what is wrong with this TPMS?

All my tires are fine but it keep on saying I got flat on my left rear... Turn the car off and restarted and the warning comes out again... I heard that couple ppl had the same problem but this TPMS is not good.. I'm going to visit dealer tomorrow morning...

Sounds like a bad sensor, much more likely than a problem with the receiver or computer. Agree you should have it checked out. The more common complaint is the pressures reading lower on the TPMS than on gauges, a result of the TPMS only being able to sense pressure inside the tire, where the gauge compares it to the ambient pressure outside the tire. Greg

today i checked car again and there was a little nail... TMPS has no problem!! lol

Damn those Germans and their crafty engineering! I have a non- TPMS '06. I thought I was glad not to have it. Heard about issues with false alarms and warning lights driving you crazy. Now it sounds kind of valuable No matter what I'll get it on the next one -- no choice.

I have had plenty of TPMS demons in the past few months but they seem to have gone to sleep for now. The readings are of course no where near accurate. I check my pressure almost daily with a racing gauge, TPMS reads about 10 lbs less in the front tires than actual and about -7to -9 in the rears. At least it is consistantly wrong.

Is there a calibration function that you can perform or do you have to take it to the dealer to have fixed?

I've had the same problem with the indicator for the rear tires . They're on spec,but indicator shows one to be low. Add air to 40 PSI & bleed the tire down to spec or a pound over. This worked for me.

I recalibrate quite often and the readings always come up the same or close to them. I was having a problem where the rears would show a flat (left or right depending on it's mood) but that has stabilized for now.

Tpms Mine did the same **** yesterday. I added air and still could not clear message. After checking an old post from Sante Fe I went into the menu and re entered the tire size and type-winter/summer. There was a message indicating LEARNING. it lasted about 10 minutes and then cleared the error message and read the appoximate pressure. ( Not totally accurate acording to my 50.00 gauge from hutcherson pagan.) In any case I am convinced that this is the way to clear the error message. The dumbass local dealer said that I would need to bring the car in to reset the computer. The long term expets on this board know more than the dealers.

I've had at least three occasions were the warning comes up but all it says is that the system is relearning. Only 1000+ miles so far, hmmmm? It takes some time usually but comes back to normal readings all around. Might try the suggestion to over inflate and reset to recommended pressures next time and see if that changes anything.

Jerry, I'd have this checked. I have 22600 mile on mine and this has never happened to me unless I manually reset it (when changing to track wheels) Greg

tpms Other than letting you know if you pick up a nail- I have found the TPMS to very inaccurate and problematic. As a result of this-I bought a intercomp 0-60 lb 3.5" diameter racing grade tire pressure gauge. glows in the dark. also has a neat air release valve button. 44.00 at a local NASCAR supply house. GREAT PRODUCT!!!!!!! TPMS readings never match even with cold tires. I have had to go back twice and reset the TPMS alarm by choosing a tyre size and having the unit re-learn which clears the error message.

Porsche uses a "direct measurement system" made by Beru which has a pressure sensor in each tire which broadcast a signal to an antenna mounted in each wheel well that is further transmitted to a central processor. This has been found to be superior to the less expensive "indirect measurement system" that uses the relative speeds of each tire as calcuated from the ABS system. For more see http://www.beru.com/download/produkt...pekt_tss_e.pdf The system itself never really knows what the actual "relative" pressure is - meaning, the differential between outside (ambient) temperature, and pressure inside the tire. The sensor is only INSIDE the tire. When you check the tire pressure the old-fashioned way, with a gauge on the valve stem, you are reading relative pressure - the differential between the pressure in the tire and the pressure outside the tire. The gauge reads zero before you put it on the tire, it does not read 13.5 PSI, which is the absolute air pressure of the atmosphere surrounding the tire. TPMS is a warning system that can save tires, wheels and lives however tires should be routinely checked while cold with a tire pressure guage like the Intercomp or other reliable guage.

Interesting. Never knew that. When i got my CS i tossed all my cheap air gauges and put the good one back in the tool box as i thought that TPMS eliminated the need for a tire gauge.I would bet a lot of other new 07 CS owners thought the same thing. Live and learn.

Other fun facts about TPMS ... It also attempts to compensate for temperature, meaning that it EXPECTS higher pressure when the temperature rises. I've received low pressure warnings when bright sun light has warmed up the wheel where the tire value is, but the entire tire (and air within) were not as hot - consequently the pressure had not increased as much as TPMS expected and a warning was issued. Worst of all, since TPMS measures absolute vs. gauge (aka relative) air pressure in the tire, it has to GUESS what the absolute ambient air pressure is. On the Colorado front range at 5000ft altitude, the absolute ambient air pressure is about 85% of that at sea level. This means that there is around 2PSI error in the TPMS (reading low vs actual gauge pressure). This combined with imperfect temperature compensation is why I get errors so often. I trust my Longacre racing gauge and the TPMS says I've got the pressures too low! What do the (uneducated, naive) dealer technicians tell me? "Never use a gauge, always put air in until the TPMS reads the right value." Sorry morons - I'm not going to drive around on over-inflated tires ! If this system were designed correctly, there would be a fifth TPMS sensor which reads the ambient air pressure and ignores temperature. The system should then subtract the ambient pressure reading from reading from inside each tire to decide whether or not there is a problem. Bottom line - if you live at altitude and don't want TPMS warnings on a regular basis, run your pressures slightly high. Someday I'll find someone at Porsche who is willing to talk about the flaws in their design and how to improve it.

I had a -4 left front warning. Checked the tires , it read 31.5. I then realized that this was not a cold reading. Waited until morning, rechecked and the reading then was 28.5. Close to four pounds down. Added air until 32 psi but the error message continued....until the tires warmed up at about 3-4 miles then warning was gone. Ken