My TPMS intermittently fails and then comes back on-line within a few miles. My local technician checked the TPMS sensors through the OBDII, and they all work and have good batteries. Since it's a total system fail and not just one or two sensors not registering pressures, I am deducing that the main module may be going out or that I have a loose connection or short in the harness or connector. However, if any of you guys have other ideas I haven't considered, I'd welcome your input.

Thanks!

 

I had the dealership disable my TPMS, just too many hassles! Batteries going flat, swapping wheels was a pain, screw it I can use a tire guage, imagine that!

 

You cannot use a tire gauge while driving down the highway at 70+ MPH.

 

ya mine keep f,?!'i up. just replaced them. I'm going to disable them. dash keeps blinking

 

It's a nice to have but when they start to go bad after 5 years, you either need to dismount the tire/wheel and replace the TPMS or replace everytime you do tire changes. Then you get the occasion when even after that the TPMS won't read/register. In the end and beyond frustrated I said I'll read the tire pressure manually at rest. If money & time are no problem sure it's cool to measure the tire pressure at 70, although I suspect you'd know if one of the four was significantly lower just by the driving characteristics. It cost a couple hundred to disable the master TPMS unit in the frunk and I couldn't be happier, no red ! on the dash and 'no when will this thing register'.

Can you tell it's a topic that gets my goat up?

 

yes I agree. big **** off.

 

It may not be anything to worry about. My '09 does it occasionally--mostly for the first few days after I swap wheels.

There's no rhyme or reason to it with my car. Sometimes its one sensor, sometimes two, sometimes all. Telling the PCM to re-learn the sensors clears it after a few hundred feet and after two or three times, it goes away--until I swap wheels again.

It does it with the Porsche TPMS AND with the aftermarket TPMS. I have learned to live with my car's foibles.

 

I am in the same boat with my 07tt. I had in the dealer multiple times with no fix under CPO. They even replace all the wheel sensors and check the antennas at each wheel. Now that I am out of CPO I am just living with it every few months. Seems the change in the seasons seem to be a trigger. I loose all wheels and not just one or two when mine goes out. I might try replacing the TPMS controller this fall. It is only a couple on hundred bucks and a few hours to replace.

 

This doesn't appear to be a TPMS wheel sensor or antenna failure at all. I've ordered a primary module (located on the left side of the car under the plastic in the frunk) and will let you all know if replacing that module fixes the problem.

 

JB, that would be awesome. A brief write up would be helpful too. It doesn't look to hard from the parts pictures. The dealer I talked with about it said it was a plug an play replacement too. So you don't have to get anything programed.

 

Well, replacing the "mother" module" did not solve the problem. The TPMS is in a permanent learning mode. I have an aftermarket warranty on the car, so I called the dealer I bought it from, and they have authorized me to have it repaired under warranty as long as it doesn't turn out to be the wheel sensors - which are excluded under the terms. However, if it DOES turn out to be the wheel sensors, then I would have had to pay to have them replaced, anyway. The OBDII shows I still have a couple of years left on the batteries in the sensors, so we'll see.

Replacing the mother module was easy and the only tools needed were a Phillips screwdriver for taking out the retaining screws for the plastic closeout in the frunk, and a 10mm socket and 1/4" driver for removing the plastic nut that holds the module in place. Replacement is a <15 minute job. If the module is disconnected, you may get a "PSM Inactive" fault warning when you restart the car. The PSM will reset and this warning will go away after a few minutes, so don't worry about it.

Regarding someone suggesting that I disable the system, it's my preference to keep things maintained and functional, or I will take perhaps an even bigger hit on valuation when I sell or trade in the car if something isn't working right.

 

My god, what did people do in the dark days before 2007? Did everybody die from not knowing they had flat tires?

 

Have you gone through the on board computer menu and re-set/update the wheel/tire settings? I put a different set of wheels/tires/TPMS on my car. I drove for a few miles and the indicator showed -- for each wheel while it was re-learning my new combo. After a while it showed the individual tire pressures. Later the display actually asked me if I changed wheels/tires. I had to stop the car and go through each step in the menu.
Tire size?, winter or summer?, half load or full load? After updating everything, it went through the entire learning process again and when finished everything work perfectly after that.

 

So true. Also what did they do before ABS, Stability Management, Traction Control, and auto trannies.

 

The feel of a flat tire is unmistakable; if you're in-tune with your car and a tire goes flat as you're driving, you're going to immediately notice it and don't need a computer to tell you to pull over. One problem we do have that's particular to our sorts of cars is that low-profile tires with very stiff sidewalls (like most Porsche performance summer tires) are not always 100% obvious by sight or by feel when they're approaching dangerously low pressures. So, it's often difficult to tell you have a flat before you hop in and drive away, but only because the sidewall does almost as good a job of a run-flat at protecting the rim from damage. You'd notice it pretty quickly after that, though.

On a related note, I got a set of MPS on 19" wheels with a car I'd recently bought; the prior owner had apparently hit a few potholes. The wheels were fine, but the tires had been damaged; subtle on one wheel, not so much on the other, and easy to recognize (which is why I drove the car home on snow tires in June). I cleaned the wheels up to sell (19" Turbo wheels for a 987.2S if anyone's interested), and left them in the driveway to dry; came back some time later, horrified to see one of the raised sections had burst in the sun and was just hissing away! That's the kind of danger you really need to watch out for; I was surprised, however, that despite a 1" wide slit near the wheel, it wasn't a complete blowout and still took about 10 minutes to hiss down to empty.

The lower-left tire suffered the burst. Would you be tempted to keep driving if your tires only looked like the lower-right, though? 'Cos you really shouldn't.
GvBosa9l.jpg