How does the B3646 in the lean cruise work?

[chevyguy7802]

How does it work and affect the lean cruise? Im kinda stumped, I have the lean cruise set-up and working great but im wanting to know how this works?

Thanks in advance!

[schwoch1]

From what I have read on the forums, lean cruise does not work unless you have a Holden car, and cannot be made to work on non Holden vehicles, something about in the code of the ECM it checks to see if it is a Holden, if it ain't, lean cruise no worky!!!

You can kinda make your own lean cruise by using one of the custom operating systems and leaning out the areas that are used at cruise and see what happens!!!

Hope this helps!!!

Mike

[Chevy366]

Mike , with some non-Holden tunes Lean Cruise can be enabled and works , look for section labeled CAX files .
Looks like maybe adds fuel if temps get to hot ?

[dfe1]

One of the software updates earlier this year (don't remember which one) makes it possible to enable Lean Cruise on non-Holden vehicles. After you make the Lean Cruise changes, you have to do a full reflash. I did my Silverado (didn't mess with cax files, just used the tables in the tune program) and it works as advertised. I haven't tried testing the effect of B3646, but my guess is that it's primarily designed to prevent the system from commanding an extremely lean AFR at higher coolant temps. Don't think you want to be cruising down the highway commanding 17.0:1 when coolant temps are 212+ (or 100+ for you guys who speak metric).

[smslyguy]

One of the software updates earlier this year (don't remember which one) makes it possible to enable Lean Cruise on non-Holden vehicles. After you make the Lean Cruise changes, you have to do a full reflash. I did my Silverado (didn't mess with cax files, just used the tables in the tune program) and it works as advertised. I haven't tried testing the effect of B3646, but my guess is that it's primarily designed to prevent the system from commanding an extremely lean AFR at higher coolant temps. Don't think you want to be cruising down the highway commanding 17.0:1 when coolant temps are 212+ (or 100+ for you guys who speak metric).

you wouldn't happen to have the software update available would you?? I am looking to run lean cruise on my 2000 gmc with a 01 o.s.

[dfe1]

I believe it's in the current publicly released version (Build 88). Go to
http://www.efilive.com/index.php?option=com_content&view=article&id=48&Itemid=124
and download the software. I'm almost positive that you have download all three programs so that everything is compatible. Let me know if you run into problems. I can probably get a file worked up that will have you lean cruising to your heart's content.

[rally1]

B3646 is a multiplier, if its set to 0 at a give temperature no change to the fuel mixture is made if its set to 1 it will command the fuel mixture multiplier from B3639, your best to set it up as 0 up to about 20-30deg before your normal running temp then you can blend to 1, that way it will only “activate” close to normal running temp.

[johnv]

Download a holden file 2001 to 2002 (not fly by wire) and you will be able to see how Holde have it set up :cheers:

[smslyguy]

i am running build 88 and i have yet to see lean cruise work????