the past few days, whenever i fire up the car (the 997), it always tells me that the front left and right, along with the rear right tires have lost 4 psi. the very first time this happened, i check the pressure of all 4 tires and everything was fine so i just reset it, drove it around for awhile (so it would re-calibrate) and the warning went away.

now i always have to reset the monitoring system before i drive so i dont have to drive with some stupid red exclamation mark. to top it off, right after i turn off the car it shows there is lost pressure on the tires again. it is always random and says its those 3 tire or just 1 tire, maybe even if im lucky, all 4.

do i just have bad sensors or what? any ideas?

 

had the same thing happen to a customers IS350 w/ 20" hre's, swapped out sensors to no avail. Wound up taking a 4in. dia. pvc sealing the tpms sensors inside and filled to 40psi. Took care it, tpms = bullshi$ in my mind. Good luck.

Phil

 

Could it have anything to do w/ cold vs warm tire pressure? I notice my tire pressure is at least 4-5 psi less when I first start off then when I drive for a while, it's still cold here in NY 30-50 degrees.

I didnt realize how much I would use the TPMS. I changed out my wheels so call me paranoid but I glance at it at least every 5-10 minutes. It's really a great thing to have w/ very low sidewall tires. Hope you get it sorted out.

 

thanks guys.

forgot to mention that i am still on the stock tires + wheels.

 

Started to drive away from dealer the other day and this same exact thing started with my 07' 997.1. It was late in day and figured I'd add air later but tire was fine. two days later and with correct tire pressures, I'm still getting this stupid warning (-4, in left rear)! I haven't tried resetting TPMS (as I haven't figured out yet how to). Just wondering what the fix for you?

 

Had the same problem on mine with brand new tires and wheels with new tpms sensors. The issue was in the part that reads the data from the sensors. Dealer said they have issues with them and they just replace this part. Problem no more. Most likely your tpms sensors are fine and the problem is in the cars reading part. Sorry don't have the name for the part but the dealer knows the fix.
Js

 

See post #13 here http://forums.rennlist.com/rennforum...7294-tpms.html and seems to have worked!

 

Similar problem. Dealer here says it's sensor. Confirmed last week it's not the sensor. Now they think it's the "antenna". It's on order. We'll see.

 

??? did they mean the TPM "receiver"? (module receiving signal from sensors in wheels.)

 

I guess that's what they meant and I hope that's the solution. I can't stand Christmas lights in my car.

 

Wanted to see if those of you that had the TPMS "receiver" replaced had the problem go away. Just the past week mine is acting up. Every time I start the car it shows TPMS system inactive and/or low tire pressure (-4 or -5) for all four tires. But when it displays this there are no pressures displayed on the tire psi diagram. After resetting the TPMS through the left stalk and driving for 15 or so minutes, the light goes away and the tire pressures are FINALLY displayed (appear normal). But as soon as the car is turned off I have to go to the same process. I hope this is covered by my CPO warranty...

 

This will happen around this time of year as temperatures fluctuate. Make sure you're at the correct cold (Car has been sitting for 3-4 hours) inflation pressures and don't sweat it.

If the problem persists into the 50-80 degrees F range then worry about it.

 

Not much fluctuation here as of yet. Low's in the upper 60's, high's in the upper 90's. No different from when before the issue started.

 

What pressure is everyone running? I'm 31 in the front and 37 in the rear. I never got a TPMS light at these pressures before, but all of a sudden car is telling me I'm low.

 

I have to do 34 and 40 otherwise I get the idiot light everyother day. Stock rims and tires.