Has anyone else had their low tire pressure indicator come on..then go off, then back on..and so forth?

I checked the tires, and they are fine.

 

I can't help you but I did put the pressure sensing valve caps on my tires. After six months, I've verified my right rear tire has a slow leak that needs to be topped off every 6-8 weeks and the other tires are fine. For a total cost of $11, it has turned out to be one of my better buys.

BTW, the tire pressure caps must be seated firmly on the valve stem. If you don't have much of a grip, a gripping tool makes sense. They need to be on firm but not smashed down. Someone else reported getting a flat tires from slow leaks and losing one. My experience has been very positive.

Bob Wilson

 

When I first bought the car, as the sales rep was doing the "what the heck is that" shpiel, I asked why the orange light was flashing. It was, of course, the pressure indicator. He was a bit befuddled, messed with it for a bit, then brought it to be fixed.

Next morning, I notice the same light is on and steady (was it on the night before? I don't recall). Checked the tires; front left was a bit low (31 psi) but filling it up didn't shut the light. Brought the car to the dealer, they fiddled with it for a while, and it's off for now.

Not quite the same, but there you are.

 

Three days after taking delivery of our 2006, the tire pressure light came on. I check the tires and sure enough, one was down to 22psi. There was, in fact, a nail in the tire.

It has not come on since then. Have it checked the next time you have your car in for service.

 

I was skeptical about this feature since I don't know what it uses as a sensor on the tires.

Mine came on a while back and i looked at the tires and one had a NAIL with a slow leak but that tire was down quite a bit.

2 weeks later it came on again, i looked at all tires and they looked fine. i tried RESETTING the pressure sensor by holding the button under the steering wheel but that didn't work. It wouldn't stay off. It came on every time i started the car. I have a digital pressure gauge in my car so i walked around and checked all 4 tires.
LF = 31.5
RF = 27
LR = 32
RR = 31.5

so now i'm a BELIEVER. it detected it at 15% loss!
-Logan

 

What pressure is the indicator supposed to come on at?

 

I believe tire pressure sensors are a required feature of all cars as of 2006. Most manufacturers have opted to use information from the ABS system to detect when one tire has low pressure because it will rotate faster than the other three (on average). Systems that work on this principle cannot detect when all four tires are low, so don't count on them. A few systems do use real pressure monitors -- anyone know which method the Prius uses?

I also had a nail in a tire after one week. I had my Dad in the passenger seat looking up what the stupid indicator light meant (kind of an exclamation point surrounded by two brackets, NOT intuitive). Dug around in the glove box, found my pressure gauge, prepared to check all four tires, and heard the right rear hissing away. Of course it was raining...

But this led to one (actually two) useful discovery for new car owners -- you can purchase tire hazard insurance from Goodyear for $10 per tire if you have less than 500 miles on your new vehicle. In my case, the $40 fee even worked retroactively and covered the otherwise $23 repair. Lucky me that I happened to drive into a Goodyear store to get it fixed (I didn't even know I had Goodyear tires at the time).

Second useful discovery -- Goodyear will rotate your tires for free. Only problem is dealing with oil changes and tire rotations at two different locations (since I already purchased two years of oil changes from Toyota).

Silver linings?

-Terence

 

Again, at what pressure does the low pressure indicator come on at?

 

Well, assuming the system works off differential tire rotation speeds, then loganboyd's results indicate the Toyota system is activated at a ?15% differential. So that would be no more than a 4.5-6.0 psi drop, depending on your normal inflation pressure (30-40 psi).

 

So the system doesn't use a minimum pressure before letting you know?