Reset Flex Fuel Alcohol/Ethanol Percentage Level with Dealer, Toyota Techstream software or a cheap Bidirectional OBD2 Scan Tool (Autel, Launch, Xtool etc)?
Here is the user working experience:
“I have a 2013 5.7 Flex Fuel Crewmax (67,500 miles). I searched for a solution and found the TSB to fix it. Went to the dealer to have them fix per the TSB, but they wanted $1200 and the fuel pump is on long back order. This past winter, I started having the hard starting problems due to the high alcohol percentage level issue (the motor incorrectly thinks I’m running E85 ethanol gas but I never have, which causes extended starter motor cranking, an overly rich stumble, and strong fuel smells when it does start). I also had reduced gas mileage overall.
I’ve also read that some Flex Fuel owners who have had the dealer fix per this TSB have had the same problem return down the road. I needed a solution now and read that resetting the Alcohol Fuel Density level to zero will be a temporary fix (and some report it’s a longer-term fix). It seems that some have purchased a Techstream cable with what appears to be unlicensed software and tried to reset their Alcohol level using that tool (some with success and others report many headaches/problems with getting that software to work properly – much posts about it). Not wanting to spend my precious time trying to get that Techstream software to work, and instead of purchasing a 2 day license from Toyota Techstream (the real version), I decided to find a reasonably priced (to me) bidirectional scan tool that would reset my truck’s Alcohol Fuel Density level.
Scan tool was less expensive than a trip to the dealer. I searched and searched, and the only tool I found that said it could do this that wasn’t big bucks was the Launch CRP919E (or many prefer the CRP919E BT Bluetooth version).
I purchased the Launch CRP919E obd2 scanner ($389 free shipping). Once I received the tool, proceeded to run the updates and that took around 30 minutes.
Took my scan tool out to my truck and started my truck and plugged the scan tool in. You need to do that to get the Special Functions updates you need for Toyota and then checked my Alcohol Fuel Density Level which read 85%. I was able to both read my alcohol percentage level (which was at 85%) and also reset that alcohol percentage level back to zero.
I have always had cheap scan tools, that could read codes and clear codes, but, for the money, this tool is very powerful. I will spend a great deal of time learning how to use the live data, and use all the special functions.
Seeing it was crazy high and the likely culprit for my problems, I then went into Diagnostic > Automatically Search >System Sclection > Selcet “ECMECT(Engine and ECT)” System > Special Functions > Fuel Density Learning Value Reset (that will reset your alcohol level to zero – it takes like 3 seconds). My truck now starts right up no problems whatsoever, I get better gas mileage, and it runs smoother (it’s noticeably better). I’ve rechecked my alcohol percentage level since that reset and it remains at zero for now.
When the fuel alcohol percentage is reset (“Fuel Density Learning Value Reset” in the scan tool), that also resets the fuel trims.
If I ever have the problem return (I realize it may), I’ll just pull out the scan tool and reset the alcohol level (it takes about 2 minutes once you figure out how to find the function in the tool). Anyway, wanted to let you know in case you ever have this problem and you want to get a tool to fix it yourself (and also have a scanner in your garage that can do many other things (e.g., for my wife’s BMW (reset this and that)).”
Autel and Xtool bi-directional scanners also reset alcohol fuel density.
Autel’s advanced scanners Ultra, MS909, MS908CV etc, go to Special Function->Fuel Density Learning Value Reset
Some users also used the XTOOL D7 and D8 etc scanners to reset alcohol levels on Tundra. They did add that to the latest firmware.
D7S also did it with no problem. Performed the “Fuel Density Learning Value Reset” using the D7S scan tool just now and truck started up great on cold start. Fuel trim values were reset also. The long term fuel trim was -23. After the reset it’s 0.
Hope this helps.