I Found A New "button"

[chemistken]

It seems, yet again I had a tire light come on. I couldn't reset it. And all the tires had the correct pressure. There is a button on the passengers side under the glove box. If somebody accidentally pushes it the car looks for some new tired (I'm not sure what that means) and if it doesn't find them the light comes on.

Why on earth did Lexus put the button there where it could be accidentally (by my wife) depressed?

Ken

[NeoN]

good writeup, maybe we should ask the dealer what that button does, they should have a better idea

[Gryphon]

I believe that the button you are referring to is the on/off button for the power rear door, most likely a safety feature for children. It's described on page of 23 of the 2007 RX400h Owner's Manual.

The tire pressure warning system is controlled with buttons below the steering column.

Tom

[chemistken]

I believe that the button you are referring to is the on/off button for the power rear door, most likely a safety feature for children. It's described on page of 23 of the 2007 RX400h Owner's Manual.

The tire pressure warning system is controlled with buttons below the steering column.

Tom

I believe you are wrong...but I will check it out later today. Maybe I believed the dealer too quickly!

Ken

[John Francis]

Check the main user manual. It has to do with resetting the tire pressure sensors. I'd dig out a page reference, but I'm too lazy.

[chemistken]

I believe that the button you are referring to is the on/off button for the power rear door, most likely a safety feature for children. It's described on page of 23 of the 2007 RX400h Owner's Manual.

The tire pressure warning system is controlled with buttons below the steering column.

Tom

The button you refer to (page 23) is in/on the side of the glove box and controls the power rear door. It has nothing to do with tire pressure. Look under the glove box and you willsee the button that relates to tire pressure.

It was a very stupid place to put the button.

Ken

[Gryphon]

Ken, I have no need to defend Lexus' RX design, but for my purposes the location of the button has not been a problem in either of our two 400h's which are both 18 months old. I can't think of a more appropriate place for a button that may be used twice/year at the most.

I think the button is actually a nifty idea as it apparently allows an owner to have summer and winter tires/wheels and to recognize both sets of ID codes with nothing more than pushing a button.

FYI this is explained quite well on page 311 of the 2007 Owner's Manual.

Tom

[JeffDonnelly]

Ours came on and it was the SPARE

[Jim Clark]

I just got the manual out and checked the buttons inside the car. The button below the steering column up in the footwell is for resetting tire pressure monitor (TPM). It must be done at cold pressure. That determines the value at which the system works. Tires pressure increases quickly when driving as the tires warm up. So if the light comes on when driving, the pressure has fallen below cold tire pressure so it has dropped a number of pounds, not sure how many pounds the pressure increases when warm, but I bet it's at least 3-4 pounds, maybe more.

The second button related to the TPM is for switching from a "main" set of tires to a "2nd" set of tires. This is for people who run summer and winter tires. It is located under the glove box in the footwell. I believe the ID code for the 2nd tire set must be initialized by the dealer.

Both those buttons have protection against being accidentally pushed (they are recessed).

The third button mentioned is on the left side of the glovebox (must open the glovebox to get to it). That one deactivates the rear power door.

The people who mentioned problems were with the spare. Since the system operates at the cold tire pressure level, and the spare doesn't warm up when driving, the spare should probably be inflated to a few pounds above the cold pressure level of the running tires.

BTW, the ONLY way to set proper cold pressure level is to have a portable air pump at home and a good accurate tire pressure gauge. Tires will warm up with just a few miles of driving and after reaching running temperature take 3 hours to cool down. I actually have three air pumps. My newest one came from Costco and was inexpensive. It has a very accurate digital pressure gauge, runs off car power, and is compact enough to keep in the car.

This is the one I use:

http://www.buytheworld.com/prod2015-Bon_Ai...Compressor.html

[tommygunn]

The second set of TPMS, used with a second set of wheels, MUST be initializied by the dealer. I just found this out Friday of last week. I had started a thread about going with a larger set of tires for winter. I ended up sticking with OEM size, and am happy about it. Once changed to the second set though, the tire sensor light would not go out, or change, no matter which button I pushed. One trip to the dealer, and $110.00 later, all is good again. <_<

I thought the cost was WAY too much for about 20 minutes of work, but ......

[ethridgedsb]

Thanks for the info on the Main/2nd button underneather the passenger side, just below the glovebox on my 09 RX 350. This was accidentally depressed and caused the Low Tire Pressure warning light to illuminate as flashing for 10 or so blinks and then turning to a constant on condition. As soon as I switched the button back out to "Main" the TPMS light went out!!

Thank you