DennisMik

When the warning light flashes, that is an indication that the battery inside the wheel sending unit is/has run out of power and needs to be replaced.

Take the car to a tire shop and they have a hand held tester that can "read" the radio signal from the wheel. They will have to check all 5 wheels as the warning light does not tell you which one. But if the tire pressure warning light is not on, I doubt that the shop will be able to detect which one is the problem.

Also shop the tire places for the price. The best place by me is a chain called Discount Tires, $60.95 out the door. But they are not nationwide. The worst place by me is a chain called NTB. They wanted close to $200 for it, higher than the Lexus dealer.

gbiles

I have a 2008 RX400h, and on a long highway trip with my wife and the TPMS light suddenly came on solid (not flashing) with a Yellow triangle indicating the sensor needed to be checked. I pulled off and checked all tire pressures inlcuding spare. All were okay. I tried to do the reset under the steering wheel and was about to resign myself to taking it to the dealer for possibly a new tpms receiver (expensive new but really cheap used - -but I didn't know how to calibrate it). The light has been on for about a month.

Then I came across the post where there was a "primary and secondary" tire button deep underneath the dash on the glove box side . I just went and checked and sure enough, it was pushed in to "secondary". I suspect on the drive, my wife's foot must've pressed it as she moved around in her seat. Phew!!

ukrkoz

Discount Tire just did all four on wife's 2011 RX350.
$349. As they did my Camry 2 yrs ago to the tune of $78 or so for all four, I asked, how come so much difference.
Guy told me that RX has 19 inch wheels, what comes with larger sensor AND that, in this case, they had to remount/rebalance tires, to replace sensors. True or false, donno, I was not there, she didn't watch. But that's what it is.
That in mind, Les Schwab wanted $180 each for Camry.

DennisMik

I'm not sure about that bigger sensor for 19 inch wheels thing. In Lexus parts listings, there is no reference to wheel size, only NAP & Japanese production. And those 2 part numbers have been superseded with the same one number. In the aftermarket parts for the RX, I find listings for 2007 to 2015, 2007 to 2016 and 2007 to 2018, but no wheel size reference.

Jperez90

Hello everyone,

So i just brought a 2007 Lexus RX350 and as i drive, i have this VSC light on on the dashboard. I see that many other models havea TRAC Off button that pretty much takes the VSC light away but apparently mine doesn't have that button. I also have a Tire Pressure light on as well. Could the VSC light be on because of the Tire Pressure light? The VSC light doesn't turn on until i move the car. If i turn the car off then on, the VSC light is not on until i move the car. What do you guys think?

iolmaster

iTrader: (1)

The TPMS light has no interaction with the VSC. They are separate systems. You likely have one or more batteries in the sensors that is triggering the TPMS light.

DennisMik

Winter time means colder temperatures and this means the air pressure in the tires is less. First thing to do is check and inflate the tires if necessary. And definitely check the spare tire, it is monitored like the other 4 tires. I like to use 35 psi on my car.

Try pressing the button that selects the 2nd set of tires - page 307 in the 2007 Owners Manual. Sometimes this gets pressed accidentally and will give you the TPMS light

Then re-calibrate the tire pressure monitoring system (TPMS).
Select which set of tires to monitor - page 307 in the 2007 Owners Manual.
Then re-calibrate the TPMS -See page 306 in the 2007 Owners Manual.
If you only have one set of tires, I would suggest that you calibrate the settings for both tire set positions

link to owner's manual - https://drivers.lexus.com/t3Portal/d...f/OM48699U.pdf

If this does not turn the light off, then you probably have a sensor where the battery is dead or dying. Go the a tire store and they can check the wheel sensors with a hand held tester.

jpw

I went through this a few months ago. I was really exasperated and about to just give up after messing w/mine for almost 6 months. Had taken it to Costco since they have sensors and usually do a good job. They replaced a few sensors and it worked for a few months, then I saw the warning again - took it in and Costco said all of the wheel transmitters were working fine. Later I discovered they didn't know about the spare sensor so I even took it off and they tested it - said it was fine.

Took it in again, and they came out and said they've reset it many times, all transmitters work fine, and that I should take it either to the dealer or a mechanic.

So I just said 'F' it and I'd just live with it. One evening I was bored so I started watching videos about resetting the tpms, which I'd already done quite a few times and the guy mentioned the 'snow tire' switch under the glove compartment.

I didn't think I had that, but for the heck of it I went out and looked and hot DANG, I did have the switch and it was set to snow/other (not sure what he exact wording was). I switched it to 'normal' tires, reset the TPMS system, and it's been working fine with zero warnings for months.

I'm pretty sure my wife accidentally flipped the switch when she was detailing the car - or she just stuffed too much stuff in the footwell when she was shopping or something like that.

gwhizofmdr

Hey all, just to get very specific about the spare tire sensor, is it possible that when the temperature is hovering around just right, the tire pressure goes slightly above and then slightly below the limit, triggering then cancelling the sensor light over and over as the temperature changes slightly?

DennisMik

Basic science - when something get hot, it expands. When it gets cold, it contracts. Air is not exempt from this, so yes, the situation you describe could happen.

But there is something else also happening here. The TPMS will cause the alarm when the air pressure drops below the pressure it was set to monitor. So if the TPMS was set to monitor the tire at 35 psi, the light in the dash will come on if the pressure drops to less than 30 psi. For your scenario, the air pressure in the tire is at the low pressure threshold, not at the the 35 psi and the cold temperature causes the air in the tire to compress, which makes the pressure to drop.

So you need to properly inflate all the tires, including the spare tire and re-initialize the TPMS system.

gwhizofmdr

@DennisMik that's what I thought. I just wasn't sure if the sensor would cancel the warning on its own once the pressure returned to a high enough level. When the sensor returns, it blinks quite a long time before going solid. In this thread, we stated that means one of the sensor batteries is low. So we have a combination of things happening, confusing the diagnosis. This thread seems to have the most information on this topic (based on it showing up at the top of my Google search) Thanks to everyone who contributes to it.