Lean Cruise, the real story

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August 18th, 2005
GMPX

Lean Cruise, the real story

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
August 18th, 2005
wait4me

Exactly, Thanks ross for making it proven. No one beleives me... :)
August 18th, 2005
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
August 18th, 2005
87gmc

Re: Lean Cruise, the real story

Quote:

Originally Posted by GMPX

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:
August 18th, 2005
SS2win

so you just put the holden id in the vin? lol
August 18th, 2005
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
August 18th, 2005
87gmc

Quote:

Originally Posted by 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

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
August 18th, 2005
SS2win

ok so replace the jump with a nop.. lol I'm not a programmer...
August 18th, 2005
GMPX

Quote:

Originally Posted by SS2win

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
September 9th, 2005
TAQuickness

any good books on assembler code you could/would reccomend?
September 10th, 2005
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
September 10th, 2005
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.
September 10th, 2005
87gmc

Quote:

Originally Posted by 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.

Time to buy a Goat :D
September 10th, 2005
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 :!: :!:
September 10th, 2005
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.
September 10th, 2005
87gmc

Quote:

Originally Posted by 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.

with the new table introduced on the custome o.s. i have seen a 4 mpg increase :D
September 11th, 2005
kbracing96

Quote:

Originally Posted by 87gmc

Quote:

Originally Posted by 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.

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 .
September 11th, 2005
87gmc

Quote:

Originally Posted by kbracing96

Quote:

Originally Posted by 87gmc

Quote:

Originally Posted by 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.

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
September 21st, 2005
soundengineer

Re: Lean Cruise, the real story

Quote:

Originally Posted by GMPX

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
September 22nd, 2005
87gmc

Re: Lean Cruise, the real story

Quote:

Originally Posted by soundengineer

Quote:

Originally Posted by GMPX

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
September 28th, 2005
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!
September 28th, 2005
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? :)
September 28th, 2005
soundengineer

Quote:

Originally Posted by 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!

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
September 28th, 2005
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

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