Thanks for taking the time and effort to create that video. In this case, it appears that the Workshop Manual is either incorrect or not updated for the newer models years. Sorry for the conflicting information. I’m interested in understanding how the system is able to determine the position of each sensor, that is impressive.
I have a few guesses on this, all very much just guesses. The following is the route I would look into first if I was putting together a system to do this.
One potential answer is a TPMS sensor at each wheel location. But you would think that would be clear in the manual, and that would increase complexity, probability of failure, and cost, so lets shelve that one for right now and think of other techniques that might work. Lets assume the system cannot directly measure the location of the TPMS IDs and must derive the location some other way.
I have noticed that the drive route after a tire rotation seems to impact how quickly the system identifies which tire is where. Routes with more and tighter turns and stops seem to finish finding the tire locations fastest.
What happens when you turn corners? All 4 tires turn at different rates. Because the system knows the steering turning angle it could calculate the projected speed ratios of all 4 tire locations in real time. And the actual wheel speeds can be sensed by the ABS wheel speed sensors. But that is only part of the puzzle, that still does not tie a specific TPMS ID number to a specific location.
What changes with tire pressure? The rolling diameter of the tire, lower pressure equals smaller rolling diameter and higher wheel rotation rates.
If the computer only knows that TPMS ID #1 is 39 PSI, TPMS ID #2 is 37 PSI, TPMS ID #3 is 34 PSI, and TPMS #4 is 33 PSI, then, assuming matching tires on all 4 corners, it knows that going straight down the road #1 will turn slowest, #2 will be next fastest, #3 will be next, and #4 will turn fastest. Even if you have all 4 tires set to the same cold pressure there will be different heating on each corner, and so the pressure will not stay the same all the time.
Combine the ability to predict relative roll rates under various conditions with the speed sensor in each tire location and that might allow the computer to calculate what tire is where, even using a single TPMS receiver.
Maybe.
And such a technique may also explain why the manual training mode exists and is in the manual. Mismatched or staggered tires may confuse the system and never arrive at the correct locations for tires. The computer may contain logic along the lines of "if manually trained ignore calculations of wheel location" or something like that.
T!
