Driving without Tire Pressure Sensors

At $300 to have them installed, I am inclined to skip the TPS when I buy the snow tire/rim package for the FRS. Anyone else drive without them and is there anything I should be aware of if I do this?

Also, if anyone knows of a steel wheel that will fit this car, I would love to know; Tire Rack does not carry a steel rim for the FRS and Scion wants more for a steel wheel than Tire Rack does for an alloy.

I drove all last winter without TPMS sensors in my snow tires/rims. Just had a little dummy light on all the time. In the spring when I put the factory wheels back on they reconnected without any issue. In my car it was not just the $ to buy the sensors, but the car needs to be programmed at the dealer when switching wheels back and forth if both sets have the sensors. Didn't want to go to the dealer or pay them so I did not get the sensors in my snow wheels.

What is the bolt pattern, size and offset of the factory wheels?

Assuming the Toyota systems operate like Chrysler/Honda/Audi ones, you will just have the tire warning lights displayed on the dash the whole time. Some cars have 2 lights (one for low pressure, one for system fault) so you may get to double your fun. Hopefully somebody can chime in as to if that system is self learning or not. Worst case, you may have to take it to the dealer or competent independent to have the sensors registered to the module when you reinstall. Best case, you do nothing and it learns them.

logdog's right. The later Chrysler systems will flash the light and sound a chime if it doesn't detect a sensor or sensors. That can be aggravating as hell on a long trip.

If they are the wireless kind - install all of them on the spare and never worry about it again.

If it's just for snow tires then skip them and try to ignore the TPMS warning lights. Alternatively you can put them in a pressurized container and keep it in the car but they should be mounted inside the container in a certain direction and then mount the container in the car so that the sensors are aligned longitudinally with the vehicle - normally they charge like a shake light and get a little boost every time you go from acceleration to deceleration or back. This charging also wakes them from sleep mode when the vehicle moves off after being parked for a while, so by mounting the sensors this way you'll get the same behavior.

Throw your spare tire on and see what lights illuminate, making sure you can live with it.

I've run without them on our RAV4. You get an annoying glowing light on the dash, but there are ways of eliminating that, as well:

http://www.rav4world.com/forums/98-4-3-interior/85538-how-disable-tpms-how-turn-off-tpms-light.html

Since Toyota designed the interior, I wonder if they used the Toyota system or the Subie system on the FR-S?

If the TPMS sensors had better longevity, I'd consider replacing them when they go. As it is, I check tire pressures regularly, so I'm not too worried about not having them. I had one snap off while I was filling the spare (never had that happen before), and the valve on another developed a leak that led to a flat. The valve stem and TPMS are integrated, so if either one fails, you're stuck buying the new part. Two out of five valve stem/TPMS sensors failing in 6 years does not impress me. The sensors are not cheap, and I hate the idea of paying labor to have them reprogrammed each time. Basically, I can get a set of four new tires for what it would cost me to replace the two broken sensors with the programming.

dj06482 wrote: I had one snap off while I was filling the spare (never had that happen before), and another sensor developed a leak that led to a flat.

The sensor itself can't cause a leak, it just hangs on to the inside of the valve.

Hey just ran across this, aftermarket programmable TPMS sensors that can use the same IDs as your current ones, so you can just swap wheels

http://www.subaruoutback.org/forums/81-wheels-tires-brakes-suspension/39671-subaru-tpms-cloning-orange-electronics-sensors.html:

I run snow tires without the sensor on my RX-8. I get an orange light. I cover it with tape.

GameboyRMH wrote: The sensor itself can't cause a leak, it just hangs on to the inside of the valve.

You're correct, but the challenge is that the valve stem and TPMS are integrated into one part. So, if the valve fails, the whole thing needs to be replaced. I'd be much more interested in a set where you can replace only the valve stems with tire replacements, as the TPMS sensor itself should last longer than the valve stem (and is far more costly than just the valve stem).

dj06482 wrote:

GameboyRMH wrote: The sensor itself can't cause a leak, it just hangs on to the inside of the valve.

You're correct, but the challenge is that the valve stem and TPMS are integrated into one part. So, if the valve fails, the whole thing needs to be replaced. I'd be much more interested in a set where you can replace only the valve stems with tire replacements, as the TPMS sensor itself should last longer than the valve stem (and contributes to most of the cost).

Aren't the sensors held onto the bottom of the TPMS-compatible valve with a tiny nut? Or at least you can definitely buy that type...

What everyone else said. We do this every winter on my wife's Taurus. Just a slightly annoying light to deal with, no other problems.

GameboyRMH wrote: Aren't the sensors held onto the bottom of the TPMS-compatible valve with a tiny nut? Or at least you can definitely buy that type...

I haven't seen the sensor first-hand, but there are several decent pictures floating around on the web:

Sure there's not a nut or screw in that slot facing away from the end of the valve?

Like everyone else, I ran my snows without sensors. Light gets easy to ignore after awhile.

I had a shop reprogram the computer so the car can live without them.

i just want to weld a little stainless box and put them in it and pressurize it and bolt it under the hood somewhere...

I thought about the pressurized can, but my research indicates that they detect wheel rotation. The can would have to spin.

If there is some kind of deranged noise that goes on for even a minute or more before going quiet, I will go nuts.

Is the receiver integrated into the main computer or is it a module under the dash that can be hacked?

NOHOME wrote: At $300 to have them installed, I am inclined to skip the TPS when I buy the snow tire/rim package for the FRS. Anyone else drive without them and is there anything I should be aware of if I do this?

We've run without TPMS sensors in our Odyssey's snow tires/wheels. We get a "TPMS" light on the dash all winter. When I swap back to summer wheels/tires, the sensors wake up and the system works without any programming or user intervention.

One strange thing about the Honda system (maybe others, too) is that you cannot turn off traction/stability control when the TPMS warning is active. The button on the dash to turn off VSA does not function. If you ever need to turn off traction control in the winter to extract yourself from a snow bank or burn through some ice, you won't be able to do this--unless you find the fuse under the hood.

I would not be surprised if the TPMS system is separate from the main computer. You know how the US mandates everything and it probably isn't required elsewhere......

I have heard on some hyundai's, if you unplug the TPMS module the lights go away. YMMV

GameboyRMH wrote: Sure there's not a nut or screw in that slot facing away from the end of the valve?

some chevys are like that, I havent seen any others like that though.
Some fords have a band around the wheel, sensor is 180* opposite valve stem. MOST have the metal valve stems though, all one piece with a nut holding the vs/sensor to the wheel
All nissans, all korean cars, all subies and toyotas I've worked on have had the metal kind.

Ready? Here's how you do it.

Get a piece of pipe. Drill a hole in it for a valve stem. Place all four TPMS sensors in the pipe and seal it at both ends. Use the valve stem to "inflate" the pipe to 36 psi. Put the pipe in your spare tire well.

Done. Now you can switch wheels and tires to your heart's content.

NOHOME wrote: At $300 to have them installed, I am inclined to skip the TPS when I buy the snow tire/rim package for the FRS. Anyone else drive without them and is there anything I should be aware of if I do this? Also, if anyone knows of a steel wheel that will fit this car, I would love to know; Tire Rack does not carry a steel rim for the FRS and Scion wants more for a steel wheel than Tire Rack does for an alloy.

For the FR-S, if you run a set of wheels without TPMS sensors then TPMS light will begin blinking for a little bit after 20-21 miles of driving then remain lit. There is no beep or chime, just the dash light. If the TPMS does come on from exceeding the 20-21 mile one way range, it will go back off after spending the night in the garage with the factory wheels. So If you keep the factory wheels in the garage by the car and drive less than 20 miles one way then you will never see the TPMS light come on.

Also, thankfully, the TPMS light being on has no effect on traction/stability system fuction - so its still capable of everything from full on to completely off.