I had a flat a couple of weeks ago and changed to the spare tire. The light came on and stayed on the entire time the spare was on the vehicle. Should have checked the tire pressure on the spare but did not.
The flat needed to be replaced and that took several days to get the new tire, mounted, etc. Now the matching tire is back on the vehicle.
The light went off when my husband replaced the tire, so we thought all was well. It stayed off for several days.
The light is now back on again. We've checked tire pressures on all 5 tires (4 on the vehicle plus the spare). All very close to 30 psi.
Any ideas on what could be wrong? Only other thing I can think of is to stop by the tire store -

Thanks.

2008 RX350

 

I don't have the manual with me, but there is a procedure described therein to 'reset' the tire pressure monitoring system. Maybe you should try that ?

 

Yes - I should have mentioned that. I have used the procedure 3 times to no avail.

Might be a trip to the dealer in my future.....

 

I always inflate the spare tire to 38 psi. You will eliminate it as the possible cause by doing that. If the spare is needed you can deflate it to the proper psi.

 

38! ?? I`d hate to ride with you.

 

38 in the spare should be ok.
Salim

 

Nine times of ten when the tire pressure warning light comes on the culprit is the spare tire. I inflate the SPARE to 38psi and forget about it. The tires that I ride on are inflated to the Manufactures recommended pressure.

 

Ooooooooooo, ok. My Bad. I read that wrong. I thought you were putting 38lbs. in your tires all around.

 

noob Qes: I just my tire pressure monitors/sensors in the mail right now..CaN i get them installed anywhere else besides a lexus dealer? Can they make my light go away+make theses 2nd set? (for is)

thx

 

anyone with input? :S

 

My understanding is that on the RXs previous to 2010, you can have two sets of TPMS with your system. 2010 only allows one set. The manual (again: I don't have it with me) - if I remember correctly - explains this as well as the procedure(s) to follow. I would assume a dealer would know too, as well as a number of tire dealers' places.
I would believe that - subject to the connection with your TMPS system - any reputable tire dealer's place can install them. Give them a call (?) or maybe speak to the people at tirerack.com?

 

lol it is actually for my is250, was too lazy to make another thread in IS section so though I would ask here. I guess I'll call up a tire place and ask tomorrow. thanks for the reply though

 

if the spare is low in PSI. It can trigger the light on the dash. Happened to me.

 

In 2004's the spare has no impact since the pressure is approximated via a sensor on the wheel/rpm.

 

thanks for the info..I didnt know the spare has a sensor....