Tire pressure sensors

[teacherboy]

I just had my tires replaced yesterday and now my pressure sensor light stays on. When I start the vehicle it goes off after the initial startup then comes on in a second or so. Tire pressures are fine, even in the spare. Do I need to reset something? The manual is a little vague on it. Thanks in advance.

 

[josh220]

Well it could be one of 2 things. Worst case scenario, is that the place that installed the tires didn't know what they were doing, and broke one of the sensors. If that happened you might want to take it up with them to pay for it because it will be a bit pricey.

I don't know what year your 4runner is, but if it's a 4th gen, are they all at 32 psi? Since you said they are all at the pressure recommended in the manual, the sensor would be the only thing I could think of.

I had the same problem, but it turned out to be the spare that set off the light. You might just want to re-check all of the pressures 2-3 times on each tire.

 

[teacherboy]

My 4Runner is an 05. I was afraid it may be a sensor. It doesn't blink it stays on. Are they mounted to the valve stem? How pricey are they? Thanks

 

[josh220]

I'm not sure since mine turned out to be just the spare being at like 24psi. The dealer told me that tire shops breaking the sensor isn't that uncommon, and that they can be pretty expensive. Just call a dealer around you and ask them how much it is to replace it. They will usually also charge you for having to hook up their diagnostic computer to check which sensor is out. Then after you get it quoted, you would have to go take it up with the tire store.

But like I said, just check the pressure in all of the tires and make sure they are all at 32, nothing more, nothing less, just to make sure. Even though being off by 1 or 2 shouldn't make a difference.

Also, which tires did you put on, do they require a special PSI that may throw off the sensor?

 

[toto]

The pressure sensor is a part of the valve stem. There's a picture of it in this thread.

The sensors are rumored to be $100 to $150 a piece. That's a pretty expensive screw-up, if that what it is.

First check that all 5 tires are above 27 PSI - that's the level at which the light will come on for low pressure.

Beyond that, a Toyota dealer could tell you what's wrong with it by plugging in their fancy OBD scan tool.

 

[josh220]

My light went off last night, and I just checked the pressure, and all of them are at about 28.5 psi. Which means at night they are probably going down to about 25 or 26, causing the light to come on. They were at 32 just a few weeks ago before it started getting cold, so maybe you are having the same problem. Hopefully that's all that it is.