lesz

Did you rotate the tires yourself, or did a dealer do the rotation? If you had the rotation done at a dealer (or even a tire shop) and if re-initializing the TPMS is a part of their routine when doing rotations, your test will be meaningless. On the other hand, if you did the rotation yourself and know for sure that the TPMS was not re-initialized, your test result will tell whether or not the system needs to be re-initialized after a rotation.

With maintenance reminders now common on most cars, service departments now regularly re-set the maintenance reminders when they do oil changes. With TPMSs now becoming common, I wouldn't be surprised if they are now also re-initializing the systems when they do a rotation.

Interapid

I did it myself. Im a bit old fashion about maintenance. Thats why I have all these questions. LOL

gamma742

I look forward to hearing your test Interapid.. I hope Lesz & Mike are right but when you get to a filling station with an air station it should be a simple test.

lesz

In that case, I, too, will be interested in seeing your results.

On my 2005 GX, there is a less sophisticated version of a TPMS. It doesn't tell the pressures at individual tires. Instead, it just throws a warning light on the dash if the pressure in any tire is low, and you have to manually check each tire, including the spare, to determine which tire has low pressure. The manual for that GX does not say anything about re-initializing the TPMS after rotations. Considering that the manual for the ES with a newer generation TPMS does say to re-initialize after a rotation, that is a part of what makes me think that part of the purpose of the re-initialization is to make sure that the system is showing pressures with the proper tire orientation. Thus, it will be good to see your results to see if that is correct.

The service manager at the Toyota dealership where I have maintenance done has told me that, after doing a rotation, they do re-initialize the system. So, there must be some purpose in doing so, and that is why, even though the Toyota dealer supposedly is re-initializing the TPMS after doing a rotation, I have also made it a practice to re-initialization myself after I leave the dealership just to make sure that it has actually been done.

Interapid

Well I ran a test yesterday. Results not totally conclusive. A bit of background: 2017 ES350 UL bought new one year ago. Now has 18,500 miles. At 5,000 and 10,000 took to dealer for free rotation, rotation and oil change. At 15,000 I rotated tires myself and started wondering if I needed to reset something or if the car was smart enough to figure out which tire was on which corner as concerning the tire pressure read out. Last night I looked at the readout and the left rear was reading 32. The rest were 31. So I over filled the LR to 38 and then the reading on the info screen said LR:38. So it knows the correct wheel right now. So I can assume either the car knows what it is doing or the dealer did not re-initialize the system. I will know for sure the next time I rotate the tires at 20,000 (without re-initializing) and re-post the results.

Jets

You guys are reading into it. You only have to initialize if you want to change the stored benchmark inflation pressure. If all 4 tires use 33, for example, you do not need to reinitialize with the button. You only initialize if you want the default tire pressure to change.
The tire position is automatically registered when the ignition is cycled.
This is also from the manual(2018 ES):
"When rotating the tires
Make sure that the engine switch is off. If the tires are rotated while the engine switch is in
IGNITION ON mode, the tire position information will not be updated.
If this accidentally occurs, either turn the engine switch to off and then to IGNITION ON
mode, or initialize the system after checking that the tire pressure is properly adjusted."

I think the part about pressing the button after rotation is a leftover in the manual from the older vehicle system that did not specify tire position.

Dave Mac

I've rotated my tires often and the car seems to know where they are after the rotation. Dealer resetting the TPMS might be just BS or maybe it is a good practice after inflating to what they believe to be the correct pressure, although I hope not because they usually overinflate. I do not recall seeing resetting on the list of things done by the dealer or in the maintenance manual.

I had a GMC Denali a couple of years ago with maintenance included (plus tires and wheels too heavy for me to want to handle) and I remember every time they rotated the tires and failed to do a reset the display would be incorrect. And I think that might have even been a dealer only procedure. I'm pretty fanatical on tire pressures and it took me a while to realize what was wrong whenever I adjusted the air pressure and didn't get the result I expected. For both the Lexus and the Denali the TPMS is pretty accurate once it knows where the tires are positioned.

Dave Mac

Interapid

Useful info. Thanks.