I took the car to Porsche of Arlington and they were unable to re-set the TPMS without over-inflating the tires. They have ordered me a new TPMS module and two new tire monitors for the front. They already replaced the rears. Gotta say that they are doing their very best.
Mr. B

 

OK, today I dropped the car off at the dealership for a new TPMS module, plus two new tire monitors for inside the front rims.
The dealership already installed tire monitors in the rear rims.
This should solve the problem (I hope).
Anyway, it's all covered under the CPO warranty.
Mr. B

 

Cool I think they module is the culprit as mine does not do this. Goodluck and this is why CPO is good to have

 

IMHO, CPO is the ONLY way to go!!
Mr. B

 

So, after many months of having NO problems whatsoever, the yellow tire symbol light is lit again and the TPMS is telling me that one or more tires are under-inflated. A check with a very accurate gauge shows that the tires are fine.
Boy, is this ever frustrating!
Mr. B

 

Seriously considering disabling TPMS. Bought after-market wheels (TechArts) and had local shop put them on with the TPMS. I get Warnings EVERY time I fire up my CS. Yes...I check pressure regularly. Thought it was my aftermarket wheels. I feel better now that I know you are all suffering with me. :') Misery loves company.

 

How warm is the ambient temperature when you are checking pressures? Baseline for TPMS to properly calibrate is something like 60 degrees F and cold (not driven on) tires. If, for instance, the ambient temp is 80 degrees and if you set pressures per spec (33/39 for my 997 Turbo) TPMS will error out as it "thinks" the pressure should be higher for the given ambient temp. Same thing applies if you are checking in direct sunlight which can cause pressures and TPMS readings to vary side to side.

When I'm at the track, I run 32/35 hot. TPMS error messages abound! When I leave the track, ie tires are still very warm to hot, I fill to 45/50 which resets the error messages, drive 225 miles home, park in the garage and the next morning when temps are 60-ish, make a final adjustment; usually bleeding off 2 or 3 lbs. That procedure works well for me. That said, the TPMS system still is a real pita! Best,

 

It's summer here--high 80's.
Mr. B

 

You probably need to add 2-4 lbs more to whatever your baseline pressures are to compensate for the higher ambient temps. That should allow the TPMS system to "think" that pressures are appropriately increasing as the temperature increases. You might also check your owners manual (or any other official Porsche publication you received with your car) as I recall seeing a graph somewhere that plotted temperature vs pressure which will give you an idea of where you need to be to keep the system "happy" under varying conditions. For a computer based system, it really ain't very smart.......

 

Took the car to the dealership (Porsche of Arlington in VA) and they re-programmed the TPMS with updated software, and the problem is fixed!!
It's great to have that CPO warranty!!
Mr. B

 

Mr. B, has it given you any problem after the software update?

 

No problems whatsoever!!
Mr. B

 

Good to know. I'll go that route next weekend.

 

PLS let me know how that works out for you,
The dealership that did the job for me was Porsche of Arlington in VA.
Mr. B

 

For sure.