I am new to this forum and have found the site extremely informative. A few weeks back just after I had purchased the car I had a nail in my rear passenger tire, I took it to a tire shop around where I live and the tire was patched and then plugged after the guy said the patch wasn't taking. The tire has been fine so far.
My question, later I learned that my Crossfire had a tire pressure monitor system, I am not sure if the guy put the TPM system back into place as he had to take the tire off the rim in order to patch/plug the tire? Is there anyway I can check to make sure it is back in place, short of taking it back to the dealership? Thanks, any input will be helpful.

 

It seems to me that the easy way to check is to take the car to where you have immediate access to an air pump and let some air out of the worrisome tire. If the TPM indicator light doesn't come on, you have your answer. And if it does come on, you can rest assured your system is operational.

By the way, welcome!

 

If you don't have the TPM in your tire the low tire pressure icon will show up.

My next question will be: Does the computer compensate with the speed whenever your TPM appears?

I have my wheels changed and I haven't transferred the TPM yet with my new wheels. I was just wondering if it'll ruin the computer system if I keep it appearing in my dash!

 

Ok, thanks for the responses, I was going to let some air out of my back passenger tire and then check to see if the tpm would come on inside the car dash. But you’re saying that the tpm icon inside the car dash would come on if it was not in place?
I am a little concerned because I am getting ready to take a road trip and am a little paranoid about getting a flat, because I really don't want to mess with that.

 

The TPMS will only tell that you have a pressure loss of at least 25%, this could be one tire or a combination of tires. If you have a Limited or SRT and the TPMS unit was left out of your tire your TPMS light should be on, the Base XFire's do not have the TPMS.

 

Ok, that makes sense, I have a limited 2005 crossfire, I will assume the TPM unit was put back into place since there is no TPM warning light going off on my dash. Thanks for the input.

 

If the pressure icon does not showup on your instrument pannel I would consider everything is ok.

 

This has been discussed many times before. TPM doesn't calculate pressure across all four tires. If any individual sensor registers a pressure loss, it sends a signal to illuminate the dashboard light. Here's the quote from the service manual:

Note: The "low" pressure threshold is defined as 26 psi. I couldn't find a reference for "critical" pressure.

DESCRIPTION
This vehicle has a tire pressure monitoring (TPM) system. It is there to alert the driver when air pressure in any of the vehicle’s four tires falls below a predetermined threshold. It alerts the driver with a lamp in the instrument cluster.

The tire pressure monitoring system utilizes transmitters that are located in the valve stem of each tire to communicate the tire pressure condition to the module. If a tire has low air pressure, an indicator light on the instrument cluster is illuminated. The vehicle operator must check the tire pressure of each tire in order to determine which tire has a low pressure condition.


The garage door opener/tire pressure monitoring (TPM) module has a microprocessor controller that can monitor the transmissions from the sensor/transmitters anytime the ignition is on. It can store the last 32 transmissions. There are two important values included in these transmissions. They are:

² Why the transmission was sent,
² Low Tire Pressure

The module compares the transmitted tire pressure from the sensor to the two pressure thresholds (low pressure or critical pressure). If the module determines that the tire pressure transmitted is below the low or critical pressure thresholds, it will signal for the “Low Tire” pressure warning lamp to come on.

 

I'm just curious about Cyrill's question. I have a set of rims and tires already from my old SLK that I'd like to move to the Crossfire; and I'd like to avoid the expense of breaking apart two sets of wheels just to get the pressure sensors. So if I mount the wheels without the sensors, is the light on the dash board the only thing I have to worry about? or will the computer actually intervene by changing the speed limiter/abs/traction control?

 

Checking to see if the tech reinstalled your tpm is a snap!! Look at your valve stem in the wheels. If the valve stem is a bolt in (it is silver and has a nut holding it in) then you are golden!! If the valve stem is black rubber your tire tech did not do his job, return to him & tell him you want your sensor installed. Retail on one of those is about $55.

 

You can purchase metal valve stems at any auto parts store or tire shop so that is NO indication that the sensors are there.

 

This is an old thread, and I had my TPM show up for the first time today. It coincided with the temps dropping by 20 degrees or so, though I keep my car in the garage. I will check the tire pressure today, but should I adjust for the cooler/colder temps? In Seattle we don't get extremes in cold or hot, but right now, the temps are low: 30's ...too high...mid to upper 40's-50s.

Thanks!
GG

 

This has been a problem for me with my car from the start. It's interesting that someone says in this thread that the level where the light is supposed to turn on is 26 psi. Mine seems to be anything under 32 psi.

I've not been able to go for more than a couple of months without the tire pressure light coming on. Every time I take the car to the dealership for 3k mile service, they without fail set the tire pressure to about 33 psi, which makes the light come on the next morning.

Now I have to replace my rear tires after 11k miles, and this situation leaves me not knowing if this may be due to too high pressure or too low pressure. Or did I just have sucky tires (or blowy)?

I've heard that 36 psi is the "correct" cold pressure. Is this right or wrong?

 

Stacy, you should probably double-check them whenever there is a drastic change one way or the other. Cold pressure (before the car has been driven) can vary 1 psi for every 10 degrees of temp change.

 

How was the tread wear? More wear in the middle would indicate over-inflation, more wear on the inner and outer edges would indicate under-inflation. I run the recommended pressure indicated on the door jam sticker and periodically check tread wear with a gauge and it seems to be even all around...so far with nearly 10,000 miles.

 

Any time there is a wide fluctuation in temperature it is a good idea to check your air pressure. The only down side is in some parts of the country it can be 30 degrees in the morning and 70 degrees in the afternoon. That can be cause your air pressure to change enough to trigger the tpms light. I would recommend switching to nitrogen and that will cure your fluctuation problems. Going price here in Atlanta, Ga is $30 - $40. Lots of dealerships (mostly high end, benz, lexus etc.) have already upgraded equipment to convert to nitrogen because of C.S.I. complaints. If you have nitrogen in your tires & your tpms light comes on, bottom line, you have a problem!!

 

It looks to my inexperienced eye that the wear is more to the outside of the tire. That may just be due to being able to see that part better. I'm going to have the installer for the new tires give me their opinion on the cause of the early wear-out.

I looked at the pressure recommendation on the door, and it says 32 front, 33 back, cold. That's what I've been going by. Could my problem be that I'm always setting the pressure in the middle of the day, so that I'm somewhere in the "warm" to "hot" range, resulting in under inflation?

Do people target 36 psi because when you fill the tires it's typically during the "warm" part of the cycle?

 

The "cold" inflation temperature doesn't mean you should set your tires to that pressure when it is cold outside. It means that your tires are not hot from driving, so you should inflate your tires to the "cold" pressure when your car has been sitting for a while so the tires have had a chance to cool down from their operating temperature.

 

Understood, but considering that my low pressure light always comes on when the temperature drops, whether the tire is "hot" or "cold" is obviously a combination of friction with the road as well as ambient temperature. Actually, once the light comes on it doesn't usually turn back off until the ambient temperature increases. That's given that I don't usually drive more than about 10 city miles at a time.

I've never struggled with this in the past, but the Crossfire has been a pain in this department. I owned '97 and '99 Vettes, and the DIC would tell you the actual pressure in the tires. Low-profile tires do seem to be more sensitive to temperature changes, because I needed to put air in the Vette EMTs from time to time. However, the Crossfire is much worse. Every time I set the pressure high enough so that the warning light turns off, it comes back on without fail in a month or so.

For example, when I take the car to the dealer, the low pressure light ALWAYS comes on the next morning. Even though the dealer seems to give the same treatment to a Crossfire that they would give to a Grand Cherokee, I would think they have some clue as to the proper tire inflation procedure. I've been miffed that it seems the pressure sensors for my car are set to go off just below the suggested inflation pressure. It's either that or I have bad tires I guess.

 

I check mine every couple of weeks and have to adjust 1-2 pounds consistently, as all tires will seep air. The best suggestion so far is to replace the air with nitrogen, but that will cost you a few bucks.

But...I have one more (maybe ridiculous) question. Do you have a good/accurate tire gauge that you are using? Those .99 specials or the built in ones on the air hoses at gas stations can be off by more than 5 psi. If not, you may want to check into something like this: http://valvelock.net/shop/index.cgi

By using a good gauge and checking every few weeks, I have never had a TPM light in the year and a half I've owned the car.