Reset Flex Fuel Alcohol/Ethanol Percentage Level with Bidirectional Scan Tool

It’s been a couple of years, so I don’t remember. There are a couple of YouTube videos to tell if yours is counterfeit. It honestly worked out for the best, since I really like this TopDon 900 Lite so much more than the Launch 90 I had. It’s twice as fast and does so much more, especially being bi-directional.

 

1 more question...

When you reset the fuel alcohol learning, does that also reset fuel trims or is there another step to do that or do they just autoadjust on their own over time? My long term fuel trim is at -30 so thinking trim should be zeroed too maybe?

 

Here's the TSB.

https://static.nhtsa.gov/odi/tsbs/2019/MC-10170730-9999.pdf

Step 7 is to perform the learning value reset.

Step 8 is to confirm the fuel trim values are 0.

Step 9 is to perform the fuel density learning value reset.

The other posts have not mentioned resetting the fuel trim values to 0. It may be worthwhile to perform the fuel density learning value reset, and see what happens to fuel trims after a few miles.

 

I was having the same problems a couple of years ago with the hard starts. My Blue Driver app showed around -85% long fuel trim as well. I didn’t know about anyway to reset the values. What I did was to run the tank down low, then filled it with E85, ran about 3 tanks through it, then I ran it low again, this time I filled up with no ethanol. (I normally do not use E85) It seemed to shock the ecm back into reading much closer to where it should be. I’ve probably put 100,000 on since that time with no problems until recently, it started acting up again. This time I have the Launch scanner. I just now reset the trims. It started perfectly, which has not happened for several days. So I will see how things hold up. If you can’t get the scanner, this might be worth a try. I had good luck.

 

Guys,

Can’t you just download an unlocked version of techsteam on an old laptop? Worked great for me. Mine is stuck at 14.9% on my ‘13 sequoia but it doesn’t affect drivability. I think it’s interesting that it’s just below the limit that Toyota requires to apply the TSB but in reading it sounds like it doesn’t really fix the problem long term anyways. Eventually I’d like to supercharge this truck with a custom tune and this whole concern becomes moot.

 

So I don't know if it becomes moot. I had the DAP tune, which I know isn't "custom" but it's definitely more in depth than a Bully Dog (and it was done in person), and a prevous mechanic was looking at the ethanol numbers to see if he could alter them and he couldn't. He literally shot them up to 100, and the number didn't change. He was perplexed. Then again, he was only one guy and after I quit taking my truck to him, I've questioned whether or not he did some of the stuff he said he did (rear main seal, alternator). Anyway, something to ask a more knowledgeable person about.

 

So a custom tune will get rid of the flex fuel percentage issue altogether?

 

I don't know.

 

Interesting detail about the Launch tools. I got one from scamazon and did fix my truck but I had to return the tool. Didn't have any of the extra "free" accessories it was supposed to come with. Like a longer OBD cable which would have been nice to have had and was part of the reason I ordered that specific item.
Confirmed that what I had was not a counterfeit device but it also was not a model intended for sale in North America. That means no US-based support. As others mentioned, Launch does not sell on that site. An email address for someone in China was the only support. The way I looked at it, that tool is a tablet which means it's going to want to install updates regularly so I couldn't trust that it would still work 100% after the "1 year free updates" period ended. To use it in the first place I had to install updates on the device, then when I plugged it into the truck, it didn't work and eventually gave a popup that more updates were needed even though it had said I installed all the updates. Eventually it connected and worked but I didn't like using it. Getting to the right menu was sort of a trial and error approach.
It's possible the seller is a legit dealer as he claimed but I suspect maybe he leaves off the detail about legal dealer in what country. I'm not going to spend that much money on a tool that may or may not work after a year with no easy support to fix it.

edit: costs more but buying directly for the real Launch USA distributor to get a model intended for USA and having US-based support might not be a bad idea if you want this kind of tool.

 

Gotta link for the one you bought?

 

It's first result if search "launch x431 crp919e elite". $465.
Same one OP mentions in first post except this one says 2024 now instead of 2023 though a listing for 2023 still exists too.

Launchtechusa.com is the real authorized US distributor that i suggest using if you want a tool to keep. They have some x-431 models but not same as scamazon and will cost more. Or try other brands.

 

My understanding is you can set fuel demand parameters without ethanol variability. So irregardless of what the monitor says, the tune will ignore it. I won't be able to confirm this for a few years but this has to be the case if companies are able to make superchargers for the FFV versions of these trucks. The other option is a piggyback setup. This is way to costly to do on a stock truck though.

 

Thanks bud.

 

Following up here.

I purchased one of the Launch tools and did the reset today. When the fuel alcohol percentage is reset ("Fuel Density Learning Value Reset" in the scan tool), that also resets the fuel trims.

With Techstream, each is a separate step.

 

Subbing for future use as I have a 2014 FF Tundra with the Harrop SC. I will have to pay more attention to the Wideband and watch for lean readings. I have read about the alcohol % moving up, but I need to get my tuner to see what it is currently.

 

2014 CrewMax Limited 4x4 FF Tundra here and I have been dealing with this off and on for about 7 years. I first noticed hard starting in 2017, about 3 years after purchasing the truck. I have never put anything except 87 and on occasion 89, if the gas station didn't have 87 in the truck. I have never run E-85 in this truck. The first time I took it in, I was unaware of this specific issue but told them that it would hard start and they checked the battery etc. and said it all looked fine. I left and it happened on and off for about a year, so I took it back to the same dealership. This was pretty much the same experience as the first time. They said nothing looked wrong. About 6 months later and after doing research I discovered TSB 0058-13 on my own. I took it back in with the TSB info and they checked and found code P1604. They updated the ECM and cleared the code. I still continued to have issues and took it back in a few months later. At this time Toyota Corp got involved and agreed to cover repairs under warranty. They made sure the ECM was updated and ethanol percentage learned was reset since it was reading 85. They had the truck for 3 days and supposedly replaced some internal parts related to the ethanol sensor though I see no record of that. They pretty much seemed to blame me for "intermittently filling it with ethanol gas" or with gas that has a "higher ethanol content than advertised", or leaving the gas cap off or not clicking it. None of those are factual. And not to mention, isn't the truck supposed to be able to handle E-85. Anyhow.... whatever they did do lasted for 4 years. I had zero issues in that time until about 2 weeks ago. The issue returned. I took it back to the same dealership and asked that they check the ethanol percentage learned as well as for any codes. They said it all looked fine (I don't think they checked the alcohol percentage at all) and that I needed a new battery. OK sure, I got a new battery and left for a trip. It still happened on the trip and today I took it back in with TSB-0166-19 indicating that its even more widespread than before and Toyota had to increase the affected vehicles. They checked the ethanol percentage learned and it is reading 85. Now they are saying that I need a new fuel pump, hose and ECM calibrated again for over 3K since I'm at approx 139K miles and the truck is 10 years old. I declined and opened a case with Toyota as I truly feel that this is a defect in this truck that I have had to deal with for 7 years and it has never been fully resolved. I'm still waiting on the results of case. If they will not cover it, then I'll likely just get the scan tool and reset it myself now and when it happens again. If I knew then what I know now, I would have passed on this FF truck and looked for one that didn't have it! Though everything else about this truck is solid and its performed great except for this specific issue.

 

Regardless if Toyota covers or not, just get the scan tool and reset it yourself. You need one anyway for doing this in the future.

It is a Toyota design issue, but the many dealer service departments make the whole problem worse by their ignorance/incompetence/greed.

 

^^^
This is the solution to your gripe. It's now on us as FF owners to maintain our trucks. Hell, it's way easier then even changing out the air box filter and it also helps you diagnose other issues.

 

Like he said,
Scan tool was less expensive than a trip to the dealer. These trucks typically have very little that goes wrong with them (coming from Dodge Dakotas/Rams). Scour this Forum for problems and you will find very few.
I spent too much time trying to rectify this problem myself and should have just bought the scan tool in the first place.

 

I saw a graph and a lot of articles on "Phase Separation" that made me wonder what if......

I see the TSB about possible equipment failure and/or faulty readings. So this could be the only issue. Not sure but thought I would pass on this info and let you decide.

But I wonder if some small percentage of these vehicles actually have a very high percentage of ethanol in their tanks and the vehicle sensors are actually reading the high level properly? No sure if this is the issue because if it was even the nonFF trucks would have this issue. Or do they not have the same sensors/equipment as FF trucks to detect high ethanol levels?

Basically phase separation is:

Once water gets in the tank at the gas station and causes phase separation and you put it in your tank you start to accumulate water and ethanol in the bottom of your tank where the pick up is for the fuel pump. So if all this ethanol and water is in the bottom of your fuel tank it would be hard to start, run rough, etc. And it would give you a high ethanol reading on a scan tool. If you have phase separation in your tank then with adding 10% fuel in a 26 gallon tank you would have at least 2.6 gallons on ethanol and water in the bottom of your tank. But if you filled up at a gas station with tanks that have phase separation your got 100% ethanol and water during your fill up. So the percentage of ethanol and water would be way over 10%. It would be a compounding problem. Each fill up from a bad gas station would make it worse and worse.

Adding more fuel then only gas goes to the middle or top of the tank and the additional ethanol and water with each fill up goes to the bottom of the tank once "phase separation" occurs. If you add fuel from a gas station with phase separation in their tanks you only make the issue worse with each fill up.

Seems the only way to fix the problem would be to run the tank dry which is a great way to overheat/destroy your fuel pump. Or to drain the tank which is very expensive and labor intensive.

Seems like good choice is to add an additive that rebinds the ethanol/water/gas into one mixture. Once it is "rebound" you can run it out of the tank with normal driving. Sure there are plenty of additives to chose from. I added a picture of one with good info.

It must be a significant problem at gas stations. They are tons and I MEAN TONS of articles about it telling stations how to fix their tanks/pumps. Looks like a very very common issue at gas stations.

Luckily I only use nonethanol fuel. I have yet to have the problem. But I needed an excuse to buy a scan tool. So I have one now in case this happens to my FF truck.
I also only go to new and national chain gas stations. I quit stopping at mom and pop, stop and robs and old country store stations years ago too. Luckily there are new QT gas stations with cheap nonethanol fuel all over my state.


One of the attached photos shows a good idea. Take an empty gas can to the gas station you use. Put some gas in it and hold it so that the gas from the bottom of the gas can pours into a gas container. If it has phase separation there will be two distinct separated fluids in the container.

 

That's interesting information! I've often thought maybe when the issue gets "triggered", it can possibly be tied back to getting gas at a different location or on a trip where I wasn't filling up at my usual place.

 

Mine has always been triggered by cold weather. The engine gives it way more fuel on a cold start (think choke) and even more fuel when it’s miscalculated the ethanol % to the point it’s flooded.

 

Hey guys just found this thread. Can someone who has used this scanner tool tell me what it is that this scanner has that can do the reset? I’m shopping around trying to find something cheaper because frankly it’s out of my budget. I found one (Launch X431 CRP429C) that has A/F reset and is cheaper but not sure if that is what is being used to do the reset. Any input would be appreciated.

 

I have had my 2016 since new. I was the first at my dealership to have this issue. 4 times in to the dealership. First one worked for about 2 years. Then again about a year then again then the tank drop and fuel pump when the service bulletin came out. I just ordered this scanner and will be trying it. I did get techstream but never got it to work. My buddy’s 17 is doing it as well so hopefully I can help him too. We run ethanol free gas in our truck and that helps. Maybe 1-2 cranks in the winter. Compared to 3+ it used to be. I don’t think Toyota has an actual fix for it. It’s probably something silly like a bad o2 sensor or something. Since the content is read post burn. But I will try this and see thank you for your post!

 

I think that’s exactly the cause.

 

Recently reset my truck and it’s running great again. F the dealership they had my truck for 11 months and were to stupid to fix the issue.

 

I used the Xtool D7 to reset mine so they did add that to the latest firmware.

 

If it's been running rich a long time due to alcohol reading being off, maybe that might eventually clog cats and mess with o2 readings too.

 

It's not A/F you need to reset exactly. It's fuel alcohol % learning value reset. Easiest way to know is contact seller and ask if that model can do it.

 

This is a good idea.
I bought this ethanol percent test tube.
Ive tested my local station and it passed but it's nice to have another tool and it's cheap and doesn't take up much space.