Tire pressure light won't stay off

=============== Excuse me for asking the obvious, but are all the tires the same exact size? The indicator reads tiny differences in speed based on the circumference of the tire with lower pressure being less.

Wow thats the least obvious question i'd have thought. How do these tyre pressure sensors work, via the wheel speed sensors for the ABS? Measure a different rotation rate and assume the pressure must be low?

Exactly! When they get low the contact patch gets bigger, the axle goes lower, and the rotation slows down just a bit. And the ABS sensor is getting 50 or more pulses per revolution.

The tires need to be the same exact brand and model, and roughly the same wear level, so the circumferences match. (IOW, stay up on your tire rotations so they wear evenly, and change them as a set.) The computer can only allow for very minor differences.

It's a pain when this stuff happens, but the 'count the rotations' dodge makes it cheap to implement a TPM system when the ABS Sensors are already there. Much less to implement than any electronic solutions with pressure monitoring transmitters on or inside the wheels and a RF receiver on the car.

-->--

The tire pressure sensors use the ABS wheel speed sensors, and if one tire is different, then it assumes the pressure is low.

You should ask your dealer to reset it if you still have the warranty. Last time I failed to reset this stupid light after I followed the instructions in the owner's manual several time, I took it back to my dealer and they showed me a complex procedure, keep pushing the reset button until the light stays on and then flash 3 times, now turn off the engine and restart it immediately, which is not mentioned in my owner's manual at all. The light has not come back on since. I guess he probably disabled it instead of reset it.

Btw, mine is a 05 Highlander LTD. I am not sure that the same procedure can be applied to your 04 Solara because my 99 Sienna did not require this complex procedure to reset the light, which is keeping pushing the reset button until it goes off, that is mentioned in the owner's manual.

Are the tires all the same size, and the same brand.

The tire inflation condition is calculated by the revolution of the tires themselves. If one tire is consistantly rolling along at a slightly differentn speed than the others, then it is assumed that the air pressure on that tire is off.

If the tires are worn, or from different makers, or are different sizes, then this can trigger a low pressure indication.

In a nutshell, yes. They work off of hte wheel speed sensors.

In another post, the poster says he bought a new 06 Tacoma and wants to put his 03 wheels with new tires on it, but he is stumbling with tire pressure sensor issues. His dealer suggested that the rims will not fit the system, but I'm not sure that his dealer is right. I can't think of any reason why 4 same size tires won't work in a system that looks at the ABS Speed Sensors.

I like the system on my '92 Corolla Wagon a hell of a lot better.

I pull out my tire gauge and check the pressure.

No fancy system to go bad...

Works every time....LOL

The 06 Tacoma uses tire stem pressure monitors that transmit a signal - it also monitors the spare! If the solara uses this type of system then possibly there's a faulty sensor.

On my new Odyssey, it gives the exact pressure read out of each tire. Very impressive.

I used a tire guaged and filled up my Odyssey. I pushed the button on the Odyssey and it read exactly what I had put in by my gauge. A few weeks later I brought it to my dealer for an oil change. As I started to drive off I pushed the check pressure button and discovered the helpful tech had lowered my pressures to Accord specs. I drove it back in and let them fix it and then showed them on the door what the Odyssey required. And they wonder why customers have attitudes.

For the original poster: There is a reset procedure which is more than just pushing the reset button. I think it's like this, but maybe Ray O. will correct me if I am wrong:

Engine off Ignition on Hold down reset button until it flashes 3 times Turn off ignition Then start engine, and the light should stay off.

WingNut

What sort of message does it display, Right Front Tire Low, or just that one of them is low?

I'm not sure that I'd appreciate a system that effectively told me to check all of the tires for proper inflation. I might find pleasure in checking a particular tire, but a blanket warning is useless to me, and it would be a system that I would never buy on purpose.

There has to be a simple way to defeat such a system.

All vehicles sold in the U.S. will be required by law to have tire pressure monitors soon, I forget exactly when.

Rather than trying to defeat the system, the OP only has to reset the monitors.

Has your transmission failed yet?

Now that is impressive....LOL

I see how you become popular with everyone!

What a grouch....

I have a pet peeve at my Toyota dealer. They forget my instructions to put 3000 miles on my oil change stickers.

Instead of being an ass hole, like you, I go back in grinning to the Service Manager. He KNOWS what it is and goes to get another sticker....HIMSELF...LOL

I now KNOW why you have so much trouble with dealers and your cars....LOL

I think his tranny will be OK.

It's the interior noises that are likely to occur later on that will cause him to squawk, just like with his Avalon. LOL!

me thinks he squawks just to hear himself squawk....

Hell he GAVE an in law a Crapsler...what kind of a guy is that?

LOL

Sounds like some government safety mavens somewhere have way too much time on their hands. I can understand how tire pressure monitors might be a desirable convenience option in high-end cars, but their being mandatory across the board is a bit much. Anyone whos'capable of driving a car is capable of checking the tire pressure the old-fashioned way. Why is it assumed that someone who wouldn't bother doing that would be any more attentive to tire pressure if it were presented by an electronic display? "Ahh, what the hell. The car still handles okay. I'll worry about the tire pressure later."

I remember when the only vehicle that had that feature was the Hummer H1 -- a legacy of its military origins.

Geoff