KeninBlaine

My TPMS typically reads 3 psi lower than my measured pressures, so when one of my tires drops only 1 psi, it gives me a TPMS warning on the dash suggesting I'm down 4psi, which is apparently the threshold for a warning message. I normally run 33 front, 36 rear, so the TPMS measures 30 front & 33 rear. If it drops to 35 psi on a rear, the TPMS thinks it is 32, which is 4 psi below the minimum 36, and triggers a warning. Today, after topping up the pressures with an extra 1 psi for margin (to 34 front, 37 rear), the warning refuses to go away for my left rear, even though both rears are now at 37 psi, and after multiple stops and starts of the car. How can one clear these frustrating and erroneous warnings?
Also, if I were to mount non-TPMS wheels, is there any way to disable TPMS altogether?

996toomey

Yes it can be disabled if you can find a dealer to do it for you. There is a thread in the 997GT3 forum by Mooty explaining how it is done.

To clear the warning light inflate the tires higher than you might normally and then adjust pressures back down after you clear the warning light. So in other words put 40 & 44 in and go for a short drive make sure light is out and then adjust pressures back down to where you want them.

Also you can have the dealer tech adjust the "Bars" in the system to where it will take a greater loss of air to trigger the warning light. This is not a normal dealer procedure so it helps to have a good relationship with your Master Tech.

MLindgren

As unreliable as this system seems to be based on posts I can't believe it isn't easily disabled by the user.

Waiting for the pro TPMS posts to start......

ADias

What is the 'pro TPMS' ?

I noticed that order books for the new 997.2 do have a TPMS option. Is that new? I thought that all US-bound cars had TPMS as std.

KeninBlaine

I believe "pro TPMS" was meant to describe any benefits of TPMS.

bet

Given the general inaccuracy of TPMS and the fact that virtually no one uses run flats on their Porsche (is there even a run flat in the proper size?....god forbid it won't be N spec.) I am still trying to figure out any advantages of the TPMS. Oh wait is sounds cool when you say I have a tire pressure monitoring system on my car...that is an advantage right?

I guess in theory for the person that runs the factory pressures and does not check tire pressures regularly then when a tire does lose pressure the system would notify the driver and it could be corrected prior to wear issues. That is the best I have...weak I know. In real world applications with people running pressures lower than factory recommendations and/or track usage, TPMS is annoying as all get out.

flash1034

TPMS was mandated by the feds in response to the Firebomb (Firestone) and Ford Exploder (Explorer) Rollover debacle.
Flash

KeninBlaine

Ummmm.............. HUH?

Minok

Remember the issue with the Explorers rolling over en-mass because the Firestone tires were blowing out?

Not sure how TPMS would help there, as it was a case of drivers driving too aggressively for an SUV in combination with what I'm guessing are tires with not enough extra capacity beyond the limits to allow for this.

gota911

Apparently, after much testing, they concluded that under inflated tires dramatically increased the potential for a blow outs. Rocket science, you know?

Solution: Goverment mandated TPMS.

daddyscar

Saved me once but have had four false alarms since. First time a warning alerted me to nail in my tire. Than one at a time, each other tire gave me a warning. I first tried lowering the tire pressure than adding over 4 psi, negative. I than tried lowering the tire pressure, let the car sit overnight, than adding over 4 psi, negative. Best thing to do as mentioned is put over 4 psi from when you get the warning. Cruise around until the warning goes away, than adjust the tire pressure down.

Chris from Cali

I also appreciated it for a slow leak a nail in the inside sidewall was giving me... It's an annoying thing overall though, not to mention pricey. I have a set of summer and winter wheels/tire for my RS4, so I had to buy a second set of TPMS sensors for the other set of wheels. Not money I wanted to spend.

Mussl Kar

TPMS was handy when it alerted me to a nail in my tire at Lime Rock. Other than that it is a major PITA if you change tires a lot.

KeninBlaine

Yes, I remember the whole Explorer roll-over thing, But I haven't seen any evidence of government mandated TPMS. It is only an option on a very small number of cars.

Leader

From Wikipedia the (questionable) source of all internet knowledge (although in this case I think the info is good):

The Firestone recall in the United States in the late 1990s which was attributed to more than 100 deaths from rollovers following a tire tread-separation, pushed the Clinton administration to publish the TREAD Act. This act mandates the use of a suitable TPM technology in order to alert drivers of a severe under-inflation condition of their tires. This act affects all light motor vehicles (<10,000 lb) sold after 1 September 2007.

Phase-in started in October 2005 at 20%, and reached 100% for models produced after September 2007. While in the US, TPMS legislation grew from safety-related motives, European Union (EU) and Far East legislators are looking at TPMS as a way of reducing CO₂emissions, and are presently considering compulsory Tire Pressure Monitoring Systems from this environmental stance.

I believe this means all cars (<10k lbs) produced after Sept. 2007 will have some form of TPMS. It's not an option any more. Oh joy.