MadHungari

My TPWL is on—I checked the pressure(s) and all tires are ok. I then read the owner’s manual and it raised (for me) more questions than it answered. Here they are:

(1) The manual says “If the warning light comes on or blinks even after tire pressure adjustment, it is probable that you have a flat tire.” Does this mean that with an indicated 35 psi in a tire, the tire can be flat? That does not seem possible. Is it?

(2) The manual goes on to say “If you cannot verify the pressure soon, go to the nearest Lexus dealer . . .” Please note the use of “verify” rather than “test” or “check,” etc. How does one verify the pressure except by using a second gauge to do a validity/reliability check on the first gauge (which indicates each tire is ok)?

(3) And finally, do these instructions apply if run-flats have been replaced by regular tires?

So there it is. I’m confused. Do I just have a flat tire, a system malfunction, or what? Your assistance will be appreciated.

del3180

You can check out some info here...
http://us.lexusownersclub.com/forums...howtopic=47260

I don't know what year your SC430 is, but the TPMS sensor batteries only last 8-10 years, after which you'll have to buy new sensors as the batteries cannot be changed (they're sealed in there).

Habious

Battery life in the sensors is more like 4-6 years.

I've had all 4 of my sensors from my 2003 fail...dead batteries.

For the TPMS light...

If the light comes ON...you either have:

(A) a slightly low tire
(B) a bad sensor (probably a dead battery but, if one of the sensors fails for ANY reason, you'll get the light)

If you check the tires with a good tire pressure gauge and they all look fine...it's (B).

If the light is BLINKING, and accompanied by a "Bing, Bing, Bing" (like your door is open), you've got a flat tire.

MadHungari

Thanks for the input. It appears to be, as I suspected, a system failure (old sensors on my '03 car). Time to down-load the "How to disable tire-pressure monitoring (TPM) system" link.

JerryB

Hi Mad,

When I disabled mine I did NOT remove the shifter handle. Just put it all of the way to the rear and it gave sufficient room to get to the two connectors.

Good luck,

Jerry Baumchen

tfeni52355

Bought an aftermarket TPMS system from Orange Electronics. Best move I ever made to solve this problem. I get PSI readout on each tire and can set the PSI alarm to a pressure that warns me in advance of a low pressure situation. Of course nothing will warn of a catastrophic failure of a tire. I set the alarm at 30 PSI well in advance of the factory 26 PSI. The unit plugs into the 12V outlet in the bottom of the console box and the digital readout is mounted on the side of the console by the drivers knee. That way you can still see the pressures without making the dash a mess....