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Okay, I've had 4 re flashes on my truck to supposedly fix the issues with the troubled flexfuel program. None have worked, SURPRISE! When I call to find out how Toyota plans to fix this ongoing problem they tell me they have had no returns on trucks they have reflashed, except for mine. I personally find this hard to believe given the performance after about 4-5 refills. Rough starts, poor gas mileage, decrease in power and performance. So I ask you, my fellow flexfuel owners, has it worked for you?
 

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2011 flex fuel, 5.7L cm, 100k miles. Never been flashed, never had these issues.
 
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Had the reflash, no issues at all. Mileage actually got better. Don't know if that's an effect of the reflash or the truck optimizing to my driving habits.
 

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Had it. No issues before or after. As above mileage got a little better and shifts seemed firmer but that could have just been the adaptive thingy going on.

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Had the reflash done. No improvement. Still getting 7.2 mpg city. I've had the truck in 4 times to no avail.
 

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Mine was flashed and I didn't see a difference but min was flashed at about 2500 miles. No problems though. I drive fairly normal, getting in the throttle often, but making up for it by cruising on the hwy at 65 and 70. I avg about 14.5 but could get 15.5 if I never had any fun with it. On the 20's that came with the truck.
 

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Mine was flashed - no problems before or after. I actually think I get a bit better mpg after the flash - but I also installed a trd intake close thereafter so perhaps that's assisting with the .5-1 mpg improvement. 27k on the truck now. 2012.


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7.2 city? What about hwy? And what is your avg?

Maybe 10.5 hwy, 8mpg avg, but i really only drive locally. The problem is the ECM runs the engine in E85 mode and therefore pumps 40% more fuel than necessary. I suspect either the alcohol sensor or the fuel pump itself is defective. Toyota knows about the problem, but doesn't want to properly address the problem by replacing the hardware. They's rather issue ECU reflashes.

E85 has never been in my truck.

2013 FFV Tundra is crap. I really like the truck, just wish it was non Flex Fuel.
 

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Ooofff... That's awful. So you have informed the 800 number then I take it. You have kept all of your service documentation too, they don't record everything using the login provided on their website. And you have checked your states lemon laws, right? So after you have done that, you write a letter detailing your problem and give them 30 days to fix it. That's the process in Texas anyway. It does work, I've been thru it first hand. They will fix it or buy it back. Pm me if you want anymore details.
 

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Ooofff... That's awful. So you have informed the 800 number then I take it. You have kept all of your service documentation too, they don't record everything using the login provided on their website. And you have checked your states lemon laws, right? So after you have done that, you write a letter detailing your problem and give them 30 days to fix it. That's the process in Texas anyway. It does work, I've been thru it first hand. They will fix it or buy it back. Pm me if you want anymore details.
I appreciate the advice. I have initiated a case with Toyota Customer care and I've been building up the requisite dealer visits and service history. There are a number of members on this forum with similar problems stemming from the Tundra FFV system. I've been waiting for things to slow down at work so I can dedicate time to a full court press on this issue.
 
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Maybe 10.5 hwy, 8mpg avg, but i really only drive locally. The problem is the ECM runs the engine in E85 mode and therefore pumps 40% more fuel than necessary. I suspect either the alcohol sensor or the fuel pump itself is defective. Toyota knows about the problem, but doesn't want to properly address the problem by replacing the hardware. They's rather issue ECU reflashes.

E85 has never been in my truck.

2013 FFV Tundra is crap. I really like the truck, just wish it was non Flex Fuel.
Its not a part issue, the problem is with the technetium doing the reflash. Sounds like he never reset the alcohol density learning value after doing the reflash. I am willing to bet your alcohol density value is at 70% or more which is bad. The max it should be when using regular fuel is 15% any higher and you will have the issues your having. So if I were you Id go to the dealer and have them check the alcohol density value and show you the value before they reset it. This will prove the dealer is at fault and did not properly do the reflash as specified by Toyota.
 

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Its not a part issue, the problem is with the technetium doing the reflash. Sounds like he never reset the alcohol density learning value after doing the reflash. I am willing to bet your alcohol density value is at 70% or more which is bad. The max it should be when using regular fuel is 15% any higher and you will have the issues your having. So if I were you Id go to the dealer and have them check the alcohol density value and show you the value before they reset it. This will prove the dealer is at fault and did not properly do the reflash as specified by Toyota.
Thanks for info. This particular Toyota dealer/service department is definitely clueless. I made them reset the alcohol density value on my 4th visit. If was at ~86%. I can gaurantee it is already back over 50% after just a few tankfulls. I'll hook it up to Techstream myself sometime this week snd check it out. There are several members here for whom repeated reflashes did not solve the problem. A couple found relief after a new fuel pump was installed.
 

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Thanks for info. This particular Toyota dealer/service department is definitely clueless. I made them reset the alcohol density value on my 4th visit. If was at ~86%. I can gaurantee it is already back over 50% after just a few tankfulls. I'll hook it up to Techstream myself sometime this week snd check it out. There are several members here for whom repeated reflashes did not solve the problem. A couple found relief after a new fuel pump was installed.
Good Im glad you aware of the alcohol density value as 90% of people are clueless about it. It is possible the flex fuel sensor is bad, I have not replaced one yet so I cant really say thats a common fix but it may be a step in the right direction. And Im sorry to hear the dealer you go to is full of airheads.
 

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My 2013 DC TRD at 5000 miles was having the cold rough start problem and had it reflashed a month ago and so far no problems.
 

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I've been flashed, then deep flashed, and 2k miles later i'm back in the shop today. Rough starts. Runs ok (maybe not great, doesn't seem as responsive/powerful), and starts fine once is warm. I've updated the other thread too.
 

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sounds like some of you are well versed with this reflash. I bought my tundra as a certified used a little over a month ago. should I assume the reflash has been done? truck runs fine and starts fine, fuel mileage just seems low avg around 11 consistently. I know the wheels and tires are gong to knock it down a little but don't think it should be this low.
 

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there's more threads about this issue elsewhere on TT. I actually got a recall notice for the same type issue. had it reflashed once. wouldnt start, started hard, then finally went into limp mode one day. they reflashed and it seemed better. took the recall to the dealer and they reprogrammed the ECU (?) starts like a beast again. sounds like a pump running after i shut it down (was told it's blowing out the AIP) and mileage has dropped about 2mpg's :(
 

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According to the master tech at my dealer if you want to test your fix all you need to do is put more than 3 gallons of fuel in and within the first few miles push the accelerator past half way a few times. According to him this is what is screwing up the cpu and fuel rates. Once stuck there you will have to bring it back for a reset and reflash. It would be interesting to see if this is indeed what is causing the issue by having members without the issue try this.
 
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