Lean Cruise, the real story

[GMPX]

Like the old fill the tank with new fuel to reset the Octane scaler internet myth, there appears to be another one gaining popularity. That myth is that Lean Cruise actually functions on non Holden cars, both EFILive and HPTuners have explained that just setting the calibration variables like a Holden will not give Lean Cruise on a non Holden Platform.

For those that can read (or rewrite) assmebler code, here's the actual check in the PCM operating code to ensure Lean Cruise will not function unless the vehicle is a Holden.

EFILive does NOP encourage you to change this code :wink:

Cheers,
Ross

moveq #2,d1 ; #2 = Platform is Holden
cmp.b (byte_0_1E5C5).l,d1 ; Check against Platform type in cal
bne.s loc_0_29A96 ; If not the Holden then skip Lean Cruise
jsr sub_0_2F68E ; Jump to Lean Cruise Subroutine

loc_0_29A96:
jsr sub_0_38372 ; Jump to Knock control subroutine

[wait4me]

Exactly, Thanks ross for making it proven. No one beleives me... :)

[87gmc]

so even if a full flash from a holden bin to lets say a camaro pcm, im talking a full flash not just the cal

[87gmc]

moveq #2,d1 ; #2 = Platform is Holden
cmp.b (byte_0_1E5C5).l,d1 ; Check against Platform type in cal
bne.s loc_0_29A96 ; If not the Holden then skip Lean Cruise
jsr sub_0_2F68E ; Jump to Lean Cruise Subroutine

loc_0_29A96:
jsr sub_0_38372 ; Jump to Knock control subroutine

I'm an accountant not an engineer :lol:

[SS2win]

so you just put the holden id in the vin? lol

[GMPX]

It won't help.

The ONLY way around this is to modify that platform check routine, or change the platofrm type to Holden in the calibrations (we don't allow you to do that), that will cause other problems anyway.

The fact that GM went to the trouble of checking what platform type it is means that they were probably directed by those in power to do so.

Sorry,
Ross

[87gmc]

It won't help.

The ONLY way around this is to modify that platform check routine, or change the platofrm type to Holden in the calibrations (we don't allow you to do that), that will cause other problems anyway.

The fact that GM went to the trouble of checking what platform type it is means that they were probably directed by those in power to do so.

Sorry,
Ross

Ok back to B3647 for me :D

Hey Ross tomorrow ill check out what you told me to do in checking state 05 for the B3647 table

[SS2win]

ok so replace the jump with a nop.. lol I'm not a programmer...

[GMPX]

ok so replace the jump with a nop.. lol I'm not a programmer...

Yeah, that would work if YOU want to do that, we won't.

Cheers,
Ross

[TAQuickness]

any good books on assembler code you could/would reccomend?

[GMPX]

Don't know, I started this stuff back in the Commodore 64 days!!

Unfortunatley the two people in the LS1 'scene', myself and Chris at HPT are maybe the only ones who know how to do this?.
The process.....

1 - Skip the Lean Cruise Platform check (different spot on all O.S's).
2 - Recalculate the checksum
3 - Fill Lean cruise table

NOTE: On ETC vehicles if you get the checksum wrong your PCM is toasted, chip off to recover it.

OR

Upgrade to any V3 O.S and use the MAP vs RPM AFR table to command leaner.

Cheers,
Ross

[Brains]

FWIW, the US GTO's pass the platform check ;) I'm running lean cruise on my GTO, and it in fact works like a charm.

[87gmc]

FWIW, the US GTO's pass the platform check ;) I'm running lean cruise on my GTO, and it in fact works like a charm.


Time to buy a Goat :D

[Tordne]

Sounds like good justification to go plead your case to the wife :D :D

You should win based solely on the grounds of current petrol/fuel prices :!: :!:

[Brains]

Its not a huge increase, but according to the DIC fuel mileage increases about 2mpg give or take a few tenths depending on speed. But hey, every little bit counts.

[87gmc]

Its not a huge increase, but according to the DIC fuel mileage increases about 2mpg give or take a few tenths depending on speed. But hey, every little bit counts. with the new table introduced on the custome o.s. i have seen a 4 mpg increase :D

[kbracing96]

Its not a huge increase, but according to the DIC fuel mileage increases about 2mpg give or take a few tenths depending on speed. But hey, every little bit counts. with the new table introduced on the custome o.s. i have seen a 4 mpg increase :D
Are you talking about the command A/F table, or is there another way to setup lean cruse with it? What setting are you using? I just got EFILive Commercial and am still trying to familiarize my self with it. I've been reading and reading, trying to learn all about this stuff, but haven't jumped in and changed anything yet. But I have all the tools :lol: I just want to get my turbo running the best I can and get lean cruse setup for now. I'm going to setup a 3 bar tune for the turbo when I get home, but I have a 1200 mile drive to get there in about a week and and half, would be nice to get the lean cruse working by then :D .

[87gmc]

Its not a huge increase, but according to the DIC fuel mileage increases about 2mpg give or take a few tenths depending on speed. But hey, every little bit counts. with the new table introduced on the custome o.s. i have seen a 4 mpg increase :D
Are you talking about the command A/F table, or is there another way to setup lean cruse with it? What setting are you using? I just got EFILive Commercial and am still trying to familiarize my self with it. I've been reading and reading, trying to learn all about this stuff, but haven't jumped in and changed anything yet. But I have all the tools :lol: I just want to get my turbo running the best I can and get lean cruse setup for now. I'm going to setup a 3 bar tune for the turbo when I get home, but I have a 1200 mile drive to get there in about a week and and half, would be nice to get the lean cruse working by then :D .

B3647 is the table :D

[soundengineer]

moveq #2,d1 ; #2 = Platform is Holden
cmp.b (byte_0_1E5C5).l,d1 ; Check against Platform type in cal
bne.s loc_0_29A96 ; If not the Holden then skip Lean Cruise
jsr sub_0_2F68E ; Jump to Lean Cruise Subroutine

loc_0_29A96:
jsr sub_0_38372 ; Jump to Knock control subroutine

can you tell me all that stuff that I am looking for in a 2001 camaro/firebird

I understand what I'm loking at... I just need some "reference locations"

I do NOP understand What to do ;) just dont NOP where to do it

[87gmc]

moveq #2,d1 ; #2 = Platform is Holden
cmp.b (byte_0_1E5C5).l,d1 ; Check against Platform type in cal
bne.s loc_0_29A96 ; If not the Holden then skip Lean Cruise
jsr sub_0_2F68E ; Jump to Lean Cruise Subroutine

loc_0_29A96:
jsr sub_0_38372 ; Jump to Knock control subroutine

can you tell me all that stuff that I am looking for in a 2001 camaro/firebird

I understand what I'm loking at... I just need some "reference locations"

I do NOP understand What to do ;) just dont NOP where to do it

:D

[87gmc]

moveq #2,d1 ; #2 = Platform is Holden
cmp.b (byte_0_1E5C5).l,d1 ; Check against Platform type in cal
bne.s loc_0_29A96 ; If not the Holden then skip Lean Cruise
jsr sub_0_2F68E ; Jump to Lean Cruise Subroutine

loc_0_29A96:
jsr sub_0_38372 ; Jump to Knock control subroutine


how do we actually get a program to read this i do have ida pro so tell me how to get to this point. It for educational purposes ONLY!

[wait4me]

Did you do the analysis and go thru and press c to make it show the code?

What happens if the branch if not gets nopped? :)

[soundengineer]

moveq #2,d1 ; #2 = Platform is Holden
cmp.b (byte_0_1E5C5).l,d1 ; Check against Platform type in cal
bne.s loc_0_29A96 ; If not the Holden then skip Lean Cruise
jsr sub_0_2F68E ; Jump to Lean Cruise Subroutine

loc_0_29A96:
jsr sub_0_38372 ; Jump to Knock control subroutine


how do we actually get a program to read this i do have ida pro so tell me how to get to this point. It for educational purposes ONLY!

It only looks like this in 1 particular OS...
every OS has it in a different spot....and with different references...
I've completely decompiled it....looked thru it 1 line at a time..... and still cant find it...
LOL

theres even a verbose mode that makes it so its telling you what the commands mean in assembler talk.....


oh...and basically..you hihglight the entire file(start at the top..select begin here and drag the little yellow arrow over the file bar...then go down and manually highlight the rest...)
then hit the code button and tell it to analyze and convert to code

[GMPX]

I just want to have a final word on this subject and further discussions can be done over at LS1Tech if needs be.

Yes the check is in a different spot on every O.S.

EFILive will NOT be helping anyone do this, it has been requested from some people that we do, but what might happen is then HPTuners may be used to flash in a Lean Cruise enabled O.S.
HPTuners want nothing to do with Lean Cruise on US vehicles therefore EFILive will not provide the knowledge to HPTuners customers (or EFILive customers) on how to enable Lean Cruise on a non Holden platform.

Sorry guys, that's life!!.

Cheers,
Ross