What If? $8D (1227727 ECM) for TBI

[dave w]

not 100% certain of how 8D works, but in A1 and it's successors and predecessors, there is the "fueling mode select" and "cylinder count" as seperate items.

cylinder count is simply a multiplier for RPM/airflow/etc calculations, it's the fueling mode select that's used for the DTC41 info.

Ok, I have loaded $A1 .xdf/.bin/.adx into TunerPro RT. I'm not going to have much time to modify the ARUT.bin I have loaded. I'm on a learning curve with $A1! My thinking is, I should be able to flash the ARUT.bin with the $18 change and capture a couple more O'scope videos and .xdl file. Any other changes I should do to the ARUT.bin before I flash a chip and do one last bench test?

I also wonder, is there a make / model / year I can program into my AutoXray 7000 to scan $A1 with after making the $18 change?

Thanks,
dave w

[RobertISaar]

if you have the "KK41MODE" value (found at 04F1, assuming it's not in the XDF) set to $18, then no, not really? it should be enough to test anyways.

what's with the sudden change to A1? the same value should work in 8D.

and ARUT is a 91 J-body (cavalier) with a 3.1, should be easy enough to find an application for.

[1project2many]

cylinder count is simply a multiplier for RPM/airflow/etc calculations, it's the fueling mode select that's used for the DTC41 info.

Nothing in the old hacs is listed as a fueling mode select or anything similar. However, when looking at the code for "cyl select" error in $8D same values are listed in comments as what you've listed for the fuel mode values. Years of confusion over a simple misnaming? It's not like it hasn't happened before.

Dave, check the value at $8293 in $8D. I suspect it's currently $00. Change it to $18 and try in the TBI memcal.

[dave w]

if you have the "KK41MODE" value (found at 04F1, assuming it's not in the XDF) set to $18, then no, not really? it should be enough to test anyways.

what's with the sudden change to A1? the same value should work in 8D.

and ARUT is a 91 J-body (cavalier) with a 3.1, should be easy enough to find an application for.

The switch to A1 is for two reason, one is to capture data that could be useful in the future, and I have not been able to figure out how to change $18 in 8D. I'll look at Hex address 04F1 and post back what I find.

Thanks for the help,
dave w

[dave w]

oneproject2many, I can't find hex address 8293 in $8D.
I can try setting the $8D Cylinder Number to 18 and see what happens?



RobertISarr, I think I have correctly found hex 04F1 in $8D which I think is set to value 0C?
I can try setting, what I think is 04F1 from 0C to 18 and see what happens?

dave w

[RobertISaar]

you're referencing 04F0(line starts with 0), 04F1 is next to it and is currently $18 already.

[dave w]

you're referencing 04F0(line starts with 0), 04F1 is next to it and is currently $18 already.

Thank you for clarifying the Hex reference!

dave w

[EagleMark]

Humans start counting at 1. Computers start counting at 0. So who's the human who made computers count wrong?

[dave w]

Humans start counting at 1. Computers start counting at 0. So who's the human who made computers count wrong?

That reminds me of a sign I saw once ... there are 10 kinds of people ... those who understand binary and those who don't.

dave w

[1project2many]

Sorry, Dave. Too many years working with this stuff and too little time to make complete posts caused confusion. The addresses in the $8D hac are the addresses at which the calibration and program reside in the ecm. They begin at $8000 but the hex editor addressing (unless you change it) begins at $0000. So in order to view or change $8293 from the hac you need to look at $0293 in the hex editor.


I grabbed a sample cal (AWFU) from the $8D reference thread. The value there is $00. I can change it with hex editor and attach but you'll probably want to try it with the cal you've been using.

That reminds me of a sign I saw once ... there are 10 kinds of people ... those who understand binary and those who don't.

I love that joke. I think it was six_shooter's sig in a forum I was on.

[dave w]

Sorry, Dave. Too many years working with this stuff and too little time to make complete posts caused confusion. The addresses in the $8D hac are the addresses at which the calibration and program reside in the ecm. They begin at $8000 but the hex editor addressing (unless you change it) begins at $0000. So in order to view or change $8293 from the hac you need to look at $0293 in the hex editor.


I grabbed a sample cal (AWFU) from the $8D reference thread. The value there is $00. I can change it with hex editor and attach but you'll probably want to try it with the cal you've been using.



I love that joke. I think it was six_shooter's sig in a forum I was on.

I'll try changing $0293 and post back what I find.

dave w

[dave w]

I'll try changing $0293 and post back what I find.

dave w

Here is the screen shot of what I've done to $0293.

dave w

[EagleMark]

That would be correct.

[Six_Shooter]

I love that joke. I think it was six_shooter's sig in a forum I was on.

Yeah, I think I used that on V6Z24.com for a while.

[dave w]

I've completed the bench testing, the wire harness and ECM have been delivered.

I have a some interesting video's using $A1 with a TBI Memcal and $A1 with a V6 Memcal.

The testing I was able to complete late this afternoon.
Test 1: TBI Memcal $8D Hex address 0293 = 18 resulted with Error Code 41.

Test 2: TBI Memcal $8D Hex address 0293 = 00 with Number of Cylinder = 18 resulted with Error Code 41.

Test 3: TBI Memcal $A1 Cylinder Number = 18 (TBI) resulted with Error Code 41.

Test 4: V6 Memcal (BCC ASHH) $A1 Cylinder Number = 18 (TBI) Did Not have ERROR Codes.

Note: $A1 .adx file did not show a data stream, most likely because of the wiring differences between a V8 TPI and V6 PFI?

At this moment, I'm not sure what a good path forward could / should be. I like a combination that does not set error code 41.

Thanks again for everyone's assistance!
dave w