Flex Fuel and Lean Cruise Patches for OS 12587603
Posted: Sat Mar 05, 2022 2:10 am
Edit 06/27/22: Added "EQ Spark Advance Multiplier Vs. MAP" to the XDF. This table multiples the added spark when in Lean Cruise and was set too low to make a difference. The patch will change all values to 1.00 so that the timing added in "B5908 - EQ Ratio Spark Advance Correction Vs. EQ Ratio Vs. RPM (Lean Cruise) (12626)" will be a 1:1 ratio. So if one puts 10 degrees in the box, the PCM will add 10 degrees to the base timing regardless of MAP value.
Edit 05/05/22: Fixed the layout of table B7004 (Major order by column) and changed the address in one of the patch items as it was incorrect (0xB7AE, previously left this parameter as 0).
Edit 04/10/22: I'm surprised nobody brought this up, but I had B3634 defined wrong. It's supposed to be 4 bytes long, not 2 as I had it in the previous version. This oversight essentially would cause you to have to wait up to millions of seconds for lean cruise to kick in. I've made the correction to the parameter and the patch. If you have previously downloaded and try the XDF, but were not seeing results, please use the re-defined parameter in the below XDF to change the value to something more reasonable.
Edit 03/14/22: Changed the description for B3639 - Lean Cruise Enleanment AFR and B3639 - Lean Cruise Enleanment Lambda. Now these tables are for reference/sanity check only, should not be edited as this would cause bogus values to show up. Only edit the B3639 - Lean Cruise Enleanment EQ Ratio table.
Also the addresses for the Lean Cruise parameters were offset and now are fixed, so if you have a version previous to Beta 2.4, please update.
Edit 03/07/22: Added two more Flex Fuel parameters to the patch, B3627 - Afterstart Enrichment Decay Delay vs. EXT and B3628 - Afterstart Enrichment Decay Step vs. ECT.
With gas prices going through the roof I thought that posting an XDF that could improve your fuel economy and fuel selection might be helpful. All of this information is already out there, I just compiled it in a single XDF and made two patches so that it would be easy to implement. Make sure you have a copy of your bin file before applying the patches as they cannot be removed, but the two functions can be turned off in the XDF later if so desired.
!!! DISCLAIMER !!!
I'M NOT RESPONSIBLE IF FLEX FUEL OR LEAN CRUISE BLOW UP OR MELT YOUR ENGINE. BE SMART, USE YOUR BRAIN AND ASK QUESTIONS IF YOU ARE NOT SURE ABOUT SOMETHING.
FLEX FUEL PATCH - Applying this patch will turn FF on and populate all the necessary parameters with values taken from a P59 2004 Flex Fuel Silverado L59. There are 30+ parameters that need to change for FF to work as the factory intended and they are automatically populated when applying the patch. Will additional tuning be required? Of course. The patch gives you a good starting point.
YOU WILL NEED TO INSTALL AND WIRE IN A GM FLEX FUEL SENSOR BEFORE APPLYING THIS PATCH!!! There are some notes in the patch parameter summary, but it is not by any means a complete write up.
LEAN CRUISE PATCH - Applying this patch will turn on Lean Cruise like in the Holden vehicles and populate all the necessary parameters with values taken from a 2004 5.7L Holden Commodore M6. There are 9 parameters that need to change for Lean Cruise to work and they are automatically populated when applying the patch. Again be smart, use a wideband and verify that the PCM is applying Lean Cruise correctly.
Make sure you do a full flash (Write Entire) of the bin file after applying the Lean Cruise patch.
If you see multiple tables for the same address those are duplicates with either different units on the rows and columns, different units in the parameter or the rows and columns are transposed to make it easier to copy and paste from other sources. No need to change them all, a change in one will be reflected in the others.
If you see any errors, please comment so that I can make any necessary changes.
Edit 05/05/22: Fixed the layout of table B7004 (Major order by column) and changed the address in one of the patch items as it was incorrect (0xB7AE, previously left this parameter as 0).
Edit 04/10/22: I'm surprised nobody brought this up, but I had B3634 defined wrong. It's supposed to be 4 bytes long, not 2 as I had it in the previous version. This oversight essentially would cause you to have to wait up to millions of seconds for lean cruise to kick in. I've made the correction to the parameter and the patch. If you have previously downloaded and try the XDF, but were not seeing results, please use the re-defined parameter in the below XDF to change the value to something more reasonable.
Edit 03/14/22: Changed the description for B3639 - Lean Cruise Enleanment AFR and B3639 - Lean Cruise Enleanment Lambda. Now these tables are for reference/sanity check only, should not be edited as this would cause bogus values to show up. Only edit the B3639 - Lean Cruise Enleanment EQ Ratio table.
Also the addresses for the Lean Cruise parameters were offset and now are fixed, so if you have a version previous to Beta 2.4, please update.
Edit 03/07/22: Added two more Flex Fuel parameters to the patch, B3627 - Afterstart Enrichment Decay Delay vs. EXT and B3628 - Afterstart Enrichment Decay Step vs. ECT.
With gas prices going through the roof I thought that posting an XDF that could improve your fuel economy and fuel selection might be helpful. All of this information is already out there, I just compiled it in a single XDF and made two patches so that it would be easy to implement. Make sure you have a copy of your bin file before applying the patches as they cannot be removed, but the two functions can be turned off in the XDF later if so desired.
!!! DISCLAIMER !!!
I'M NOT RESPONSIBLE IF FLEX FUEL OR LEAN CRUISE BLOW UP OR MELT YOUR ENGINE. BE SMART, USE YOUR BRAIN AND ASK QUESTIONS IF YOU ARE NOT SURE ABOUT SOMETHING.
FLEX FUEL PATCH - Applying this patch will turn FF on and populate all the necessary parameters with values taken from a P59 2004 Flex Fuel Silverado L59. There are 30+ parameters that need to change for FF to work as the factory intended and they are automatically populated when applying the patch. Will additional tuning be required? Of course. The patch gives you a good starting point.
YOU WILL NEED TO INSTALL AND WIRE IN A GM FLEX FUEL SENSOR BEFORE APPLYING THIS PATCH!!! There are some notes in the patch parameter summary, but it is not by any means a complete write up.
LEAN CRUISE PATCH - Applying this patch will turn on Lean Cruise like in the Holden vehicles and populate all the necessary parameters with values taken from a 2004 5.7L Holden Commodore M6. There are 9 parameters that need to change for Lean Cruise to work and they are automatically populated when applying the patch. Again be smart, use a wideband and verify that the PCM is applying Lean Cruise correctly.
Make sure you do a full flash (Write Entire) of the bin file after applying the Lean Cruise patch.
If you see multiple tables for the same address those are duplicates with either different units on the rows and columns, different units in the parameter or the rows and columns are transposed to make it easier to copy and paste from other sources. No need to change them all, a change in one will be reflected in the others.
If you see any errors, please comment so that I can make any necessary changes.