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SO today I was driving and everything was fine and normal with my car. I parked it and when I got back into my car I started it up and before even driving I got the low tire pressure warning light. It -4 in the rear driver side, but the weird thing is on my dash it shows the tire pressure as being even on both sides. I also checked all 4 tires and they all seem to be the correct psi. I just got new sensors 2 years ago so I thought they would last longer than that. Is this a TPMS malfunction? Is the dash tire pressure monitor running off the TPMS? Im confused as to why it would show on the dash as the correct psi but then also have the low pressure warning light? Is there a way to reset the tpms?
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Only way I know to force a reset is to change tire type and then change it back to correct type. Should go into learn mode. Takes a little while driving to complete.

Might try adding a psi or two to see if the warning is cancelled.
 

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SO today I was driving and everything was fine and normal with my car. I parked it and when I got back into my car I started it up and before even driving I got the low tire pressure warning light. It -4 in the rear driver side, but the weird thing is on my dash it shows the tire pressure as being even on both sides. I also checked all 4 tires and they all seem to be the correct psi. I just got new sensors 2 years ago so I thought they would last longer than that. Is this a TPMS malfunction? Is the dash tire pressure monitor running off the TPMS? Im confused as to why it would show on the dash as the correct psi but then also have the low pressure warning light? Is there a way to reset the tpms? View attachment 269637
On my 2010 BS the low pressure signal is for one or more tires being too low. With an outside temp of 87 F, the 30 PSI on the two tires are probably both too low. Put air in both and see if the pressure sensor warning light doesn't go off.

IIRC there is info in the owners manual on how this works, including temperature effects, etc.

Good luck,

Joe Henley
 

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2008 Cayman S and 2010 GT3
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I hate those tire sensors... the only reason i like them is Incase you have a failure you might find out a few seconds earlier.. as for the in accurate readings, hate’m
 

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Moral of the story, I don’t like relying on gizmos to do things I’d prefer doing myself so I know it’s right... track days, I have a gauge glued to my hand
 

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While we are on the subject do they even make a good tire gauge in these days? A lot of the ones I see are crap and inaccurate. I still have two pencil style gauges from the seventies that I received from Esso or could have been Atlas. I hope I never lose them as I once purchased look alike units for my boat and they were junk. These old ones are even heavier, I also have a free dial from some auto magazine that I don't trust.
 

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I got mine off grassroots Motorsports mag... it’s a round gauge style, works good... great magazine!! Everyone should subscribe

that’s my GRM plug for the day 🤪
 

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Hi guys,

I have a high accuracy tire pressure guage; wouldn't be without it. When I got the "new to me" 2010 BS, I compared the dash TPMS readings to the guage readings about once or twice a week for several months, then radomly for 6 to 8 months thereafter. Pretty much dead nuts accurate. The guage reads in tenths, the TPMS in whole psi; never missed within rounding tenths up or down.

I'm sure there are plenty out there which are no longer (maybe never were) accurate; that's why I recommend folks to do a careful comparison check. Once you've done that, the TPMS is great to advise you of a slow leak, or that once every season temperature / pressure change.

Joe Henley
 

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I have a good Longacre dial gauge that I have used for several years. Durable and accurate. Forget about the pencil-style ones.
 

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Agree the Longacre's are good quality but still affordable. If you're paying a buck or two for a pencil tire gauge you'll get a buck or two worth of accuracy. Plan accordingly.
 

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My 2013 981 Boxster S's TPMS system matches my analog tire pressure gauge exactly. I can really see how the sun, driving and hard cornering affects the tire pressure. I had my sensors replaced w/factory sensors at 6 years when I put new Michelin PS4s on to replace the hateful P-Zeros. It took about two weeks for everything to sort itself out but now it works perfectly. I fill with nitrogen in the AM, when cold, to factory specs before driving. It seems to only set off the TPMS when there is a big differential between tires, what ever the reason. And, yeah, the lack of the oil dip-stick is booooo-oooo-oooo-gus.
 

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I am experiencing exactly the same TPMS behavior in my 2013 Cayenne. It never happened in my Boxster. I bought the Cayenne in Feb and use it to tow my boats. I had my independent shop go over it and everything has been fine until this week on an extended road trip the low tire warning showed up the same way you described but the reported pressure matches the other front tire. I checked with a manual gauge but that indicates the same as TPMS. I added air anyway just to check but that doesn't stop the warning when I start up. While I am driving it will go off somewhat randomly almost any time. As soon as I get home I'm going to have the sensor replaced. I have no idea how old they are but the only solution I can think of is to replace the sensor.
 

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2008 Cayman S, Tiptronic
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Longacre Make a good dual gauge. I use a Motion Pro digital. Really enjoy it. Had it four years and still on the original battery.
 

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Agree with 08, frankly I also prefer an oil dipstick unless the path is so convoluted you can never get a good read.
Off Topic of the TPMS warning indicator issue (which I'm also am experiencing) ... is there a way to add an oil dipstick on the 987-1 motor? I'm a bit leery of the accuracy of the electronic sensor.
 

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SO today I was driving and everything was fine and normal with my car. I parked it and when I got back into my car I started it up and before even driving I got the low tire pressure warning light. It -4 in the rear driver side, but the weird thing is on my dash it shows the tire pressure as being even on both sides. I also checked all 4 tires and they all seem to be the correct psi. I just got new sensors 2 years ago so I thought they would last longer than that. Is this a TPMS malfunction? Is the dash tire pressure monitor running off the TPMS? Im confused as to why it would show on the dash as the correct psi but then also have the low pressure warning light? Is there a way to reset the tpms? View attachment 269637
My 2011 Boxster and 2007 Cayman has done this to me several times. I have put it in the learning mode and the problem fixes it self until I turn off the key and next time I fire it up the problem reappears. I solved it by disconnecting the battery for a few minutes and relearning the sensors.That cleared the issue right up.
 

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It's my experience that these TPMS systems, at least in my 987.1, are prone to outside interference. It's not unusual for a service van from XYZ or whoever, will drive up next to me and my system will go blank. It also regularly, but not always, goes blank when I drive by a local fire house. It comes back in a couple miles but I've determined that it reacts to an overly strong 433 mhz signal from another source when it gets close to one. I have also had success in resetting mine by cycling through a reset as though I had changed tire sizes and then returned it to the correct size. I don't have this problem with my other vehicles.
 

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SO today I was driving and everything was fine and normal with my car. I parked it and when I got back into my car I started it up and before even driving I got the low tire pressure warning light. It -4 in the rear driver side, but the weird thing is on my dash it shows the tire pressure as being even on both sides. I also checked all 4 tires and they all seem to be the correct psi. I just got new sensors 2 years ago so I thought they would last longer than that. Is this a TPMS malfunction? Is the dash tire pressure monitor running off the TPMS? Im confused as to why it would show on the dash as the correct psi but then also have the low pressure warning light? Is there a way to reset the tpms? View attachment 269637
Got tired of false/irregular readings, so for $5 a tire I replaced air with nitrogen. In Alabama where we have seasonal temperatures that vary from one extreme to another (102° temp yesterday) TPMS readings haven't varied. If NASCAR, major airlines, and the Navy uses it in their vehicles & aircraft, it's enough of an endorsement for me. It extends tire wear as well.
 

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Some commercial business and 'official' government agencies, including police and fire departments, utilize the UHF radio band near the 433 mHz frequency. 433 mHz actually lands in the lower portion of the Amateur Radio UHF band (420 to 450 mHz).
 
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