Yes Tylor, you are the man. Mine is still running like a champ from your guidance.

 

Ima post this here too.

I've done the Flex Fuel sensor install using OS 12216125. After locating a 4l80e file that uses the same OS and performing a segment swap the trans would not downshift from third to first when coming to a stop. Hptuners support sent me a different file which solved the downshift problem but now the TC will not stay locked in 4th and when the shift selector is in D3 the TC will lock even thou in the tune it should not lock in third at all. It will constantly lock then unlock until I let off the gas to get below my targeted lockup speed. Before the OS change the trans worked perfectly so I'm ruling out mechanical issues. Does anybody have a GOOD WORKING 4l80e file with the above OS that they don't mind sharing? Any suggestions relating to the problem is also welcomed.

 

I believe Bigmandengo is running a 4l80e. We both used an Avalanche OS.

 

Is there a way for me to check the voltage output of the flex fuel sensor to verify it is good? I wired it up, changed the tune and the car is running super rich and barely runs. The hp tuners scanner is not showing an ethenol content reading. Changed back to my prevvious tune and the car runs fine.

Pin 56 is going to the white wire. Pink is going to ignition voltage. Black with white stripe is going to ground.

Edit:
After looking at the original post it seems that going by just the colors the harness has pins b and c switched which is the power and ground. I will try swapping them in the morning and seeing what that does for me.

 

The sensor itself should have words in the plastic that say GND VOUT VCC. on my sensor, the wire closest to the fuel line is 12v then GND in middle then signal furthest from fuel line.

 

I just noticed that...i think i had it correct the first time i wired it up. Either way its still not recognized by my scanner and the car barely runs.

 

You probably don't have a true flex fuel OS, if you did start with one in the beginning, you can lose flex fuel by doing some segment swaps. Pm me

 

Thanks for helping me out. I cant attach a tune in a PM so I will just post it here. I am using a p59 computer from a 2003 express. I have not upgraded to the newer express OS yet so all of the flex fuel tables are there except the open loop blend table. I havent done any segment swaps. Attached is the tune I am currently using. I am running speed density but not the custom OS speed density upgrade.

 

You can't turn on flex in the tune. It looks like you can, but it doesn't work. You must start with a oem flex fuel operating system file.

Edit: alternativly I think you can get it working by segment swapping from a known good flex fuel file. The problem is that the OS must match.

 

That explains it then....I will pull an 05 Express van tune from the repository and upgrade to that OS and go from there... Thanks!

 

you have a compatible OS. try and swap some segments from this oem flex file from the repo. this way you don't have to burn up credits.

 

Segment swap didnt help it still runs like crap...

Sensor is out putting 5.1 v...does this translate to 0% alchol content? What are the chances i have 100% gasoline in my tank? Im wondering if i could have fried my sensor messing around with the wiring.

 

Let me try to wrap my head around whats going on. You are using a 03 express PCM, not running the enhanced speed density option, and you are trying to just enable the FF ? Am I missing something?

What trans are you running? Are you going boosted? Check the wiring on the sensor not the wiring diagram.

 

Yes. Car runs fine I want the flex fuel option for forced induction. 4L80e. Ive checked the wiring 5 times now.

 

Im used a P59 PCM with a Avalanche OS. Reason was I had a hard time finding one that had the 3bar enhancement and flex fuel using the P59. I would suggest doing the speed density enhancement, do a write entire and see what it does. Also, you may wanna try setting the MAF to fail as well. Also, you have to check It sounds like you are getting some of the flex fuel to work but the scaling is off. My car shows the alcohol content super accurately. I can add non-ethanol fuel and it registers almost perfect. Now, the sensor does have a small delay in adjusting for the actual % . After a fill up, it usually takes a min or two to change the value. I can give you one of my tunes, but it really wont run your car, but you can at least compare whats different.

This is a Bigmandengo special. 98 Trans Am, P59 PCM, Avalanche OS, 3bar, 4L60E, FF

Like I said before, Tylor is the man. Super nice guy, serving in our Military and loves boosted LSX stuff.

 

I just loaded a known good flex fuel file and I still have the same issue. I am 100% without a doubt the wiring is correct. I think the sensor is bad.

 

Well, they are crazy cheap to try another one.

 

Can't see the original pictures of the install. Anyway to fix this?

 

nah photobucket is 100% fucked now

 

I managed to run my 2002 CETA with a 12216125 OS on the stock 411 PCM. But I'm having issues with the ABS light and fuel gauge. Would either of you guys running a 411 PCM with a 12216125 OS be willing to share your HPT file? I'd really appreciate it!

@bigmandengo

@Monte4ever
@landstuhltaylor