Where is the pressure sensor?

yeah, the sensors are part of the valvestem. you can tell sensors from regular valvestems, there's a box-like thing on the inside that's the actual sensor unit.

tire shops have had enough experience by now to know what the sensors are. make sure you tell them they're there, they can be damaged if the shop doesn't know.

 

<div class='quotetop'>QUOTE(galaxee @ Nov 27 2006, 09:22 PM) [snapback]354696[/snapback]</div>

So how does the pressure sensor information get communicated to the car? I can't imagine there is a direct wire, that would twist off in a second. Probably not a wireless transmission. Is it a contact point and brush between the wheel and the mount point?

If I purchase a 2nd set of wheels to put snow tires on, do I need to purchase particular valve stems with toyota sensors in them for the system to work? Do most tire shops have these in stock?

 

The Prius tire sensor is attached to the valve stem. It appears to be wireless communication. I took all 4 sensors off my prius wheels when I mounted a set of snow tires last week. I plan to buy new wheels in the spring and have the sensors put on them. A new set of sensors costs a whopping $480. I see no reason to buy new sensors because I've always done fine without them in the past. When you take the sensors off, an amber warning light appears on the right side of the console. It blinks for a minute or two and then stays steady. I disregard this light now but you could put a black piece of electrical tape over the symbol if the light distracts you. I will try to put an attached picture of a sensor on this note. Jim

 

<div class='quotetop'>QUOTE(healthizez @ Dec 31 2006, 09:58 AM) [snapback]368908[/snapback]</div>

can you get an X-ray of your sensors ?
(ask your dentist-who has small films or even digital imaging)

 

<div class='quotetop'>QUOTE(healthizez @ Dec 31 2006, 07:58 AM) [snapback]368908[/snapback]</div>

Way cool, thanks for the picture too. I'm guessing these each have a battery in them. I wonder how long it lasts and if it is replaceable of if it requires replacing the whole unit at Toyota's insane cost.

 

<div class='quotetop'>QUOTE(mtsarpilot @ Dec 31 2006, 06:47 PM) [snapback]369083[/snapback]</div>

We've got the same feature on our 2000 Sienna and have not had issues with it yet (6 1/2 years later). I don't know whether it works the same way as the Prius', but I assume it's at least similar. We've had tires replaced many times, have never mentioned it, but have not had problems either.

It's a nice feature to have, very handy.

<div class='quotetop'>QUOTE(healthizez @ Dec 31 2006, 09:58 AM) [snapback]368908[/snapback]</div>

Do you have the Toyota part number for that warning light attenuation tape?

 

[ Do you have the Toyota part number for that warning light attenuation tape?
[/quote]

Heck no! The warning light attenuation tape that Toyota sells is measured in milimeters and I didn't think I could figure out how many mms I'd need when I'd go to cut it. I just bought good old american electrical tape and cut 1/4 inch!!!! :blink: :lol:

 

<div class='quotetop'>QUOTE(healthizez @ Dec 31 2006, 05:29 PM) [snapback]369107[/snapback]</div>

just put the 4 sensors in a bag and put them in the hatch and your light will go out. No tape needed.

 

<div class='quotetop'>QUOTE(Frank Hudon @ Dec 31 2006, 11:56 PM) [snapback]369159[/snapback]</div>

Tried that...the sensors registered low tire inflation...showed a steady low pressure reading.

 

<div class='quotetop'>QUOTE(healthizez @ Jan 1 2007, 12:56 AM) [snapback]369177[/snapback]</div>

Pump the bag up to 35 psi!

Seriously, though, I thought the low tire light would come on if differences in tire pressure were detected, so if they were all the same (zero), there would be no difference. Have you tried resetting the tire pressure warning light with the button below the steering column per the manual?

Check this thread for more info.

 

The battery is not replaceable. It should last 10 years or so. Most of us will have a different car by then. The sensors are wireless transmission type. The receiving unit can only handle four sensors. If you have to change one of them it has to be reprogrammed for the new one - they remove all sensors from it's memory, then reprogram the old three back and the new one.

I suspect by the time the batteries start to fail an aftermarket sensor/tire stem will be available for under $50. They are now required on all new cars in the US and Canada, not sure about Europe. This will generate a huge market which will encourage aftermarket manufs. to produce them.

One funny thing about the sensors is if you park next to another vehicle with the same brand of sensors it can confuse your receiver and turn on the light.

 

<div class='quotetop'>QUOTE(David Beale @ Jan 1 2007, 10:13 AM) [snapback]369252[/snapback]</div>

I would not think parking next to another vehicle with the same brand sensors would make any differences for the reasons you stated in your own comments. Each sensor has a unique "code" that it transmits via wireless and your own receiver is told to ignore all codes except those that are programmed into your car computer.

<_< As I speculate now, however, perhaps if enough of these sensors are in close proximity to each other it can block the RF signals from your own sensors causing the light to come on. :lol:

Thanks for the comments!

 

<div class='quotetop'>QUOTE(PA @ Jan 1 2007, 10:48 AM) [snapback]369226[/snapback]</div>

Well, we are all learning things about our Prii. I hadn't used that reset button before but will now. I recommend that everyone read the thread just mentioned. "Galaxee" is a very knowledgeable guy. I found out that I have to find a set of new wheels that these sensors can fit onto. The sensors have to be the right angle to fit the rims. I am posting another picture to show the sensor angle. The options for wheels gets narrower and narrower.]
I just tried the reset button with the sensors in the "jockeybox" . I depressed and held the button until the light blinked thrice but the light did not go out. There must be an absolute low pressure that you can reset the sensors to and have the light go out. Obviously, you can't reset to zero unless someone has an additional idea. I bet "Galaxee" B) has an answer.

 

Here's a sobering thought:

Reprinted without permission from Bruce Schneier's web page http://www.schneier.com/blog/ :

Tracking Automobiles Through their Tires

Automobile tires are now being outfitted with RFID transmitters:

Schrader Bridgeport is the market leader in direct Tire Pressure Monitoring Systems. Direct TPMS use pressure sensors inside each tire to transmit data to a dashboard display alerting drivers to tire pressure problems.

I'll bet anything you can track cars with them, just as you can track some joggers by their sneakers.

As I said before, the people who are designing these systems are putting 'zero thought into security and privacy issues. Unless we enact some sort of broad law requiring companies to add security into these sorts of systems, companies will continue to produce devices that erode our privacy through new technologies. Not on purpose, not because they're evil -- just because it's easier to ignore the externality than to worry about it.'

 

<div class='quotetop'>QUOTE(dulcimer @ Nov 27 2006, 09:13 PM) [snapback]354644[/snapback]</div>

Our cars have STEEL valve stems instead of rubber. Do not let anyone mess with them. The sensor system works with them. I recently had the low tire pressure dash graphic light up. Sure enough, there was 20 lbs. of air in the RR tire. I brought the car to Tire Kingdom where I have a road hazard plan. They wouldn't drive the car so I drove it around the bldg. and they jacked it up using a floor jack. They had NO concept on how to start or drive a Prius. I showed them the "key" and they looked scared. They patched the tire and I left.

Motorcycles and race cars usually have steel valve stems. They rarely need replacement.

 

<div class='quotetop'>QUOTE(Rick Auricchio @ Jan 1 2007, 12:47 PM) [snapback]369286[/snapback]</div>

Thank you for your comments! It reminded of Aaron Russo's recent film. While he investigated primarily the legality of current income tax laws, his findings took him well beyond the initial investigation for some very sobering thoughts on this type stuff. He believes we will ALL be chipped like a dog with RFDI chips and very soon! Here is a link to some very interesting views on this topic! You can decide for yourself if this is being done with evil intentions or not.

Like it or not, Big Brother is watching!

Video: Aaron Russo's America, Freedom to Fascism

 

So you think the RFID signal violates privacy? Well it has a range of around 20 ft on a good day. You know of course they can see your car for at least 900 ft, much further if they're young. They can read your licence plate, and can get info from that as well, more than from a tire pressure sensor.

People need to chill out!

 

<div class='quotetop'>QUOTE(healthizez @ Jan 1 2007, 02:12 PM) [snapback]369283[/snapback]</div>

being that your sensors are not in the tires, they are reading zero pressure. you're going to be stuck with that light as long as that situation continues.

galaxee's husband is a hybrid tech, so he's the knowledgeable one

 

<div class='quotetop'>QUOTE(David Beale @ Jan 2 2007, 08:30 AM) [snapback]369555[/snapback]</div>

David, thank you for your opinion but I don't think "range of around 20 feet" is really an issue. One only needs a "reader" in close proximity to the tire. A simple "reader" only need be installed in say a highway, parking lot, airport, etc. for example and before you know it, the government will know at any time of day or night your route of driving, how fast you got there, your current whereabouts, etc. With little imagination you could easily see where this could go if "officials" wanted to use this for evil intensions. I believe Hitler used this on the Jews to keep track of them except without the electronics not available at that time. I believe all who survived the consentration camps and are still alive can still show you their own "numbers" tatooed if you wish to see proof. I wish I had your optimism for mankind but I see too many examples in history otherwise. Best wishes.