Tire pressure sensors - Question
 

I purchased four wheels and snow tires for my RX8 and expect to have them put on tomorrow. Do I have to install the tire pressure monitoring sensors on these wheels also or can I run the new wheels and snow tires without them?

It's my understanding that if I want to use the current pressure monitors on the new wheels I would have to remove the current tires from the wheels to get to the monitors. Obviously I would rather not do this so there seem to be two alternatives:

1) Buy new monitors for the snow tires, but I understand the cost is about $160 ($40 each).
or
2) Not use the pressure monitors on the snow tires. I think this might cause a light to go on in the dash (which I can live with) but not sure if there are any other warnings (maybe a buzzer or bell constantly sounding, which I couldn't live with).

Any advice would be greatly appreciated.

I switched to snow tires on mine. Someone said somewhere that there was a 3 second beep when the light turns on but I have yet to hear it. Maybe I'm revving the car too loud :) *it's probably my stereo* and the blinking light isn't really distracting at all. I will however be excited for warm weather so I can play with my performance tires once again. Although, taking sliding turns on snow = FUN!

TPMS Sensors run more like $80 to $100 per tire. You probably don't want to unmount your stock tires to get at the sensors if you already have the snows on different rims. The concensus is that the light on the dash blinks and that is about it if you don't have the sensors installed. Search on SNOWS or TPMS to read more.

Hope this helps. :cool:

It is only a small flashing yellow light no beep. If you are interested in the sensors I believe that they are around $80/tire. Don't take them off the other wheels or you will have to pay to have the wheels remounted and balanced. If you are going to have them installed it would pay off in the long run to just buy the sensors IMHO.

And yes it is fun to disengage the DSC and just whip the car around in the snow :p.

I have a spare (no tire sensor) on right now and it beeps like mad when you first turn the car on, and the yellow indicator remains lit. Maybe if it gets no signal from any of the wheels it just ignores the warning but will show it if it receive signals from some, but not all of the wheels(?).

If all four TPMS sensors are present, and one or more tires is outside the acceptable pressure range, then the TPMS system lights the yellow warning light constantly, accompanied by a single long beep. This indicates that the system is working and has detected a problem.

Conversely, if one or more of the TPMS sensors is missing or not functioning (because it's broken, or lying in the trunk because you've fitted the spare, or because you've installed wheels without TPMS sensors), then the system flashes the TPMS light constantly to indicate that there is some sort of problem with the TPMS system itself.

So: constant light + beep = system working, problem with pressure; blinking light = system problem.

Hope that clarifies things (though I'm sure this will come up again and again because nobody seems to use the search function).

Please clarify.....I was under the impression that the tire pressure yellow light went on when one of the four tire pressure was out of synch with the other three. that is what I thought "alerted" yellow warning light to go on. This evening went I left work ( outside cold spell) yellow light went on. After about 5 minutes of driving, it went off. Later that evening after car was sitting in garage I checked all four tires and they were all at 32 psi. Because it was very cold outside I know I lost "equal pressure" in each tire. So I guess I was wrong with my one tire out of synch theory.

No, the light will come on if one or more tires have too little (or too much) pressure. The system monitors the absolute pressure in each wheel, not the pressure differential between wheels. One or more of your tires must have dropped below threshold while sitting in the cold all day. Put an extra couple of pounds in each tire and you should be good all winter.

harwax,
Ecles explained the bit about the light.

About your tire pressure: Do you have snow tires? If so, you should inflate them to 36 psi cold (32 psi cold for stock summer tires). Cold means the tires are at cold outside temperature, not garage temperature and not after you've been driving on them and they're still warm.

If your garage is 20 degrees warmer than the outside temperature (and your car has been parked in the garage for hours so the tires are garage temperature), add 2 psi (1 psi per 10 degrees difference between garage and cold outside temperature) to your target pressure - so for snow tires they should read 38 psi in this example if you check them in your garage.

Just curious, how long was the car in the garage when you check the temperature and read 32 psi?

regards,
rx8cited

When I first installed my winter tires and rims, there would be no light until I had driven for about 10 minutes, then the light would blink until I shut the car off. This pattern has repeated itself many many times. Now all of a sudden (I think it started last Monday), the light stays on constant from the time I start the car until I shut it off. Anyone know what's going on here? My summer tires are mounted on my garage wall, so the car is in close proximity to the sensors some times if that matters.

Thanks, all, for the information on the tire pressure sensors. I'm going to have the snows installed today (225 - 50R-17 Bridgestone Blizzaks with Kazera KZ-R 17x7 alloy wheels). At about $80 each for the monitors, I think I can live with the blinking dash light for a few months a year. My concern was a constant alarm type sound which, based on the experiences of others, I assume will not happen.

rx8cited

My car was sitting in garage about 5 hrs. I got home at 6 pm and checked tire pressure aroung 11 pm. I have original tires. I added about 3 lbs (to 35psi) and so far no repeat of "yellow light".

Harwax

Not for me.

I had a set of Blizzaks put on the stock rims.

NO TPMS lights till I warm up my tires.... usually takes about 30-40 minutes of around town driving or about 10 mins of highway speeds before my light starts to flash.... and if I pull over into a rest area and let the car sit (with car still running), the light will eventually stop flashing.... till I get them suckers warmed up again.

So based on your statement... blinking light = system problem, means I have to warm up the tires before I get a system problem. I have never seen a constant light and have never heard a beep. I'm confused... my tire pressures are set at 36psi all around. :eek:

That behaviour is not normal if your pressures are indeed 36 warm. A blinking light most certainly does indicate a system fault. I'd be tempted to have a dealership check your TPMS system, because it sounds to me as though one of the sensors may have been damaged during the tire swap.

i changed mine today...took me an hour by myself...anyway no TPMS sensor after installation which i also posted in Tech Garage...i drove for about 15 minutes afterwards and no lights at all...i'm guessing maybe they didn't warm up enough for the sensors to trip as previously stated...will report back in tomorrow

Hi Wankeler,

I hope I'm wrong, but I'm guessing you have one or more broken sensors after the tire swap.

I'm guessing that when you pull over into a rest area, the TPMS realizes the car is not moving and stops looking for a signal from the sensors, so the light stops flashing. Then once you get going again, the TPMS starts looking for signals from the four sensors and does not receive all four signals, so it starts flashing the yellow TPMS light.

regards,
rx8cited

My thoughts precisely. Though hopefully it's not the case, in which case I'd love to hear what is causing it.