Imlow78
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I just gave $389 for the Hp tuner module and one credit to work with the stock ecu on my 05 z71. Hope that helps.
Shannon
how to disable flex fuel?
- Thread starter slowride
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Shannon
I don't think HP Tuners can update the GM calibrations. You might be able to adjust some things but you'd want to know what you're doing.
Imlow78
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I thought he was wanting to remove the flex fuel stuff to try and get it to run correctly. I thought I read where that tuner could. Sorry guys.
Shannon
Shannon
randeez
Full Access Member
i dont think an 05 has a virtual sensor, should still be the old style type sensor by the fuel tank, it is expensive but probably about the same price as a tune @$400 bux. if you want a tune anyway, then go that route and detele it. when they fail, its displays higher ethanol content i guess gm figured it would be better to run engine rich, than lean if it happens.
i dont see how a virtual sensor would "fail" all it does is assign an ethanol percentage to how far/fast the fuel trims change. you would have a leak after the maf sensor causing it to think the afr is rising(going lean) and needs more fuel to bring it back down to the commanded afr.
from rock auto it looks like this:
i dont see how a virtual sensor would "fail" all it does is assign an ethanol percentage to how far/fast the fuel trims change. you would have a leak after the maf sensor causing it to think the afr is rising(going lean) and needs more fuel to bring it back down to the commanded afr.
from rock auto it looks like this:
Scottydoggs
Full Access Member
i just double checked my tahoe tune, its a 05 lt, hit engine then fuel tab, then the flex fuel tab, then you'll see a button for flex fuel and a drop down, set it to disable. then go to engine diag and then the DTC tab and find the codes for the flex fuel and set them to no report. all the codes have their description listed so most anything thats says flex fuel, set to "no error reported".
first things first tho, read and save the tune, name it stock what ever your truck is. with a do not touch, cause you never want to edit the original so you can always go back to it, or compare it to a edited file.
once saved open it up again then make your changes and go to file and save as, name it flex deleted or what ever comes to mind, and flash that file to the truck. i make a desktop folder for each car i tune and save the stock and all edited files in that folder. make slife easy when your looking for your files.
you'll also want to pull the radio fuse from under the hood fuse box and uncheck the high speed writing box in the flash window. leave the drop down box set to write calibration. never do a full write, unless you have to in order for some os segment swap stuff that your hopefully never going to need to do.
being my tune is open. its codes p0177 through p0183 delete all of them. my truck is non flex so those codes are already set to no report on my file. so you for sure dont want them active.
and pretty sure you need two credits to unlock your trucks pcm. what mine cost me. i did buy all my credits some time ago, they may have changed the sales with the newest mpvi2.
you'll also need to set up an account on the hptuners web site/forum. you need to sync the interface up to the web site to turn it on and make it yours. the directions in the box are pretty simple to follow, all that info is in there for ya. happy tuning
TollKeeper
Full Access Member
Or if you can live without the truck for a short time, you could pull the ECM, send it to @limequat.. I know he does the GMT360, I cant see that it would be much more of a tune for the NBS/NNBS
Have heard really good things about him..
Have heard really good things about him..
Scottydoggs
Full Access Member
i would buy a hptuners and own it. it can be used on many cars. the scanner works on just about any car.
Independent shops can do the calibrations, too. Check around. Really, it would be best to have them read by a Tech 2, just to see what calibrations are in it.
Mudsport96
Full Access Member
And that is why i quit working at the dealership....
And if the Tech 2 owner is set up with TIS2000, the programming itself is free for the NBS. I did this with mine. If TIS2Web (online) is used then there is a fee to download the calibrations. Obviously there may be labor/time charges for whomever is doing the programming. For $375 you could have a Tech 2 of your own.
Well I found a guy locally who has an HP Tuners setup. Says he can disable/delete the flex fuel deal for like $200. I was reading some other posts about resetting the air/fuel mix to something like 14.1 for running on pump gas with up to 10% ethanol. May try to get him to set that as well unless Im wrong there. I would have tried recalibrating the computer relating to alcohol content setting just to try that if I could have gotten it done at a lower cost, however my real goal would be to just get rid of the whole flex fuel programming and the headache Ive had from it over the past year. Im about at the point of wanting to sell the truck and be done with it.
After you do the FF delete, and sell it, be sure to let the new owner know what's been changed.
This has been the most frustrating vehicle Ive dealt with, other than some odd stuff Ive had that you couldnt find parts for lol. And I really appreciate the information people have taken time to post. I really dont want to get rid of it, as clean as it is and the low miles it would be hard to replace from what I see for sale. I could have just reset the alcohol percent with the Tech II and sold it to somebody but Im not that kind of guy. Unless I find some other info, I guess Im gonna shell out the $200 and hopefully that will work.
Scottydoggs
Full Access Member
200 aint to bad really, it costs $100 to unlock the file, be nice if he actually tuned the truck some too. i mean a 100 bucks for like 4 mouse clicks seems steep, trans tune would be nice. as thats most of what you feel when your tuning a stock car or truck.
As an update, I got the flex fuel turned off last week with HP Tuners. Ive had time to drive around a bit and do a couple fill ups. So far the truck runs much better and no more check engine light on. Checking my scan tool after each fill up, the alcohol percentage has stayed at 0. I had the guy set the alcohol percent at 5% on the fuel screen when he was running the program but as I said its showing 0%. Also set the fuel/air mix at 12.125 under column 0.0 in the stoich AFR tab but my truck is showing 14.67. Dont know if those values were supposed to get "locked in" or what, but that is what I had read to set them at in some other posts on related topic. My fuel trims went from negatives to positives and thats something Im looking into and will probably put in another post. Again, thanks for all the replies offering help
Scottydoggs
Full Access Member
how far pos? 5 to 8 is pretty normal. if that stoich AFR you changed was in the flex fuel tab im sure its ok. but once you set it to disable nothing about it should matter, its like a on off switch. scan your commanded afr should be 14.6 idle and cruise, then the afr drops when you go wot and enter whats called pe mode, power enrichment, it adds more fuel. commanded should be some where in the 12's wot id think. only way to really know is to run a wide band. then you know exactly whats coming out the tail pipe.
OK heres some pics. If you look at the vehicle speed on the screen, one is at idle with the - numbers, one is normal cruising at about 55mph/1500 rpms, and one is accelerating from 55mph not wot but maybe 50% pedal. They are average representations from multiple drives which only varied one or two numbers, but most of the time driving normally the long term trims both banks are trying to stay right about +6
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Scottydoggs
Full Access Member
13's are a bit lean. maybe have that afr setting put back to the way it was. see if it makes a difference.
swathdiver
Full Access Member
As Randy mentioned earlier, this model has the sensor and they are about a hundred bucks for an aftermarket one. We're referring to a GMT800 Tahoe with the L59, VIN "Z" Flex Fuel motor. Nothing man makes lasts forever.
