipedia.org/wiki/Motorola_6800

[daveismissing]

I have most of the ecm bus figured out but I'm having trouble locating some of the pin definitions for the processor.  From the little information I have, the processor appears to be a 6805.  I know the instruction set matches the MC6805 (little brother to the MC68HC11) but I don't have a pin diagram for a basic 6805.  I'll keep digging.

I have a guy.....

On another note, I taught myself Visual Basic a few years ago and in the process wrote a WINALDL replacement program.  After that I created a replacement/improvement to a program called TurboMeter.  Fun projects but since they were written in VB, the executables need VB support files to run.  Became too difficult to manage with all the Windows variations so I never released the programs.

Turbometer- that was it!


I kinda stalled around QB45... 


Can't compile VB into a standalone .exe or that requires the big bucks package?

[motorhead]

Not a rush, it will be something to engage my brain over the winter.

Since we won't have hockey to distract us...

[dennisL]

Is the pinout the same as the 6800?
http://en.wikipedia.org/wiki/Motorola_6800

I suspect its close but not exactly the same.  Not really sure. (?)

Can't compile VB into a standalone .exe or that requires the big bucks package?

[/size]That's right.  I happen to have the complete package for VB6 so that's what I used.  I don't want to spend the money for a current Microsoft Developers package.
[/size]
[/size]Both of my programs run if the appropriate support files are there.  And they're available, hell I'd even give out the source code if it would help someone, but who uses the 160 baud serial data these days?
[/size]What's that you say ... Steve probably does because he's "computer challenged".
[/size](Steve, I respect you but the other guys made me say that.)

[/size]Dennis

[I Love Factory ECMs]

Great Thread, Maybe someone here can explain my loss's I've had 3 different motor failures all due to trying to get a Stock type ECM to perform.  I am now also as of 9-14-12 banned from TurboBuick.com for 30days because of the same issue above i tried to express.LOL  What i was told by a person (Heavly into Engine Management)  in the 7's in the 1/4mile with Buick an company's still current an running, That there's a Factory Code in the all Stock ECM's that unchangeable an is design to make the motor go Lean on the Top End.  It's a Government/insurance/GM code   My 3 builds all had factory ECM's then a QuadAir mod. factory type, both Same effect. Eric burnt the chips, all different an specially designed for each the builds with translator plus it was professionally dynoed. (I'll save the place of the dynoing but there a "Buick Specialist" in Orlando,FL, easylie Googled) Dynoed at 610hp at the motor 533rwhp, ( i have 9" an full, larger exhuast)  Real World an Muiltipul Dyno Results where the car at just over 100mph fell over an leaned out.No Fuel issues!,Reds pump hotwired an voltboosted,inj. only at 50%,duty,it's on 93/Alky,22-23psi boost,No trans issue, All brand new billet job with artcarr3500,3:50 gear currie 9", an 28x10 et street tire.  It act's like the old speed/fuel pump cut off,But!!! It Lay's it over slower, It doesn't cut the pump an nose dive the car,It's a Fast gradual cutoff/lean out some how.  This is a video of the first motor loss, headgasket,1/8 mile mark,Ran 11.4 with 1.80 short,The Supra left on .006 light,When i hooked I smoked that Supra so hard he trapped 133mph to catch me! i hit the 100mph ECM fail like i felt on the street. This happen 2 more times,video's on my youtube channel,(watch me hang with mid 9 second prostreet mustang for 2 seconds till the 1/8...heh)  Buick GN vs Turbo Supra  I have a scantool log i tried to post here of first motor,It was to large the first time,If anyone would like it i can Email it,each file is 8mb,,I'll try an shirk it down later, It's 3 views of the same pass of a street 1/4 mile run,everything i thought was fine Then Zap, Motor's tunes Done...... Your going like bat-outa hell, then all of a sudden you can kick back an drink a cup of coffee.....  After a lawsuit ($30,000) i won from the "Specialist" for wasting 3 years me an my car's life i went to an XFI unit an the ECM fail Problem above Vanished!!!!!  2010 Buick Grandnational Dyno Runs!!!  I wish i had a dyno sheet, but my luck, Titain's computer was down that day,I didn't care, I had Cal Hartline tune it anyway, just 17psi boost. Notice, no over 100mph Cut off!! we Even made a mistake of leaving the parking brake on in the Car,on the last run, No Motor Damage!!!  Thanks, Bozo

[PacecarTA]

50% of a 50lb inj is 25lb hr x6lnj is 150 lb/hr which  will only support 300hp
your combo trapping what it did was closer to 500+hp
50% on your build that you listed
how is this an ecm issue ..its a tuning issue

for 500+ when i was on 50s and alky it took 86% inj duyt   at 25psi to go 10.90s (99 1/8 121 1/4)   on  a moderate motor build..  pte FMIC , stock shortblock , flat tappet 206 cam, home ported irons, stock intake , 3" maf pipe and lt1 3" /translator , stock headers ,3" thdp,    tt street 93 chip  oh and with a ta49

 to give you an idea of 50% of 50s
i ran 50s at 55% when i was pushing the stock turbo to 12.0s with a bone stock motor 22psi 110mph 1/4 , 89 1/8th