Three transmission pressure switches. Which to replace?
 

https://cimg2.ibsrv.net/gimg/acurazi...bc9f1c40f4.jpg
According to this, there are three switches. Two are numbered 11 and are 28600-RKE-004 or 28600-RAY-013 or 28600-RAY-003 and one is numbered 12 and is 28610-RKE-004 or 28610-RAY-013. If one were to replace these for preventative maintenance, should all three be replaced? If not, which ones should be replaced. And does anyone know exactly what each of these regulates? I read somewhere that #11 regulates 4th gear and #12 regulates 3rd gear but that seems too simple and doesn't explain what the second #11 regulates. I would guess these serve dual duty and also regulate line pressure for other gears. And, the big question for me is, do any of them impact the torque converter lock up?

After glancing at the TC diagram, I am guessing that the #11 switch on the top is regulating the pressure for TC lockup. It looks like the TC is the part bolted to the back of the first diagram.
https://cimg2.ibsrv.net/gimg/acurazi...dedd33d3f1.jpg

The part numbers I bought were 28600-RKE-004 x 2 and 28610-RKE-004

So you did all three then?

I never ended up changing my pressure switches but that would be what you would end up changing.

2x part labeled 11 and 1 label 13. I replaced all 3 after doing 6x3 and the shift is butter smooth now.

What is part #13? And 6x3 seems a bit excessive.

I believe those correspond to the part #s I provided.

If you claim so meaning you never had to go under the RL and drain the ATF. I am pretty sure projektvertx know why its 6x3 and not 3x3, well its should be called 2.6 x 6

For the folks who want to tackle this job I've taken photos to help you identify the location of these switches. In total there are three switches. 2 28600-rke-004 for the 2nd and 4th pressure switches and 1 28610-rke-004 for tue 3rd gear pressure switch. The hardest one to do is the rear. I bought from a brand named Sins on Amazon based on positive reviews. Saved a few bucks over oem.

https://cimg0.ibsrv.net/gimg/acurazi...cf0e328034.jpg
4th pressure switch
https://cimg0.ibsrv.net/gimg/acurazi...bf6dc6df36.jpg
4th pressure switch. must remove air intake box
https://cimg4.ibsrv.net/gimg/acurazi...925659f9ee.jpg
3rd gear pressure switch. access through the driver side wheel well. remove wheel and plastic panel.
https://cimg1.ibsrv.net/gimg/acurazi...f0032b381d.jpg
2nd gear pressure switch. hardest to reach out of the three. took me 2 hours because I used too big of a ratchet..then finally figured out to use a smaller ratchet and was able to make it work. this is behind strut bar. hard to find.
https://cimg9.ibsrv.net/gimg/acurazi...21ffbea9c5.jpg
https://cimg5.ibsrv.net/gimg/acurazi...c676672a44.jpg
2nd gear
https://cimg6.ibsrv.net/gimg/acurazi...262960a40f.jpg
3rd gear
https://cimg8.ibsrv.net/gimg/acurazi...f2bfb14f35.jpg
I used a deep socket 22mm and a 3/8 drive with a 1/2 adapter

the rear one is fun isn't it? lol.


My TL gave me a lot of clue where the switches reside as the TL use the borrow design from the RL.

lol the rear was such a pain and I am not tall enough to have the reach..Glad you have experience with the TL it definitely is almost the same design.