Harold57

When my tires are low on pressure, the light comes on. The light goes off once I bring the air pressure back into spec. My tires have never dropped low enough to cause an audible alarm to go off, if that is how it works.

ShawnOk

iTrader: (1)

So here's my experience. If a sensor is bad or no longer tranmitting a stong enough signal, I get a steady light on the dashboard. If my tire gets low on air, I get a steady light on the dash. If there is catastrophic failure (huge loss of air pressure), I got an audible warning and flashing light on the dash (Happened to me while driving to Louisiana and had a blow out). That being said, I don't know what happens in a situation where the sensor has stopped transmitting, and then additionally a tire becomes low (slightly below threshold or total failure). Even though it wasn't a full answer to your question, I hope it helped somewhat.

jasone36

Thanks for the feedback, ShawnOK and Harold, and everyone else.

It looks like we just don't have a clear answer to this question.

Because of the ambiguity, I plan on keeping the TPMS system plugged in, even though the orange dash light is on... maybe there is some value to be derived, after all.

We'll see what happens.

Harold57

You might call the Lexus service department. These sensors shouldn't be any different than is on the other models and the monitor is probably the same in earlier cars. So their technicians (and hopefully the service advisors) ought to be able to tell you how they work. Lexus really needs a customer service line for questions like these, or at least a FAQ on-line.

nomods4me

could someone post the part numbers for the 4 different color sensors?

thanx

Bgw70

google and eBay make it simple to find answers...
http://www.ebay.com/itm/LEXUS-OEM-FACTORY-TIRE-PRESSURE-SENSOR-SET-2002-2006-SC430-/332008846523?_trksid=p2141725.m3641.l6368

nomods4me

yeah, I found that listing right after posting the question
sorry...

I'm definitely thinking of replacing them all when I get new tires and then they should be good for a very long time since my light has started coming on and the tires are all inflated properly

Bgw70

does the 2005 SC430 have a reset button for the TPMS?
if not make sure the tire place can indeed reset the sensors unless you are taking it to Toyota or Lexus...then again, if you have TechStream you are all set.
BTW, that is a really good price, I paid $70 on Rockauto.

nomods4me

RockAuto $276 + $13 shipping so the ebay is a few bucks cheaper

did you replace all 4 at once? My thinking is that I won't have to think about them again for a long long time in a world far far away

Caflashbob

My local Costco replaced all four of mine on our solara for $265 installed and joined to the computer

OBP

For the Sc430, most Costcos and Discount Tire shops cannot do the programming into the computer. Need Techstream or you can go back to Lexus. Unique problem for the Sc430. Been through this twice over and doing it again now for my after market rims. Local shops can install the TPMS though and the eBay seller mentioned above is reliable ( just bought my second set from them) but the light will be lit until the programming/activation gets done.

Bgw70

yes, replacing all four is a good idea for the reason you stated.
I did not because I have tech stream and my local Discount Tire installs them at no charge. I then sit in my car and program the sensor.

nomods4me

since they are all programmed by a serial number, is it really necessary to make sure you get one of each color or can you just put in 4 of the same color and program the numbers?

Bgw70

i don't remember exactly why but I think it is either different frequencies or addresses.
if you could use all the same color, I think they would have come that way.

iolmaster

iTrader: (1)

You have to have one of each color. This is just for 02 to 06. It is my understanding that from 07 on they used a different system that relied on serial numbers, not colors.