Reading 85% ethanol

2013 had been having starting issues. Checked with scanner and it is reading 85% ethanol. Been using regular 87. (10% ethanol)

called to talk to the dealer about bringing it in and didn’t get a lot of confidence that they were familiar with the issue.

Looks like there are a couple tsb’s regarding issue, and one requiring fuel pump replacement. Just looking for any feedback on anyone that’s had this fixed and of the reflash will fix or if I will need fuel pump also

 

Would like to know the same thing. Mine has been experiencing hard starts and I’m wondering if this could be the issue.

 

Going to take mine in next week I guess. Still having issue. They Dealer seemed a little clueless on the whole issue. I asked them if they could look into the tsb -# and they said they can’t. Wouldn’t tell me if fuel pump was available either until after a diagnostic for $130

i know for sure it’s needs the density re-learn bc I am constantly reading 85% ethanol

 

I have had mine flashed twice now. Truck is still starting rough. Part is backordered to replace pump. Should be here on Jan 30th. Cost is around $1300 for me with no warranty.

 

Why would you have to pay when Toyota has officially released a recall?

 

I feel like that’s what mine will need also. I mentioned to dealer that some parts were backordered and if they could look up tsb and check and they said they couldn’t look up tSB’s and I would just have to bring it in

If I have to replace fuel pump I might look closer at upgrading to larger tank

 

You guys having issues, who fuels with the vehicle running?

I have read that refueling with the engine running causes ethanol reading issues. Aside from the already known SW glitch. Just tossing out ideas. @KevinK

 

My 2¢... Get to your dealer. If it's fuel pump related you'll get a place in line with everyone else waiting for pump replacement as per recall. Free rental car as well. If you can swing it get the 46g TransferFlo tank.
https://www.tundras.com/threads/the-dreaded-trifecta-of-error-codes-fuel-pump-related.60285/

 

I can take it up with Toyota, but I think they have been fair in the past. They picked up the tab on the cam tower leak. I’m at almost 130k miles. I’m looking at this as a wear item.

 

I didn’t think the recall was for the 2013. Do you know what years it covers?

 

Don't know what years are covered. Mine was replaced last February due to hard starting issues. The issues have persisted and now I'm part of the recall according to my dealer. Bad pump I figure.

 

I think the most recent pump recall is MY18/19.

 

is it being implied that the fuel pump is related to the incorrect E% reading? unless Toyota changed how they read the E%, it's not done by the pump, but rather as a calculation based on the O2 sensors and stuff (which is a horrible idea, hence all the problems they've had).
Any TSB number associated with the pump that I can lookup and affected years?

 

TSB is T-SB-0166-19

 

E85 is well known for hard cold starts. If the truck starts fine on regular fuel but struggles cold on e85, you’re fine.

 

It's not so much the hard start itself (which does happen on regular fuel), it's the ECU incorrectly showing a fuel analyses of 85% ethanol in gas that is not E85.

 

Do they sell E85 at the station you fill up at? Not unheard of for drivers to fill the wrong tank. Read recently about one that put diesel in the gasoline tank.

 

I am not using e85. However the sensor and computer are reading e85.

using regular pump gas 10% ethanol

 

That's a feasible issue, but I've reset the alcohol density about 10 times, filled at different stations across the country and get the same result.

Oddly, now it reads 0% alcohol, which is equally wrong, as all the gas around here is 5-10%.

 

I am a little skeptical that a new fuel pump will solve the issue too. I do fuel with truck running.

 

Not sure how I missed this flex fuel being such an issue before I bought the tundra.
I think every tundra I looked at had the flex fuel option though.

I don’t won’t to pay to have density reset if it’s just going to keep happening

 

This is an old thread, but I'm having this issue on my 2016 Tundra Flex Fuel 5.7. Hard starting and computer constantly reads 85% alcohol even though I've never filled up with E85. Fuel type reads "Ethanol". I reset the percentage to 0% and it came back to 85% shortly after... Anyone else? I'm at 143K miles and this came out of nowhere.

 

I have not heard of any fix even the individuals that mentioned while having the new fuel pump replaced and after installed along with the software updates newer calibration was performed they state that it’s returned with the same situation reoccurring.

I’m currently running e85 as of today I have not had or experience any issues period while it was stock and even running on a tune.
Yes I get worse fuel milage on e85... but if its just normal driving around town and cruising I get 1-4mpg difference with pumpgas bs e85... when I am in it to win it I could care less about fuel lol.
First off in the tank ( where the fuel pump is) there is a sensor that can detect E85 fuel... Once the sensor has said (yep e85) a signal is sent to the ECM. That point the ECM goes to a different fuel/ignition CURVE.. When the sensor doesnt see E85 the ecm runs in normal mode.. You can switch back and forth if you want from e85 to normal 87 or 93 ron fuel you normally use. Only difference is really in timing and injector pulses thats it.

 

It's sensorless which is why it can be a bit wonky. It just sees how long it has to run the injectors to keep stoich readings on the a/f sensors. Problem is, the fuel trims and the ethanol offset are both factored in, and fuel trims are rpm-dependent and long term fuel trims alone can run at least 30% off without a check engine light (on my truck anyway). So you can have regular gas in the tank, a false 85% ethanol value (makes it +30% or so), followed by a -30% fuel trim and burn stoich. Truck runs fine in closed loop, potentially runs pig rich when it goes open loop at high rpm, and has trouble starting because there's likely no fuel trim calculated when the starter cranks.

I've had the opposite issue. I had e85 in the tank, a false mid twenties ethanol value, and long term fuel trims in the +25% range. It ran fine in closed loop and had no start problems, but at high rpm open loop it showed about .91 lambda on the a/f sensors which is pretty lean. On gas that lambda is usually down around .8 in those conditions. On the plus side, when I switched back to gas the ethanol reading has stayed on a hard zero ever since.

 

Calibration code always needed for the engine to confirm that the software is updated. The flex fuel can run E85, I believe it should read below 30% closer to 15-20%. If the software update has not been done then all of this is for nothing.

The calibration should happen on its own when vehicle fuel level changes more than 3 gallons, this reset is used when computer is recalibrated and fuel pump is replaced for extended crank or other various issues according to TSB that this reset procedure is take from. If you are using E85 it should read alcohol density of 85%

 

That is very interesting that it has stayed at 0 after using e85 and switching back to regular gas. I should run a tank of e85 to see what happens.

 

How did you reset the value to 0%?
I also have a 2016 5.7 FFV with 152K. My problems started in Feb. I had the fuel pump replaced and a re-flash per the TSB (that I paid for) around June. It was re-flashed a second time a month or two ago. Hard start again a couple of days ago. First time I'm using a reader to check alcohol content and I'm at 78%. I only use E10.

 

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