Range estimate

Blew a fuse switching out of lights yesterday. My range has showed as 401 since I bought the truck used. It has a 38gal tank. I always thought it was low but figured toyota didn't adjust range for larger tank.

After I blew the fuse, range went up to 608.

Any ideas as to what/why this happened?

 

Here is a picture.

 

System reset. Your truck should learn over the next few tanks. You'll be back at 401 in a bit. Don't sweat it. Guys replacing batteries see this and periodically post about it also.

 

I see. Many apologies, I didn't search other posts very hard. Thanks for the info!

 

Which fuse blew? Know which one could help isolate what ecu lost power to make the data reset.

 

It reset, will happen anytime power is cut, fuse, battery replacement, etc. It will come back down, relearn, after a tank of gas or two.

 

Mine was like that when I bought it new with only a handful of miles, in a few days it will go back to ~400

 

It was FR FOG. I accidentally blew it when I was switching out my fogs. Put in another 15 and it was good to go. But range reset which I didn’t know about.

 

Is that a normal range for a 38gal tank?

 

Seems to be. Mine has the 38 and that's typically what it says.

 

All you did was blow the fuse and then replace it? Never disconnected the battery ect?
If that fuse blowing was the only "power loss" it somehow reset your distance to empty as well. I am going to look at the wiring diagrams to see what all that fuse powers

 

Now you have me worried…..please let me know what you find. Everything in my truck seems to be working OK

 

When it comes to range, you will not worry about it soon enough. You will see this.....

 

HA! I have to get myself that cup!

 

If yours is working correctly no worries. That fuse listed really only powers the fog lights but that circuit does has one wire going into the engine ECU. I assume maybe loosing power on that wire reset your range value.

I am still trying to really figure out how the Range value calculates. Toyota says its internal in the cluster but from my testing I think the Engine ECU is sending a fuel used signal or something to the cluster to allow it to calculate the starting value. I have everything reverse engineered on my 2018 benchtop cluster except the Range. I cant not figure out how to get it to initialize a range value of 608 miles or whatever. I think once it has a starting value the cluster starts to "correct" it based on driving behavior.

My just stays blank with no number no matter what signal I send it.

 

From what I've read, The range prediction is based on past average mpg, and it changes as you progress through the tank. So if your ave mpg is low during the first part of the tank, the system assumes that will remain true for the remainder of the tank.

 

Just get yourself a lift and 35's, warm up the card and don't look at it again.