My instrument panel is showing the "low pressure" icon for the wheels. I checked the pressure yesterday and got 33psi in the rear and 32psi in the front. Is this a faulty sensor? Can this be cleared using an OBD tool assuming a code has been set?
TIA

 

There is no code to reset. The TPMS just looks at the signal and if one of them shows more than x% difference, it sets the dash display. When the air is re-balanced the display will go out shortly afterwards. Mine will go on on very cold mornings and then go out after the tires warm up. Try setting the air the same in all wheels and see if it will clear. It SHOULD take at least a 3 or 4 pound difference to set the display.

 

I have no expierence on the Crossfire yet, but on Ford you have to drive the car 20 mph before the light will cancel after you correct the tire pressure. The sensors only transmit a signal over 20 mph to save on battery life when the car is sitting still.

James

 

As James says, have you driven the car since filling? If not, you need to.

I know someone that has the same problem. One of his TPMS sensors went bad. There is no simple way to find out which sensor it is.

 

If you do have a transmitter (sensor) problem, you need a DRB3 tool and a calibration magnet tool to figure it out. Unfortunately for me that would be "dealer time" since I don't own either of the tools.

James

 

All good points, but did you check your tire pressure when the tires were hot? The sensor will alert you if the tires are off by 10%. So if you checked them when the tires were hot, that might be your difference. Make sure you check then when they are cold.

 

 

I can tell you that my indicator will come on right after winter storage. When I check the pressure it's at about 30 lbs. Once I inflate them properly, the indicator goes.

 

Quote:

All good points, but did you check your tire pressure when the tires were hot? The sensor will alert you if the tires are off by 10%. So if you checked them when the tires were hot, that might be your difference. Make sure you check then when they are cold.

Yes the pressure was checked when cold. The sensors are supposed to activate a warning when pressure drops 25%. At 33psi, that is 26psi. Knowing that pressure increases and descreases as temperatures change, a 25% difference is a lot. My point being that unless you ignore your pressure and let your tires drop to 26psi, you should never see that warning icon. I'm guessing one of the sensors is faulty.
FWIW, the wheels are filled with Nitrogen with a 2yr warrenty against leaks.

 

My sensor light has been on so long I don't even notice it anymore. I would like to get it to go out, but I probably have a bad sensor. I guess I will have to go to a dealer and see if they will scan them for me to find the faulty one. so these report on pressure and not on revolution difference? I used to wonder if the light was because I was running 18 inch wheels but my tire diameter was the same as stock with 225 40 18 and 255 40 18 and the light would not go out. I am now running a slightly wider and taller tire than stock in the rear which are 265 40 18.

 

I may be way off base here, but what is the expected battery life of the sensors?
If the car in question is an 04, it could be close to 5 years old now.
I'm just speculating.

 

This is my first car with pressure sensors and from what I have heard
from friends, colleages and others, they can be annoying. For example,
during the winter months as tires cool and then heat up, the warning
signal will come on a lot. My boss drives a new Honda CRV with wheel sensors.
His idiot light is always going off and on, even with the pressure checked and OK.
If you want the warning icon to go out, just remove the bulb. Something I am
already thinking about!

 

Good point, and one I have thought about. These sensors are new to me so I ask; are they sold as part of the rim or are they sold seperately and then installed at time of tire mounting? Anybody know how long they transmit for (battery)?

 

Mine is a 2004 and I think I heard five years is how long they last.

 

My light has lit up with no where near 25% drop in pressure. I have had it on with a difference of only 4 or 5 pounds. I top the offending tire off and it goes out shortly after that. Of course I have been driving or just getting ready to go out when I did this, so I got over 20mph soon after adding air.

 

FYI - The service manual states that if you get a DTC (Diagnostic Trouble Code) for a transmitter low battery, the sensor must be replaced. Says nothing about changing out batteries.

James

 

I guess one of the benefits of the new advertising on the forum is you get adds at the top of the screen that pertain to the the topic of the thread.

Here's a link for buying new sensors:

Click here

 

From the on-line service manual...

 

Battery life is expected to be 7 to 10 years, that is what the industry standard is. The units are installed like a regular valve before the tire is installed.
Was anything done prior to the light coming on? If you have had tires fitted and the light came on at that time I would suspect that a unit was damaged during the installation of one of the tires.
How these things work is a mystery to me, I know they transmit a signal and are tied into the garage door opener transmitter.
I am puzzled by the two year warranty against leaks after a nitrogen fill, does that mean you are not going to have to put air into them for two years, I somehow doubt that. I had nitrogen and I saw no difference with it, although some people I spoke to about it thought is was the next best thing to sliced bread.

 

Molicules in Nitrogen are larger, causing less slow leaks... so I am told...

James