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2009 2.5i Outback PZEV Satin Pearl White, Auto
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Discussion Starter · #1 ·
The TPMS light came on. Checked all the tires and they are 30-31 psi. I'll continue to monitor it but I'm pretty sure this is a false alarm and **** annoying that you have to go to the dealer or a well equipped tire store to get it reset. Neither the deal service or Les Schwab is open on Sunday and the wife is supposed to leave early, early Monday morning on a long business trip.
 

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2008 OB XT Limited; 2002 Impreza 2.5TS
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I had the same thing happen this weekend. Driving up into the mountains, the TPMS light flashed for a while, then came on solid.

I pulled over, but the tires all looked fine. I stopped at the next gas station the pressures were as I had set them. I drove a bit more, and then the light went out.

It did the same damned thing today on the way home, twice (light on, light off, light on again).

Any ideas?

Bimmer
 

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'18 Outback 3.6R Touring
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Check the spare tire pressure if it is full size and with TPMS ... I know toyota rv4 is also monitoring the full-size spare
The subaru TPMS only works on tires that are spinning faster then a certain speed so the spare tire, if it includes a sensor, is in standby mode and is not transmitting.
 

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I had the same thing happen this weekend. Driving up into the mountains, the TPMS light flashed for a while, then came on solid. . . . Bimmer
Flashing light indicates functional problem in the system (e.g. weak signal from a sensor, bad connections to TPMS module, or internal failure in the module) similar to the warning lights for other functions. A steady light indicates a low pressure situation.

When the flashing light is experienced, a trouble code is set in the TPMS module and can be read by a dealer's Subaru Select Monitor -- this would indicate what caused the light to come on. Also, I believe the TPMS module can be read to indicate the wheel that recorded a low pressure.
 

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2008 Subaru Outback 2.5i-Auto. 2013 Subaru Outback 2.5i CVT Premium, Cypress Green
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Donut spare does not have a TPMS sensor. And if you put a full size spare with TPMS in the spare cavity it won't be read. The Subaru system will only read 4 tires.
 

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Flashing light indicates functional problem in the system (e.g. weak signal from a sensor, bad connections to TPMS module, or internal failure in the module) similar to the warning lights for other functions. A steady light indicates a low pressure situation.

When the flashing light is experienced, a trouble code is set in the TPMS module and can be read by a dealer's Subaru Select Monitor -- this would indicate what caused the light to come on. Also, I believe the TPMS module can be read to indicate the wheel that recorded a low pressure.
I read the owner's manual last night, and I think it said the opposite: flashing is low pressure, and solid is a system failure.

Anyway, the light's off again, but I've got an appointment at the stealership Wednesday morning.

Just in time: I'm three weeks from the warranty running out!

Bimmer
 

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2009 2.5i Outback PZEV Satin Pearl White, Auto
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Discussion Starter · #9 ·
TPMS is a great idea but Subaru did a terrible job of implementing. For the few dollars more it would have cost it should tell you at a minimum which tire. If it's a faulty sensor all tires are going to read fine so you have only a 25% chance of guessing where the problem is. They also should be reporting temperature since that changes pressure and it can help prevent a blowout. TPMS doesn't report over pressure which is what you'd see from heat caused by a delaminating tire just before it explodes. TPMS was government mandated and Subaru did the absolute minimum to comply. They get a failing grade on this one.
 

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. . .Anyway, the light's off again, but I've got an appointment at the stealership Wednesday morning. . . .
Please do let us know what the dealer finds.

While appearing to be fairly simple, the way the TPMS actually works in practice seems to be less clear. Knowing whether in fact the system does record trouble code data and what it actually indicates (level of detail) to the technician would be a useful addition to the general knowledge base here. (The FSM suggests the code data should be there, but your's is a practical case which is a good test.) If you can be right there when they work on it to see, great; alternatively, hopefully they will provide a detailed report on exactly what they find.
 

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Owner of several Subarus...for my money, the TPMS is another money making scam for dealerships and tire stores. Place a piece of black tape over the sensor and go back to checking your tire pressure once a month the old fashioned way; with a good quality tire gauge.
 

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Twilight Blue 2015 3.6R with Eyesight
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When I had my 09 Outback, I kept my tires @ 36 in front and 33 in the rear. Anything under 30psi would trigger the TPMS. By you keeping your rear tires @30psi, you're right on the bubble for the TPMS to trigger, especially on cold days.
 

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Owner of several Subarus...for my money, the TPMS is another money making scam for dealerships and tire stores. Place a piece of black tape over the sensor and go back to checking your tire pressure once a month the old fashioned way; with a good quality tire gauge.
Please explain how a safety feature that alerts the driver of a possible tire failure a "Scam"?
 

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By you keeping your rear tires @30psi, you're right on the bubble for the TPMS to trigger, especially on cold days.
This would make the light come one and stay on. And that's great because then you know to stop and top of the tires. Great safety option and will help extend the life of your tires.

What seems to be the negative issue here is that the light comes on and blinks. You stop to check pressure but everything is perfect. If you turned the car off to check tire pressure the blinking light probably went off, but maybe 20 miles later it starts blinking again. The real kicker is it is not consistent enough of an issue to take the time to go pay the dealership to look into it.

It is certainly not a scam but a feature that most could and have made do without. I still wish my 05 had roll down crank windows. Less to break is less of a headache.
 

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The TPMS light came on. Checked all the tires and they are 30-31 psi. I'll continue to monitor it but I'm pretty sure this is a false alarm and **** annoying that you have to go to the dealer or a well equipped tire store to get it reset. Neither the deal service or Les Schwab is open on Sunday and the wife is supposed to leave early, early Monday morning on a long business trip.
The reason your light came on is because were going into winter and your pressure was 30psi. When it starts getting cold out people start complaining about their tire pressure TPMs turning a warning light on. Its because your tires are marginally meeting the pressure when its warm out and falling below the PSI over night when its cold.

Not a big deal for sure not worth a Dealer visit. LOL

Put more air in your tire.
 

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2009 2.5i Outback PZEV Satin Pearl White, Auto
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Discussion Starter · #17 ·
The reason your light came on is because were going into winter and your pressure was 30psi.
Yep, happened again just a couple of weeks ago as the weather got colder. All four tires were down to 30psi in the morning. But this time of year it's not uncommon for the temp to be 45 degrees at 6AM and 75 by 4PM. Yes, you can put more air in the tires; although I don't see the wife dragging out the compressor in her work cloths and airing up all four tires. And 30 psi??? If there's truly horrid traction conditions dropping the pressure to 30 psi is exactly what the doctor ordered.

What's really annoying is when the reset between summer and winter tires doesn't take at the dealer. This seems to happen about half the time no matter who I go to to do the switch over. Drive away and everything looks just fine. Next morning you get in and the low pressure warning is on and the only way to get it reset is another trip back to the tire store that has the magic reset machine. Pairing these things up should be a built in function.
 

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Yep, happened again just a couple of weeks ago as the weather got colder. All four tires were down to 30psi in the morning. But this time of year it's not uncommon for the temp to be 45 degrees at 6AM and 75 by 4PM. Yes, you can put more air in the tires; although I don't see the wife dragging out the compressor in her work cloths and airing up all four tires. And 30 psi??? If there's truly horrid traction conditions dropping the pressure to 30 psi is exactly what the doctor ordered.

What's really annoying is when the reset between summer and winter tires doesn't take at the dealer. This seems to happen about half the time no matter who I go to to do the switch over. Drive away and everything looks just fine. Next morning you get in and the low pressure warning is on and the only way to get it reset is another trip back to the tire store that has the magic reset machine. Pairing these things up should be a built in function.
Its just a source of info you see the light you check to make sure you don't have a flat and then get in and go. No big deal. My Toyota has had the light on since 2011 the batteries in the sensors are dead. No big deal I check the tires like the old days and get in and go.
 

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Discussion Starter · #20 ·
Good idea, not so great implementation. I think it's worth it enough that I paid for sensors in my winter tires that I keep on separate rims. But, how hard would it have been to at least tell you which tire was low? I know other cars do that. Maybe it's just a switch (likely) that goes off at a certain level but what would really be helpful is an actual readout of the pressure in each tire. And as for safety knowing the temperature is the really important thing. You can sort of guess a tire is overheating if you see the temp go through the roof. But catastrophic tire failure is usually from the belts coming apart and the early warning clue is the tire temperature heating up. When towing our trailer I have an IR gauge that I point at each tire at rest stops. Bad information is sometimes worse than no information. You count on the TPI but then get used to seeing so many false alarms that you ignore it.
 
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