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TPC (TPMS) issues

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Old 08-21-2021, 05:50 PM
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gsk326
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Wink TPC (TPMS) issues

Hello, I am a new Porche owner, purchased a 2006 911 Carrera cab last week. It runs great, low mileage, drives like a new car, very happy with my purchase.

But,

I am having issues with the TPC. Seems like this is common problem. I have seen old threads discussing this, but nothing recent.



After reset, this is what the tires measure. The front tires are actually inflated to 37, the rears to 44, the recommended factory settings. I had the individual tire pressures rechecked this morning.






This is the message I am getting after relearning; either add air to the front right or front left tire. I have not seen any warning messages regarding the rear tires.

I have tried selecting summer tires, winter tires, full load, partial load; I get the same warning messages.

So the sensors are working but are off by a few PSI, more on the fronts than the rears and that seem to be activating the warnings.

What is the best way to deal with this problem?

Will replacing the sensors fix this, or is there a different issue going on here?

Thank you.
Old 08-22-2021, 08:32 AM
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Petza914
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What size wheels and tires are on the car?
Old 08-22-2021, 10:00 AM
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Bruce In Philly
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2009 C2S 174K miles

So... what you are saying is

1- The air pressures in the tires are known to be particular values via your own pressure gauge. First issue: is your own gauge correct? Have another around to confirm?
2 - The car is initially measuring consistent, but incorrect values.(assuming your gauge is correct)
3 - Then the car changes its measurement and one tire shows up as low, while confirming, using your own gauge, the tire pressure is still as you filled them.

So... either the sensors are sending bogus, changing information, or the car's computer is getting stupid. Usually, as I understand it, the sensors just stop sending information when their batteries are failing, but still send correct data. And, odd that all sensors are incorrect. This points to something wrong with the car and not the sensors. Did you read the computer to see if there are any codes set? Not all codes flip a light on the dash.

Try disconnecting your car battery for 10 minutes. This will "reset" your tire system. Else, your dealer, or a good tire shop, can read the battery levels in the tires. A Durametric can read the health of your TPM system, sensor battery levels, and also reset that particular computer module.

Peace
Bruce in Philly (now Atlanta)

Last edited by Bruce In Philly; 08-22-2021 at 10:03 AM.
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Old 08-22-2021, 02:09 PM
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gsk326
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Thanks for the suggestions.

I have checked the tires with more than one tire gauge. I went back to the after market dealer yesterday where I bought the car and had them check as well. The car is measuring consistent but incorrect values with the lower values in the front tires. Immediately after reset, the front tires measure as low even though they are fully inflated which keeps setting off the alerts.

The rest of the computer functions seem to be normal and everything else is "working".

I have not seen any "bad codes" thankfully. I have only had the car for a week, but it otherwise looks and runs great, like a new car! It only has 34K miles.

The dealer where I bought the car has a great reputation, only sells high end low mileage cars, mostly Porsches, Ferrari's and Lamborghinis . I am dropping the car off there on Wednesday of this week. They are going to take it to the local Porsche dealer in North Scottsdale and at their expense fix whatever proves to be wrong. I will let you know what they find.
Old 08-22-2021, 02:11 PM
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gsk326
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Originally Posted by Petza914
What size wheels and tires are on the car?
19 inch wheels and tires.
Old 08-22-2021, 02:25 PM
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Petza914
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Originally Posted by gsk326
19 inch wheels and tires.
Standard 19" tires? 235/35-19 F and 295/30-19 or 305/30-19 R ?
Old 08-22-2021, 04:39 PM
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gsk326
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Originally Posted by Petza914
Standard 19" tires? 235/35-19 F and 295/30-19 or 305/30-19 R ?
I am up in Prescott today and the Porsche is down at my Phoenix house. I could tell from pictures I have taken of the car that the fronts are 235/35-ZR 19. I cannot read the rear tires from my photos. I will check when I get back to Phoenix tomorrow.

The problem seems to be with the front tires at this time; the sensors readings on the rears are at least pretty close and are not setting off the alert.
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Old 08-22-2021, 06:11 PM
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Floyd540
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Hate to bring it up again, but .1 and .2 systems are different. . 1 seems to have some issues and .2 and even late.2 cars have a more robust system. You will get it sorted out. Enjoy your new car!!!
Old 08-23-2021, 12:13 PM
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G.I.G.
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OK, glad I'm not the only one who struggles with this. Just the other week I rotated my tires side-to-side (not even sure it's really necessary, especially with the rears, but I was bored so I figured why not). After the swap, the TPMS needed to be reset and I did that. Then I got the dreaded -4 PSI warning even though I didn't do anything related to tire pressure when I did the swap. I checked my tire pressure and it was at 36psi in the fronts, 42psi in the rears (cold). Yet my car said I was at 29 in the fronts, and 37 in the rears. I also double checked with another tire pressure gauge which produced the same readings. So I reset it again and didn't receive any low pressure warnings the next time I drove it. As soon as I parked in my garage and turned off the ignition, I got the -4 PSI warning again. I added about 2 psi per tire, then reset the TPMS system again (19" wheels, summer tires, and I have standard size 235 front, 295 rear tires) and it happened again. I put in another 2 psi per tire after that, which finally got rid of the low pressure warning.

OP, my recommendation is to add 1-2psi per tire until the low pressure warning goes away. I've come to the conclusion that A) the TPMS readings on these cars are not very accurate and B) our TPMS systems are very finicky. I've ended up running about the lowest tire pressure I can to appease the computer, which gives me the most amount of grip and road comfort.
Old 08-23-2021, 12:31 PM
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Guys, I've edited this thread title to reflect what the content is actually about - issues with the TPMS (Tire Pressure Monitoring Systems). TPC is an acronym for a vendor and performance shop that makes the DSC suspension module and it has nothing to do with them. I left the original TPC so as not to confuse anyone that it's the same thread but added TPMS so when people search they'll find it.
Old 08-23-2021, 12:57 PM
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Hm I'm going to have to do some annoying poking around with my pressure. I just took my car in for an annual service and when I drove it back it was fine, but the second time I started it up it threw the "TPM Inactive" error at me. I just took my car to the mechanic as a new customer so I don't want to phrase it indelicately, but no work was done on my tires (it was just an oil change/brake line flush and checking codes, etc.) and the TPM worked just fine prior to me taking it in.
Old 08-24-2021, 10:48 PM
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gsk326
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Originally Posted by Petza914
Standard 19" tires? 235/35-19 F and 295/30-19 or 305/30-19 R ?
Fronts: 235/35/ ZR 19

Rears: 295/30/ZR 19
Old 08-24-2021, 10:57 PM
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Originally Posted by G.I.G.
OK, glad I'm not the only one who struggles with this. Just the other week I rotated my tires side-to-side (not even sure it's really necessary, especially with the rears, but I was bored so I figured why not). After the swap, the TPMS needed to be reset and I did that. Then I got the dreaded -4 PSI warning even though I didn't do anything related to tire pressure when I did the swap. I checked my tire pressure and it was at 36psi in the fronts, 42psi in the rears (cold). Yet my car said I was at 29 in the fronts, and 37 in the rears. I also double checked with another tire pressure gauge which produced the same readings. So I reset it again and didn't receive any low pressure warnings the next time I drove it. As soon as I parked in my garage and turned off the ignition, I got the -4 PSI warning again. I added about 2 psi per tire, then reset the TPMS system again (19" wheels, summer tires, and I have standard size 235 front, 295 rear tires) and it happened again. I put in another 2 psi per tire after that, which finally got rid of the low pressure warning.

OP, my recommendation is to add 1-2psi per tire until the low pressure warning goes away. I've come to the conclusion that A) the TPMS readings on these cars are not very accurate and B) our TPMS systems are very finicky. I've ended up running about the lowest tire pressure I can to appease the computer, which gives me the most amount of grip and road comfort.
Well, I tried your "trick" and it worked. My fronts were set at 37 and rears at 44 and I was getting pressure warnings on both front tires. I reset the fronts to 39, no change to the rears, left them at 44, and no alerts!

Is it a problem to have the front tires "overinflated" just to "trick" the sensors?

Should I still get the TPMS evaluated at the dealer or just wait and see?

Thank you all for your helpful comments.


Old 08-24-2021, 11:06 PM
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ky13
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How old are the TPMS sensors? Could be a sensor battery issue.
Old 08-25-2021, 12:29 AM
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gsk326
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Originally Posted by ky13
How old are the TPMS sensors? Could be a sensor battery issue.
I do not know how old the sensors are. I only recently purchased the car. I have an appointment tomorrow to take the car back to the after market dealer where I purchased the car. The owner said he will probably take the car over to the local Porsche dealer in North Scottsdale and he will have the TPMS system inspected and repaired at his expense.


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