Using the GM flex fuel sensor on an Fbody
The issue I was having turned out to be an issue in the calibration. I was using the 05 savanna base file and I had all the flex fuel functions and tables populated. I've been driving the car around on e85 with no issues, however in the VCM scanner, I could not get the "alcohol percent" to change from 0% or the commanded AFR to change.
Yesterday I decided to pony up 2 credits for an 05 Avalanche flex fuel tune to fix the logging issues. I used the new "segment swapper" feature and swapped over the 4l80e segment to the avalanche tune. Immediately when I started scanning, the "alcohol percent" read 33% and the commanded AFR adjusted accordingly as well. So, small win.
After trying the Avalanche file and playing with the segment swapper tool, I seen you can actually swap over the engine segment. Taking the base 05 Savanna file and the 05 flex fuel file, I swapped over the engine segment and this accomplished the same thing. I had full flex fuel capabilities including logging and this route does not cost any credits! Too bad I already wasted $100!
The 05 Avalanche is a DBW vehicle and I'm using DBC. This posed to not be an issue at all. The calibration has all the parameters for the iac and they are all populated so the motor ran just fine with the DBW tune. As long as the PCM is from a DBC vehicle it will operate a DBC engine regardless of the OS. This seems to be true for the P59 ecm's and I'm betting the P01 ecm's as well.
I still haven't played with flex fuel adder tables yet. Recently, I swapped my 3 bar brick style sensor for the ls9 map and my injectors for ID1000s. These changes are giving me some issues that I'm sorting out yet.
the LS9 map senor is working ok? you were able to use a negative number for the map sensor offset?
I have a 2005 2500hd with LQ4, ive been wanting to add the flexfuel sensor. my truck uses 12592618 OS, the flex fuel avalanche 5.3L also uses 12592618 OS. from what I understand from your post. I need to segment swap the engine segment into my PCM and then copy all my engine tables over the 5.3L tables?
If you happen across a situation where the VIN is incorrect for the PCM (some other software applications can write ANY vin to the PCM) you can license it with HP Tuners. HP Tuners will not allow you to create a mismatched VIN and will throw an error when you try to save it.
Example:
You have a "411" style (red / blue) PCM with a 1999 OS on it for a 1999 F-Body. You swap the PCM OS with a 2002 Tahoe flex OS because you want the flex tables. Same PCM, same car, new OS. HP Tuners will NOT allow you to write the 1999 VIN to the 2002 OS - even though it is the same physical PCM. They consider this invalid and the system stops you. You CAN write the OS to that PCM with a valid for 2002 VIN.
My situation:
I have a 1997 Thunderbird with a 5.3 or my 1961 Impala 6.0. I can't enter the Ford VIN or my 1961 Impala VIN (that isn't even 16 characters) in the GM PCM because HP Tuners sees those as invalid and won't allow me to create it. Again, I could read it and potentially license it as an individual (non group / blanket license).
Since reading / licensing and creating are two separate functions, you won't have to worry about reading or licensing it (with the current version of HP Tuners), only creation of what HP Tuners deems an invalid match. This isn't broken, it is how HP Tuners chose to structure their PCM recognition and licensing. Their competitor EFI Live uses a different method to lock the PCM's which is why they allow VIN overwrites to "non legal" for the PCM / operating system character combinations.
I hope this makes sense, I'm super tired and falling asleep at my keyboard right now. Haha
Last edited by gofastwclass; Apr 15, 2015 at 12:07 AM.
the LS9 map senor is working ok? you were able to use a negative number for the map sensor offset?
I have a 2005 2500hd with LQ4, ive been wanting to add the flexfuel sensor. my truck uses 12592618 OS, the flex fuel avalanche 5.3L also uses 12592618 OS. from what I understand from your post. I need to segment swap the engine segment into my PCM and then copy all my engine tables over the 5.3L tables?
2. I ended up using the entire flex fuel file but from what I remember, swapping the engine segment accomplished the same thing and if your original file is already licensed, swapping segments will not cost you.
I was wondering if anyone had gotten the GTO pcm working with flex fuel and a 2 or 3 bar map sensor. It seems that the road block on this is the COS have the option to enable flex fuel, but unless that OS was originally flex fuel then all the back ground tables aren't there to make it work properly....
I was wondering if anyone had gotten the GTO pcm working with flex fuel and a 2 or 3 bar map sensor. It seems that the road block on this is the COS have the option to enable flex fuel, but unless that OS was originally flex fuel then all the back ground tables aren't there to make it work properly....
There is a 2 and 3 bar MAP conversion for the 12579405 OS in HP Tuners, but I haven't tried them since the vehicle I worked on didn't need that or flex fuel.
There is a 2 and 3 bar MAP conversion for the 12579405 OS in HP Tuners, but I haven't tried them since the vehicle I worked on didn't need that or flex fuel.
Also i use efiLive so I'm not concerned with the vin part of it. I'm wondering if their COS will work doing it this way. My car is down right now, but in a few months i might give this a try.
Also i use efiLive so I'm not concerned with the vin part of it. I'm wondering if their COS will work doing it this way. My car is down right now, but in a few months i might give this a try.
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2. I ended up using the entire flex fuel file but from what I remember, swapping the engine segment accomplished the same thing and if your original file is already licensed, swapping segments will not cost you.
Also i use efiLive so I'm not concerned with the vin part of it. I'm wondering if their COS will work doing it this way. My car is down right now, but in a few months i might give this a try.
Hp Tuners on the other hand can support true flex-fuel capability for 99-02 with 2 bar+. But I'm not buying Hp tuners just to get that.
Hp Tuners on the other hand can support true flex-fuel capability for 99-02 with 2 bar+. But I'm not buying Hp tuners just to get that.
I thought the biggest thing was to have the base flex fuel file to have all the info and background tables for the COS?
So the people adding the flex fuel sensor to their f-body, I'm guessing they are not using custom operating systems????
I thought the biggest thing was to have the base flex fuel file to have all the info and background tables for the COS?
So the people adding the flex fuel sensor to their f-body, I'm guessing they are not using custom operating systems????
To answer your question, yes, they are not using COS tunes.
It would be possible to use a 2004 GTO flex fuel OS, however, that requires repinning of the PCM which is not something I want to do.
I don't know if there were any Flex Fuel silverados in 2002, but it may be worth looking into to see if there are any operating systems that match available COS's.
Additionally, the other option is to get someone with the ability to do hard code writing to segment swap the Flex fuel tahoe engine segment onto an 02 COS.

What are the code(s)? It's all a guess without them.






