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2017 supercharged tundra 5.7 ffv 38 % alcohol reading. Dealer says there is a tsb for this but they cannot reflash computer because of hp tune for supercharger. Anyone else with this problem?
 

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I don't know about a reflash, but they need to reset the alcohol reading to zero and let it go through the relearn process. Not sure why that would be different with the SC.

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2017 supercharged tundra 5.7 ffv 38 % alcohol reading. Dealer says there is a tsb for this but they cannot reflash computer because of hp tune for supercharger. Anyone else with this problem?
I would contact Magnussion and or HP. You should be able to re download the HP tune. Mine came with a thumb drive that I down loaded the tune on to. I keep in my truck incase a dealer screws it up.
 
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What @310z said. The FFV tundras were never supported by TRD and Toyota for the supercharger program. The only tune the dealer has for your tundra is for a standard, non SC FFV. Plus, the TRD SC program was discontinued by the 2017 model year, if memory serves. In short, the dealer can’t help you. HP tuners, magnusson, or the shop that installed the setup (who would most likely contact HP tuners) would be your best ticket. But, it wouldn’t hurt to disconnect the battery cables for 20 mins or so and see the computer will relearn the fuel parameters.
 

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Discussion Starter · #6 ·
I don't know about a reflash, but they need to reset the alcohol reading to zero and let it go through the relearn process. Not sure why that would be different with the SC.

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Tech reset it to zero.
I have submitted a ticket with hp tuners. Hopefully i will get a reply.
I would contact Magnussion and or HP. You should be able to re download the HP tune. Mine came with a thumb drive that I down loaded the tune on to. I keep in my truck incase a dealer screws it up.
I have the thumb drive.
Truck has had supercharger for almost 8k miles no problem until a week ago
 

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I assume you were able to confirm that it's at zero? They told me that it was reset and I checked via Bluetooth OBDII and it was not. Some of the techs don't know how to do it correctly. Another tech was able to actually reset it.

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There is an inherent issue if the truck is now reading zero%, unless you're running 0% eth fuel. Typically the truck will eventually lockout at 0%, even if you're running E10 after a reset, meaning the truck doesn't have any idea, and it has now locked itself out of reading. My 2017 did that, but oddly enough my 2010 never had a single issue.

I regularly read alc % on my 2010, and my 2017, noticed the 2010 was normally at 7-8%, but the 2017 was slowly climbing, then a reset, then slowly climbing to 28%, then another reset. Along with those rising numbers was dropping numbers in fuel economy, and a rough start issue sporadically. After fuel pump replacement the numbers have seemed to be steady again. I haven't read it in a while, but honestly I only drive the 2017 about 2000 miles a year now.


Back to my first statement, if the truck doesn't see 7-10%, when running 10%, it essentially isn't fueling properly to match what the truck thinks it's running. 0% is just that, 0%, 7-10% is what most pumps put out on average through my testing of fuels. Max of 10% is typically 8% on average. That means if it thinks 0%, but running 10%, well, that's just not right. I could go on and do the math as far as btu difference in e85 vs 10%, vs 0%, but it wouldn't change anything.

I can say since the fuel pump swap/tsb, I gained 2-3ish mpg once the ecu started reading correctly vs when it was locked at 0%. It isn't much of a gain, but going from 10.8 in summer to 13.5 is a different long term. I only drive short distances, all stop and go, unless I am running a 500 mile rd trip north.
 

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After properly resetting mine. The % stayed at 0% for a few tanks, then it started creeping up. Was at 4/5 for a while, then 10 ish, into the teens and now is in the 20s. I haven't had rough start issues but I have kept an eye on it and had it reset twice. Mine is also a 2017.

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After properly resetting mine. The % stayed at 0% for a few tanks, then it started creeping up. Was at 4/5 for a while, then 10 ish, into the teens and now is in the 20s. I haven't had rough start issues but I have kept an eye on it and had it reset twice. Mine is also a 2017.

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Have you had the pump replaced under the .tsb? The pump itself internally reads fuel flow, and an oring can leak, causing it to think you are consuming more fuel then it should be. There is not actual alcohol density reading as far as what's in the tank, only flow readings which sets off the settings based on fuel usage parameters, not fuel trims, not actual fuel alcohol density readings. This is all supposedly information. I can not confirm, but can confirm there is no actual fuel alcohol density sensor anywhere in the system.

in the 15-20k or so before the pump was replaced, I had the same thing. Rough start wasn't often, but about 28% it would happen, typically a start and die, or a start and fail to idle properly till restarted.
 

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I haven't had it done. Last time I went in they said that there wasn't anything to be done since I wasn't having a hard start condition... And typically they have to get it to reproduce in order to believe you. Was yours having the hard start when you had the tsb done?

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I haven't had it done. Last time I went in they said that there wasn't anything to be done since I wasn't having a hard start condition... And typically they have to get it to reproduce in order to believe you. Was yours having the hard start when you had the tsb done?

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There's a known .tsb for it, you might have to state you have had hard starting at times, or if you're good with the service dept, tell them you're alcohol reading keeps climbing after the reset. Then when it gets high, you have a hard starting issue.

Sometimes you have to get creative to get the issue fixed. But tbh, there's a .tsb, and it affects all 17's that are flex. They get to bill labor, make some ching, they shouldn't have to, nor want to replicate it to fix it, as it's a known issue.
 

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Maybe I'll try again... Also the last time I checked they were having shortages on the fuel pumps so maybe that factored into the resistance them addressing it.

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I have A19SR 5-T RD offroad with a non flex 57 One gentleman mentioned the gas mileage Issue in the city being very low I experienced the same thing on my 19 and not Butch better run highway maybe 14 Issue in the city being very low I experienced the same thing on my 19 and not Butch better run highway maybe 14 Getting ready to install the magnets and super charger Comes with new injectors and plugs not sure if the fuel pump is replaced or not does anyone know in 19 if they updated the fuel pump for this issue
 
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