On to the next repair on the make 213k mile 08 RX350 better cheaply for college student project haha. TPMS light is on and 1 out of 3 old sensors (including spare) remaining has died.

Luckily the RX350 takes the exact same TPMS as my 11 Prius and I happen to have 4x old TPMS in hand. Decided to see what it takes to change the battery. Looks like doable until 6/30/26 until the replacement battery obsoletes. Posted finding on priuschat (since TPMS came off my Prius). Anyhow, info for someone wanting to save ~$200 on all 5x RX350 TPMS. One key challenge as noted is may need to open one up to confirm replacement battery in advance so maybe look at the spare. The Prius one has specific molded shapes to clip in this specific 24.5mm battery to hold it in and doesn't rely on the sealant.

https://priuschat.com/threads/tpms-b...cement.259599/

 

For me, I just bought 5 new ones to go w/ new a new wheel/tire combo......For me it wasn't worth the hassle of a hack job.....

 

Yeah, I found BH Sens (German brand) TPMS for like $17 each so probably go with that. TPMS ID programming, scan, and ECU learning can be quite confusing. The ID programming step seems most challenging with premium brands (Autel, BH Sens etc.) all using their own tools. Ideally buy from a source that pre-config TPMS to your car (315/433Mhz, set ID, link ) Scan and ECU learn steps looks can be done with Autel MaxiTPMS.

Recently helping another car that needs 4x tires and TPMS replacement. Trying to get a tire shop to install bring your own TPMS is like pulling teeth. I guess the many blank ID TPMS from online sources probably makes a mess in their installation effort. So tire shops prefer to install theirs with the high marked up margins.

I'll post more soon on untangling all this (315/433Mhz, dual band, ID programming, scan, ECU learn etc)

 

I wonder if it's possible to replace the batteries in the TPMS sensor somehow, I imagine it would be quite invasive to do so. For 17 dollars each that's pretty hard to pass up, though. The Autel MaxiTPMS worked quite well for me when I was at the dealership. It's a little finicky at first, but once you get the hang of it it's not too bad. If the TPMS sensors are dead, as was the case on our 2014 RX, the tool would load forever i.e. softlock itself, making it seem like the tool itself was glitched even though it wasn't

 

The priuschat link I provided in post #1 shows what's required to replace battery. Takes a bit of labor. Furthermore, for the Denso, need to source exact battery shape (more than just 2450 coin cell) to clip and secure into the shell (sealant preferably just for anti-moisture) Original high temp resistant battery from Panasonic is like $4-5 ea + $9 shipping from mouser (Found no other small quantity sources) and going obsolete in 6/26 so won't be possible soon anyways. With high quality replacements at <= $25 (< $20 for BH Sens but need to get ID programmed by seller or $25 for Autel which common maxiTPMS can program ID) Thought a bit about cheaper clones. I'm guessing their chip and battery might be lower quality and likely shorter longevity. Just a guess