Trailer length setup contradiction: OM procedure versus vehicle built-in procedure

When configuring a new trailer to the '22 Tundra, the OM states that the trailer length setting is measured from the hitch ball to the center of the single axle of a single axle trailer. The vehicle setup says to measure from the hitch ball to the rear of the trailer. Which is correct?

And what of the Auto length setting? Does anyone have a reliable explanation of that option's usage? TIA.

 

On a long trip I realized that the auto measure for the trailer sucks, it resets every time you turn the truck off. If you stop and turn the truck off then pull out straight it will not detect the correct length. I deseable the auto and did the length manually, did it to the back of the trailer.
now is just plug and play and I know the length is the same every time.

 

This is good info. Sub'd for answer to OP question since I'll be towing soon.

 

Can’t you save a trailer though? I saved just our camp trailer and figured if I ever had to rent one or something. I would have to re-configure

 

You can have few trailers saved

 

Contacting Toyota Brand Engagement Center yielded this response:

Thank you for contacting Toyota Motor Sales, U.S.A., Inc.

We appreciate the opportunity to address the towing concern you are experiencing with your 2022 Toyota Tundra.

We have looked further into your concern and recommend following the guidelines provided in your Owner's Manual regarding the trailer setup for your 2022 Toyota Tundra.

 

So the "final answer" is hitch ball to center of the axle then?

 

Yesterday I configured my vehicle to that parameter.

 

I did auto length measurement and then saved the trailer. I wish there was a setting to save my 4 pin utility trailer to auto off the back up sensors. I know there is no feedback since it’s not a 7pin but just saying.

 

I wonder if this would work for that

 

My guess is no since there would be no feedback to the truck due the lack of brake controller.

 

My 7 to 4 flat adapter on my utility trailer causes the truck to automatically disable rcta.

 

Ok worth tring with mine then. thanks

 

Same. Thx!