Enable Highway Cruise on 1227747 ECM

There's been some interest in the Highway Lean Cruise for the 1227747 ECM so I figured I do a how to.

From the factory the 1227747 ECM had a highway lean cruise option but GM had to turn it off because it was not in line with EPA regulations at the time. I had read some archives at DIY-EFI about this subject and I don't know who or which group of EFI pioneers to give credit to.But way back when Robert Rauscher aka RBob 10/30/2000 wrote a DOS version to make the needed changes to a 7747 bin file, then rewrote the application file for windows. I had to make a few changes so it would work up to Windows 7 through Command Prompt. RBob gets all the credit for this. I am just writing up a how to use the program he wrote.

At the end of this thread I will include the Zip file with all that is needed in it. There is a Read Me First, Read Me HIWAY747 and a Read Me ESC Done file that you should read and has information on what these patches do. There is also a XDF with all parameters needed.

Note: Use at your own risk. I am not responsible if you melt your engine. Go slow when tuning!!!

That said when this patch is installed most settings are done on the conservative side except Highway Spark is untouched.

This patch piggy-backs onto the hi-way spark advance code that is already present in the '747 ECM. In order for hi-way SA to be enabled, the ESC test must have already been successfully completed. If the timer @ 0x025 is set to greater then zero, the ESC test is also required for hi-way fuel to be enabled.

I think the easiest way for people today is to first find the command prompt on your computer. Windows 7 go to Start, All Programs, Accessories then command prompt and click on it to see where you are. Usually users/your name. If you know DOS ship next few steps and make a folder anywhere you want.

http://www.gearhead-efi.com/Fuel-Inj...9&d=1322550208

Go to that folder. In this case it would be C:\ Users\EagleMark and make a folder called "HiWay" or whatever you want. Then type chdir HiWay and click enter. Poof your in that folder.

http://www.gearhead-efi.com/Fuel-Inj...0&d=1322551188


Download the Zip folder at bottom of this post, right click save target as and put it in that folder, then unzip it there.


Next copy your bin file from a 1227747 ECM and paste it in that folder, rename it to something simple like asdu.bin. Always save an origanal copy of your bin.

Here's what I used.
ASDU-$42-5.7L-Auto.bin was my origanal.
asdu.bin was the copy I used in the HiWay enable program.
ASDU-$42-5.7L-Auto-Hiway.bin was what I saved the file to.

You'll notice in command prompt the "0" in command prompt has a dot in center or a slash through it, this is a zero. If you typed "O" the letter it would not have a dot or slash through it.

Here is the command: s19_pat_ HIWAY747.s19 0xD000 file2bepatched.bin
Must be exact including underscores, spaces, zeros, small letter x capital D and the exact name of your bin file to replace file2bepatched.bin

Now you have everything you need in the same folder so type in the command in the picture below and hit enter.


http://www.gearhead-efi.com/Fuel-Inj...2&d=1322551193

That has made the changes needed to the bin file. Rename it to asdu-hiway.bin Open TunerPro and click on Tools, then Difference tool and find the original bin file and the one you changed and renamed asdu-hiway.bin or whatever in the compare box and hit OK. The Difference window will open, make sure you have the original in one side and the hiway in the other and click search. You should see 48 bytes difference.

http://www.gearhead-efi.com/Fuel-Inj...3&d=1322551195

Your bin is now highway cruise enabled.

Next open the modified bin in TunerPro and see the differences made, although some are there to begin with they are not enabled. You can see a couple differences made in this picture with the compare bin. One thing to notice is there was no Highway Spark added! This was probably done as a safety factor so people don't just do this without testing on a untuned, low fuel pressure, over timed or just plain bad running rig.

I know my Suburban is well maintained and the tune is spot on. So far I have added 3 degrees across the board on this table and have no knock. This was tested on flat land which runs into mountain passes and I can watch the MAP kpa go above what's listed and it will go closed loop for a bit until parameters are met and go back into Highway Cruise. No knock. I'd like to find an F body bin that had this feature enabled from the factory and see how much timing they add? Although I don't think my Suburbans weight and wind Resistance could handle as much as a Camaro...


http://www.gearhead-efi.com/Fuel-Inj...4&d=1322551200

This next patch sets the status bit as though the ESC test for knock has already been run. This allows PE SA and Hiway SA to occur without having the knock test run.

This patch also bypasses the temperature and time delay window for PE mode.

That's it for me tonight. Stay tuned and we will go over the next patch in this Zip folder. :rockon:

Onto the next ESC Done patch in the Zip package. Since we already know how to use the program and command prompt I'll leave pictures out. Procedure is the same just differant files.

Copy your bin into the folder and rename from the origanal.

At the command prompt: Enter the command: s19_pat_ ESC_DONE.S19 0xD000 file2bepatched.bin
Note: The last argument is the name of the file that you want to be patched. This utility patches THAT file.
Hit enter. Your done. Copy that bin, rename it and use TunerPro Differance Tool to see the changes in bin file. Open TunerPro and click on Tools, then Difference tool and find the original bin file and the one you changed and renamed asdu-hiway.bin or whatever in the compare box and hit OK. The Difference window will open, make sure you have the original in one side and the hiway in the other and click search. You should see 55 bytes difference.


Remember to always save a copy of your origanal bin. Here is the progression of how I named mine.

Here's what I used.
ASDU-$42-5.7L-Auto.bin was my origanal.
asdu.bin was the copy I used in the HiWay enable program.
ASDU-$42-5.7L-Auto-Hiway.bin was what I saved the file to after HiWay enable.
asduhw.bin was what I used to do the ESC Done patch.
ASDU-$42-5.7L-Auto-HiWay-ESC-Done.bin was the final version after running these 2 patches.

Quick questions, I noticed that after the highway patch the "Options - Test High Gear in Highway Mode Spark" is still not set in tuner pro. Is this something that needs to be added?

Also there is a SA - HiWay spark advance but is set to 0. If you've already maxed the SA while tuning, is there any point to adding spark?

And what does the ESC patch do?

The document states
"This patch sets the status bit as though the ESC test
for knock has already been run. This allows PE SA and
Hiway SA to occur without having the knock test run."

But doesn't that already occur? Not sure what advantage this gives us...

I am not sure what "Options - Test High Gear in Highway Mode Spark" is for? Mine is unchecked and HiWay Lean cruise works fine.

Setting HiWay mode spark adds timing when in HiWay Lean Cruise, leaner mixture burns slower so this can be an advantage. Maximum spark allowed is 41.84 and you should not be hitting that much unless your decelerating, high vacuum/low kpa reading. Look at your spark table. I've added in 2 degrees in the entire table HiWay Spark table and checked for lean misfire with wideband O2 sensor. Could add more and others have but I like to keep it well inside safe area.

The ESC test is done once every time engine is started after qualifiers are met and forces engine to knock. Untill this test is done, or turned off, you will not get added PE or HiWay spark.

the high gear test option will basically disable highway spark in anything less than 4th gear(assuming a 4 speed) based on the 4th gear switch status, if it's selected. obviously only used on automatics, and those that have gear indication switches at that. some 4T60s(FWD) have a gear switch for 2nd, 3rd and 4th gears, to let the ECM know what gear the transmission is actually in at all times.

in some masks, highway spark is REQUIRED to be active before higheay fuel can be enabled. i usually modify my vehicles so that if one is active, the other must be active as well. if one deactivates, the other must deactivate at the same time. essentially turning the highway spark stuff into highway fuel added spark, since highway spark can normally be active WITHOUT highway fuel.

I know this is kind of an old thread but I am trying this out on my 91 GMC Full size Jimmy. The standard bin is the ARJT and I have modified with the HW lean cruise and ESC as per the instructions on this thread. When I did a bin differences and even noted the which I though appeared similar to what was posted here. However; when I loaded the ECM I immediately got a rapid flashing Service Engine Soon light. I tried the load on several different 512 chips with the same result. The standard ARJT bin works fine. I would take any suggestions at this point. I have uploaded my modified bins as per these instructions for reference. I am just trying to apply the HW lean cruise to the standard ARJT bin at this point and data log at a later date for fine tuning.

Thanks in Advance,
Steve

down load the latest xdl for the 7747 then on the parimater tree it has patches an it takes the guess work out of appling the patch. I would also apply the bpw patch. the file is on this site. :innocent: you should read some of the threads about hlc patch so not to damage your vehicale.:mad1: