BATTERY CHANGE...

Recently had to change the battery in my '21 Tundra...

I contacted the service department where I purchased the truck and asked if disconnecting the battery would cause problems--They said "no"...(I heard it might)

Well, all's well, EXCEPT, the "Range" in miles of gasoline in tank...

When I fill the truck, it says I have a range of 590 miles--Ahhhhh, NO way...

Usually it said 420 or there about after fill up, before battery change...

Any thoughts--Is there a reset on it...

Thanks...BCB

... ... ... ✌️ ...

 

It’s fine. It will recalibrate.

 

@Tyman is correct, it will recalibrate.
Might take 3 or 4 tankfuls of gas until the ECU figures your average MPG..

How do you reset it?
You reset it when you disconnected the battery..

You can also press and hold the ENTER button on the steering wheel to reset it.

 

As stated, it will recalibrate, but if you'd like to change your battery seamlessly next time, if you have a jumper back or another battery you can connect the cable to the power and ground leads before disconnecting the battery and make sure they stay connected until the new battery is connected.

 

WoW, that was quick...

I was hoping it would reset once it figured out what type of average mileage I get...

Sure wish it got 590 miles from a full tank of gasoline...

Thanks All Who Replied...

... ... ... ✌️ ...

 

My 26 gallon tank will read over 400 with a reset.
It comes down to around 315 after a couple weeks..

 

How many people even look at this? I did once out curiosity when I drove 2 different routes to and from hunting ranch.

 

Welcome to the forum @BCB. As noted the computer will recalibrate over a short period of time.

However, for your awareness these trucks are sensitive to battery issues and can start doing weird things when the battery starts to go. Otherwise don’t be afraid to disconnect or connect the battery when needed.

 

Three tanks of gasoline and no re-calibration...

Maybe takes more tanks of gasoline?

... ... ... ✌️ ...

 

What happens is your previous average mpg gets cleared after removing power supply. Computer doesn't see what to base remaining miles off, so it defaults to programmed cruise range. It is most certainly possible to get that range if you immediately jump on the freeway and do 60mph on your way to...where ever.

That's a 38gallon tank, yes?

 

My solution to being lied to repeatedly is to merely ignore the source.

 

I don't understand that statement...

So, you must know the correct answer if you know I'm be lied to?

... ... ... ✌️ ...

 

Simple, dear Watson. If on fill-up, your instruments keep telling you that you can drive 200 miles farther than you know it'll really go, simply ignore the instrument.

I refer you to the @Stumpjumper post above.

 

Well, thank-you Sherlock…


But I think I will research this issue a bit further as I have never taken the simple way out, that being—Just To Ignore Something…


Also called “The-Ostrich’s-Head-In-The-Sand Philosophy”


But I _Do_ appreciate your efforts to solve my concern…


... ... ... ✌️ ...

 

I tend to refer to it as obsessing over trivial matters, but .....

Press on, young'un.

 

OP, ECU computes that range value based on running fuel consumption average and fuel sender position. It’s giving accurate information based on what it knows.

If you’re a math and science guy, think in terms of the statistical laws of small sample sizes versus large sample sizes. In the short term you may see greater volatility in range values if you do a lot of varied driving. It will get more consistent with more sampling data over time. For now, enjoy your awesome fuel economy.

 

Yep, a science degree post-Uncle Sam over ½ century ago and with that went some math and a couple of statistics courses…



I understand the representative samples to make the calculations worthwhile…



I just thought the computer would use the mpg each fill-up and do the math. And, as more fill-ups occurred, the range per tankful would become more accurate. But apparently it doesn’t work that way…



Yet, when I purchased this Tundra new, it had the range calculated to what was pretty darn accurate without many, likely only 1, tankful and < 75 miles on it or thereabout. Maybe that was preset at the factory as they know the gas mileage the vehicle is likely to get and that range changed with time and fill-ups and became more representative of my driving conditions and the way I drive…



I still continue to think there may be something wrong with the computer or whatever does the calculations…



I guess time will tell the tale…



... ... ... ✌️ ...