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Will TPMS detect high pressure in the spare?

My TPMS warning light came on last week and after finding the four tires on the road were all fine, I decided to wait until the weekend to check the spare. It was low, so I aired it up and the warning light is gone.

Now after struggling with the spare tire cover, I wonder if I should run the spare up to 40 or so to prolong this happening again.

Next time I have the cover off I'll try this and report back.

Thanks
 

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The TPMS works on the spare too. Not sure if it reacts to overly high pressure.
 

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Will TPMS detect high pressure in the spare?

My TPMS warning light came on last week and after finding the four tires on the road were all fine, I decided to wait until the weekend to check the spare. It was low, so I aired it up and the warning light is gone.

Now after struggling with the spare tire cover, I wonder if I should run the spare up to 40 or so to prolong this happening again.

Next time I have the cover off I'll try this and report back.

Thanks
For some reason, I'm under the impression it only acts on low, not high. I do what you mentioned, keep about 40 or so in the spare. No problems.
 

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I keep 40 PSI in the spare and check it twice a year. I agree that taking off that spare tire cover is a giant PIA. The TPMS will come into play when tire pressure is LOW.
 

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I purchased 4 new tires from Costco a few weeks ago. I haven’t driven much since then. Friday I was out on a longer drive (about 80 miles RT) and on the way home, the TPMS light on the instrument cluster came on flashing and then went solid yellow. I checked the tires visually on the way home and they all looked OK. When I got home, the tires were all nominal, 36 PSI for the new tires and 32 PSI for the spare. I checked the new tires again this morning and they’re all nominal 32/33 PSI as they should be. The light on the IC comes on flashing at start and then stays on solid yellow. The spare is the original spare tire. The spare has never been used (always rotated tires front to back). I have an appointment with Costco to check the new tires, but I’m wondering if the sensor in the spare has gone bad/no longer transmitting due to low power. Is there any way for me to check which tire is causing the problem? If it is the spare, I would like to simply get the sensor replaced with a new one. Given the age of the tire, would any shop do that? Obviously I have not used the tire in 13 years and I don’t intend to use it except in emergencies, like a donut tire. Is there any way to tell the car sensor apparatus not to look at just the spare tire?
 

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I purchased 4 new tires from Costco a few weeks ago. I haven’t driven much since then. Friday I was out on a longer drive (about 80 miles RT) and on the way home, the TPMS light on the instrument cluster came on flashing and then went solid yellow. I checked the tires visually on the way home and they all looked OK. When I got home, the tires were all nominal, 36 PSI for the new tires and 32 PSI for the spare. I checked the new tires again this morning and they’re all nominal 32/33 PSI as they should be. The light on the IC comes on flashing at start and then stays on solid yellow. The spare is the original spare tire. The spare has never been used (always rotated tires front to back). I have an appointment with Costco to check the new tires, but I’m wondering if the sensor in the spare has gone bad/no longer transmitting due to low power. Is there any way for me to check which tire is causing the problem? If it is the spare, I would like to simply get the sensor replaced with a new one. Given the age of the tire, would any shop do that? Obviously I have not used the tire in 13 years and I don’t intend to use it except in emergencies, like a donut tire. Is there any way to tell the car sensor apparatus not to look at just the spare tire?
You can check which one is bad using Techstream software. That means you also need to buy the mini vci cable. The software will come with the cable and you can download the latest version if you Google. If one TPMS is bad usually the rest are not that far behind.
 

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Thanks, I was going to try to add air to see if it works.

PS: Wow. He is one of them guys that keeps 40psi in his tires. Because...Toyota's engineers are morons?
 

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Yep - 40 psi in my road tires as well, helps a lot with handling on our twisty mountain roads, may yield a marginal increase in fuel mileage. 45 psi in the spare as does RTexasF.
 

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Thanks for the replies. After consideration, I think I will keep the appointment at Costco and let them figure it out. If it is one of the new tires, then they can just replace the offending sensor (under warranty) and I'll move on. If it is the sensor on the spare, between Costco and myself we'll figure out what to do. I very well might have to resort to a judiciously-placed bit of electrical tape over the tire warning light on the cluster! I really wouldn't use the Techstream device for anything other than this, and besides, even if I did determine that the offending sensor is on the spare, I'd still have to get it fixed somewhere. I don't have the capability (or desire) to dismount/mount and balance a tire. After spending almost $700 on new tires (with a discount deal on no less) I don't really have the stomach to pay full price for a matching spare that I may never use. Hard to believe that an unused tire, even an old one, couldn't get me around town or to the next exit. In the meantime, I'll drive the old-fashioned way by checking my tires before setting out on a trip. I'm old enough to remember when vehicles didn't have this fancy gadgetry and...somehow...we got along just fine!

Just to be clear, what happened was that I got four new tires (Michelin) on the wheels that contact the ground, the ones I drive on. The spare is still the original tire (Bridgestone, I think) that has always sat on the spare tire mount on the door and has NEVER been used, not once, in 13 years.
 

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Yep - 40 psi in my road tires as well, helps a lot with handling on our twisty mountain roads, may yield a marginal increase in fuel mileage. 45 psi in the spare as does RTexasF.
I strongly believe that's just placebo thinking. I trust all the car manufacturers engines when they put 32-35psi on those labels, and not the max those tires can handle. One can increase the pressure if the car is loaded more, but most of the time they drive just with one driver.

Higher pressure makes the contact patch smaller, so that's less grip - in turns or braking.
Also, when it hits high-frequency bumps (like small cracks in the road, expansion joints, etc), instead of absorbing the shock energy, it just provides a jarring, instant, reaction force, that diminishes further the rubber contact pressure with the asphalt. If you want the wheel "jumps" instead of staying compliant on the same path.
With high pressure, when I hit those joints in a turn (highway cloverleafs), at my relative high speed (high lateral g), I can feel the car "sliding" sideways when bouncing off those cracks. Shocks can take care only on low-frequency bumps, cannot react that fast.
In final, those jarring forces are transmitted to the suspension components (instead of being absorbed by the air and tire wall rubber), and usually the rubber bushings take the blunt. I can't imagine that being good for them.

Anyway... more power to you.
 

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I strongly believe that's just placebo thinking. I trust all the car manufacturers engines when they put 32-35psi on those labels, and not the max those tires can handle. One can increase the pressure if the car is loaded more, but most of the time they drive just with one driver.

Higher pressure makes the contact patch smaller, so that's less grip - in turns or braking.
Also, when it hits high-frequency bumps (like small cracks in the road, expansion joints, etc), instead of absorbing the shock energy, it just provides a jarring, instant, reaction force, that diminishes further the rubber contact pressure with the asphalt.
With high pressure, when I hit those joints in a turn (highway cloverleafs), at my relative high speed (high lateral g), I can feel the car "sliding" sideways when bouncing off those cracks. Suspension takes care only on low-frequency bumps, cannot react that fast.
In final, those jarring forces are transmitted to the suspension components (intead of being absorbed by the air), and usually the rubber bushings take the blunt. I can't imagine that being good for them.

Anyway... more power to you.
Actually, I've always run a few PSI higher than what's listed on the door. I have always made sure to stay well under the max pressure listed on the tire. I dunno that it makes much of difference either way, certainly fuel is inexpensive enough that saving even a mile or two per gallon isn't going to make a huge difference in the long run. And, I've had even supposedly "good brand" tire pressure gauges (good ones, round gage, not the cheap stick types) vary by a couple PSI. I think the biggest thing is getting all four tires at the same PSI.

I agree with the handling observations. Although, two things: 1) Tires vary tremendously in handling and "grippiness." The Michelins we got on our Sienna have been fantastic. Just love them. These new Michelins on my RAV are, arguably, new tires, but even at a couple PSI over the door recommendation they feel and handle great. 2) My wife actually wanted the RAV when we bought it, I was OK with it at the time but it has won my heart and mind and now you would have to pry it out of my cold dead hands! Now, she prefers driving the van because the RAV is, well, a truck, to be honest, and it drives like one, plus the van has more space for her stuff. You could put cotton candy on the RAV's wheels and it would still have a harsher ride. I don't mind it, I prefer "feeling" the road and I am used to the way the car handles. For around town and doing errands, back and forth to work and such, it has been a nice dependable little workhorse.

The other observation is that Costco puts nitrogen in the tires, which is fine, but as a guy put it in an article I read, it probably does as much good as rubbing a tiger skin over your engine cover. "Air" is mostly nitrogen anyway!
 

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Thanks for the replies. After consideration, I think I will keep the appointment at Costco and let them figure it out. If it is one of the new tires, then they can just replace the offending sensor (under warranty) and I'll move on. If it is the sensor on the spare, between Costco and myself we'll figure out what to do. I very well might have to resort to a judiciously-placed bit of electrical tape over the tire warning light on the cluster! I really wouldn't use the Techstream device for anything other than this, and besides, even if I did determine that the offending sensor is on the spare, I'd still have to get it fixed somewhere. I don't have the capability (or desire) to dismount/mount and balance a tire. After spending almost $700 on new tires (with a discount deal on no less) I don't really have the stomach to pay full price for a matching spare that I may never use. Hard to believe that an unused tire, even an old one, couldn't get me around town or to the next exit. In the meantime, I'll drive the old-fashioned way by checking my tires before setting out on a trip. I'm old enough to remember when vehicles didn't have this fancy gadgetry and...somehow...we got along just fine!

Just to be clear, what happened was that I got four new tires (Michelin) on the wheels that contact the ground, the ones I drive on. The spare is still the original tire (Bridgestone, I think) that has always sat on the spare tire mount on the door and has NEVER been used, not once, in 13 years.
It's not clear to me, did Costco replace the sensors on the 4 new tires they installed? If not, why not? They're 13 years old!
If they did replace only the 4 and not the spare, then as you say, let them figure it out. If it turns out to be the spare tire sensor, just replace the sensor, not the tire.
I have the same situation as you, I need 4 new tires and the spare on my 2010 has never hit the ground so I'll keep it, BUT, I will have them replace all 5 sensors and just put the spare back on the door.
 

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It's not clear to me, did Costco replace the sensors on the 4 new tires they installed? If not, why not? They're 13 years old!
If they did replace only the 4 and not the spare, then as you say, let them figure it out. If it turns out to be the spare tire sensor, just replace the sensor, not the tire.
I have the same situation as you, I need 4 new tires and the spare on my 2010 has never hit the ground so I'll keep it, BUT, I will have them replace all 5 sensors and just put the spare back on the door.
Costco should have put new sensors on the 4 tires they installed - they charged me for it("TPMS Service Pack - Generic").
 
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