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TPMS Sensor Info for Subaru Outbacks

97K views 213 replies 69 participants last post by  Phillyjudge  
#1 · (Edited)
Anyone with better information please let me know and I'll get it corrected.

TPMS History:

In the 1990s Firestone tires blew up on Ford Explorers. After a public back and forth the powers that be agreed to mandate tire pressure monitoring system on future vehicles. The law went into effect on 9/1/2007 and all vehicles sold in the US since have had some sort of Tire Pressure Monitoring System, or TPMS.

TPMS Function:

What this system does is use sensors in the tire to measure the tire pressure. When the pressure in the tire gets below a certain threshold (27 PSI) a warning light comes on on the dash warning of potential hazards from low tire pressure. The newer (2018+) systems have the capability to individually read each tire's pressure from the dashboard.

TPMS Components:

Subaru has used two types that I'm aware of:

2008-2017 Model Years used a 315 mhz system.

2018-2019 Model Years uses a 433 mhz system.

A user could take the 315 mhz sensors from compatible years and program them into the car computer and have it function fine.

The only issue with doing this is the if you swap wheels they will have to be relearned into the car.

I used the Schrader Red Sensors on my 2017 to clone the 315 mhz system. I can now swap the wheels on the car without relearning.

I have been told the Schrader EZ Sensor will also function the same but do not have first hand experience doing so.

For the 433 mhz system Schrader 33700 EZ Sensors will clone, according to @DugsSin

@Fibber2 Any input?
 
#63 ·
My 2015 used to bug me as well in cold weather, until I started putting an extra 1lb of air in them all, problem solved, and it really hasn't affected the tire performance.
 
#11 ·
For the record, it was my 2019 but it should be the same for 2018 and later.

Anyone know if you get aftermarket wheels if the OEM sensors will fit? I'm looking at wheels with an offset of 47 compared to the OEM 55. Size would be the same.
Although my OEM wheels and sensors are in the shed, I believe any aftermarket wheel that takes a standard valve stem could use the OEM sensors. Perhaps if the valve stem opening on the aftermarkets is in a weird position on the side or near a weird groove or something the pressure transducer wouldn't fit, but I think that would be a rare occurrence.
 
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#10 ·
Anyone know if you get aftermarket wheels if the OEM sensors will fit? I'm looking at wheels with an offset of 47 compared to the OEM 55. Size would be the same.
 
#12 ·
I have a 19 OB 3.6r (no lift), I am planning to buy some 17x8 WRX wheels off craigslist (no TPMS sensor) and install 225/65r17 on them...

I have some questions or need some advise on TPMS...

-I can get 4 new TPMS sensors from my dealer for $89 each (wholesale price).

-I can get 4 aftermarket TPMS sensors off TireRack for $47 each.

The Autel MaxiTPMS TS508 Tool is $275 on TireRack or $227 on Amazon..

Questions:

Is there any difference between the aftermarket & OEM TPMS sensors in regards to programming and relearning the sensors with the TS508?

Has anyone here purchase the TS508 from Amazon? - there is 1 review stating they received a fake unit.
 
#14 ·
I clicked on the link above, and it reminded me that I'd purchased this unit from this seller on January 7th. Only it was $215 back then! I've had the downlevel model TS408 for nearly 2 years and love it.

There are other very sweet deals out there right now, for example from Advance Auto, where you can get this unit with 8 blank programmable dual band sensors for not a whole lot more cash if you can get one of their 25% off coupons. Register on their site, visit it a few times, put an item or two in your basket and then close your browser. In a week they will offer you an enticement to buy! https://shop.advanceautoparts.com/p/autel-tool-sensors-stems-1-ea-autel-ts508kmv-1/11965363-P With coupon this comes down to $250 !!!

If you go this route you can either duplicate your existing sensors (cloning), or use the tool to upload the codes of the second set of sensors when you rotate in your second set of wheels.
 
#15 ·
Another 25% off at Advance arrived in my email this morning.... Toy with them a little bit and you'll get them too.
 
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#16 ·
Thanks for posting the background of TPMS and operational info. My wife's '08 has reached 11 years since new. I have never toyed around with her Outback other than basic maintenance but imagine I will now be doing more... TPMS is new to me as I drive a 2002 vehicle and do not have it. I took her vehicle on a business trip during the "Wild" Winter Vortex week we had here in late January as I spent that week in Wisconsin. The TPMS sensor dash light came on and I thought something was up but would worry about it when I got home--no obvious tire distress noted. The light went off and I forgot about the incident. Turns out I suppose it relates to the extreme cold as discussed somewhere seen here. This meaning Subaru sensors are finicky. I suspected at the time it was something connected to the extreme cold, -25F for several mornings.
 
#17 ·
he TPMS sensorsThis meaning Subaru sensors are finicky. I suspected at the time it was something connected to the extreme cold, -25F for several mornings.
No, no problem with the TPMS sensors. Consider that tire pressure drops ~1 psi for every 10 degrees (F) drop in temperature. At -25F, your tire pressures were actually low.
 
#19 ·
I've searched everything I could find.
On a 2019 Subaru system the only effect with running no sensors
is the warning light correct?
It does not effect anything else such as traction control etc???
This is my understanding - please correct me if I'm wrong
 
#20 ·
Can I simply not install TPMS on a set of winter tires and wheels with a 2019 OB? They're expensive. And pain in the butt to then go calibrate with more expense - as I understand it. I went without TPMS with all my previous cars and simply covered the little warning light with a black piece of tape for the winter. Never any issues. The stupid light never even burned out! But with the ever increasing (and expensive) nanny systems on cars (that I never asked for) I don't know if this is still possible without screwing up the function of something critical.

I monitor my tire pressure the old fashioned way. With a (gasp!) tire gauge.
 
#21 ·
Can I simply not install TPMS on a set of winter tires and wheels with a 2019 OB? They're expensive. And pain in the butt to then go calibrate with more expense - as I understand it. I went without TPMS with all my previous cars and simply covered the little warning light with a black piece of tape for the winter. Never any issues. The stupid light never even burned out! But with the ever increasing (and expensive) nanny systems on cars (that I never asked for) I don't know if this is still possible without screwing up the function of something critical.

I monitor my tire pressure the old fashioned way. With a (gasp!) tire gauge.

I've been driving with the light on after swapping tires for about 8k miles. No issues
 
#25 ·
It is too bad that Subaru have not caught up with the Germans. On my wife's Golf - Instead the TPMS uses the vehicle's anti-lock braking system to track this. The tire pressure monitoring system looks at the ABS wheel speed sensors and uses that information to track the rotational speed of the tires. ... have never had a problem in the 5 years of ownership.
 
#26 ·
Lots of good info on TPMS here - something I know nothing about - so, I have a very simple question. I just bought a 2020 Outback 2.5, Premium. On the smaller dash screen display you can scroll though a number of selections you want to view. One of those is, of course, the little diagram of the four wheel/tires with the indicated TP. By design, when you first start out in the car (a cold start so to speak) the icon does not show any tire pressure numbers but within one-half mile suddenly the tire pressure for each tire is displayed. I guess a half mile of driving might vary with the outside temperature but I am not sure of that. Cold, my tires are inflated to the pressure on the plate just inside the drivers door: That plate recommends: F 35, R 33. As soon as my TPS data is displayed on the dash it has one front tire at 39 PSI and the other three tires at 38 PSI. Is this normal - on the rear that's a 6 PSI increase in one-half mile of slow driving on a 65 Degree F day.
Or, are the TPS dash numbers just a rough estimate?

And, a second unrelated really stupid question which is asked not out of usefulness - just something that popped into my weird brain. A 2020 Outback specs show ground clearance of 8.7 inches.
Will the ground clearance differ with different size wheels - or as the wheel gets a little larger does a corresponding decrease in the tire size. A guy that has an older Outback (2015 I think) told me that the larger wheels, that most people on this forum would prefer, handle better than smaller wheels but that smaller wheels give a little bit better ride. I have no idea if he is right or wrong so will one of you wheel/tire experts sort it out for me.
Thanks, from a new Subaru owner - 1st Subaru - and I don't even have 500 miles on it but so far I love it!
 
#27 ·
welcome and congrats on your new car :)

about tire pressure
get a pressure gauge and use it to crosscheck what your display says

"cold" pressure varies from "operating" pressure by as much as 6psi, depending how cold it was outside when the "cold" pressure was measured, vs how warm it may be outside, in addition to the heat gain from driving.

so to be consistent, get a tire gauge and measure your operating pressure, when comparing to the operating pressure displayed on your dash.. that will get you close to knowing if your dash display is off, or not...

to your bigger wheel question
as the rim gets bigger the height of the rubber between the ground and the metal rim gets smaller

this makes the car drive tighter, less body roll, on good pavement
otoh, a taller profile rubber tire on a smaller diameter metal rim, will make the rubber part relatively more squishy, making the car tolerate rough uneven roads better, but it wont hug dry curves on smooth pavement with as little body roll..

enjoy your car.. :)
 
#29 ·
All, I posted my experience in cloning my OEM TPMS sensors on my 2020 Outback Onyx XT successfully on another thread in this forum: https://www.subaruoutback.org/threads/winter-wheels-tires-for-my-gen-6-cloning-tpms-overview.517492/

Cloning allows me to swap wheels (winter, 3 season OEM) without having to relearn the TPMS in the car. The VT36 tool I purchased supports multiple frequencies and all models of Subarus as well as programmable TPMS sensors like the Schrader EZ-Sensor that I used.

Hope my experience and info helps!
 
#30 ·
I posted this in another thread, but it is probably more useful here. Good alternative to using a programming/relearn tool.

I ordered the following set from TPMS.com, and confirmed with their tech support that they are pre-cloned and activated. They are misinformed that the location (driver front, driver rear, etc) matters for 2018+ I believe, but it is needed to be entered in the comments when you order, for their sake.

TPMS.com pre-cloned sensors

I simply had the dealer give me the TPMS codes assigned to the car the last time it was in for service, entered them into the comments section of my order, they will arrive pre-cloned, ready to install without a tpms tool, or relearning to be done. I listed the sensor by location on the car, per their request (but as we know, is not necessary as the car automatically learns the location of each sensor after driving up to speed). I think this is a great deal at $110 shipped, for a hassle free swap over between seasonal sets of wheels/tires.

I will update once I get them in, and my wheels/tires are mounted and on the car, to confirm that it works as designed.
 
#32 ·
TPMS.com pre-cloned sensors I simply had the dealer give me the TPMS codes assigned to the car the last time it was in for service, entered them into the comments section of my order, they will arrive pre-cloned, ready to install without a tpms tool, or relearning to be done.
This is an EXCELLENT alternative to DIY. Great post! This past fall I used my Autel TS508 and a set of their programmable MX senors to do the same thing for my daughter's Toyota. It still cost me $105 to buy a set of metal stem dual frequency programmables plus my time, so their asking price of $110 for genuine Schrader sensors with rubber stems is great. You won't find them from a legit source for less.

My only comment is why do they charge $10 more for producing a set of pre-2016 cloned 315mhz sensors? The base dual frequency programmable sensor Schrader 33500 EZ sensor is the same, as is the procedure and programming tool. I guess it's because they can.... Capitalism at work.
 
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#31 ·
Question, in the 2020's, how bad is the tpms light? Bout to pick up a set of rims to run winters on next year, but there are no tpms sensors. This all before i get my new car.

On my 2014, I had a set of tpms in my old wheels, but never bothered teaching the car. My tire shop couldnt do it, and it wasnt worth a trip to subaru and $60 twice a year. Was just a little light and electrical tape made me happy.

Do the 2020's light up like a christmas tree? Make any noise? Disable any critical functions? Or is it pretty ignorable?

Frustrating that nanny systems don't want us to switch tires to be as safe as we can be.
 
#33 ·
Maybe someone can solve my TPMS question/problem. It is a long shot - i realize that. I googled and googled and I am getting almost nothing.

My Car: 2008 Subaru Outback XT.
New (used) Wheels coming: 2018 Subaru BRZ Performance Package with tires and TPMS.

TPMS sensors - I was able to determine that in fact 2018 BRZ uses 315mhz sensors just like 2008 Outback. But BRZ seems to have different part number than most Subarus.

a slew of Subarus that take 315mhz (but no BRZ listed):

basically just brz fitment despite also being 315mhz.

So question basically is will 315mhz sensors on BRZ wheels work with my 2008 Outback despite website above showing them as different car fitment.
 
#34 ·
The tip-off for me was that the BRZ sensors can begin with 42607-xxxxx. That's a Toyota number, and at least one of them is a Pacific brand sensor. (I have Subaru / Toyota / Honda vehicles in the fleet). So apparently while the BRZ is indeed part Subaru, the TPMS hardware for that vehicle is sourced from Toyota and is therefore totally incompatible with your 2008 Outback.

See, that really wasn't so hard!
 
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#35 · (Edited)
So glad you got back to me. Thank you. Now when you mentioned it I should have tried to cross reference with Toyota since it’s basically same car. On the flip side I do not like you answer as it means I need to buy a set of TPMS for Incoming used (new to me) BRZ wheels. I was thinking about re-using my OEM sensors but they are 12 years old. I am not sure how it is possible they still work :) so given that - new set it is.

cheers!
Marcin
 
#36 ·
I'm pretty good with the technical, maybe not so good at providing good news and saving you money! Sorry about that.

Thinking about something.... Most Toyota vehicles have a 5 x 114.3 bolt circle. Most older Subi vehicles (prior to 2015) were 5 x 100. Sure these BRZ wheels will fit?
 
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#37 ·
Well, I was assuming I will need to get new ones anyway. Yes BRZ wheels are 5x100, 7.5 and +48, same center bore at 56.1 - My 08 OBXT is 7 inch wide rim while everything is same specs. I ran some calcs using internet wheel size calculators and is should fit no problem. Offset will be slightly off due to wider rim but it is not much, so it is all good. Now I want to get a wider, summer specific tire so 235 instead of 225. Got winter set on good old steelies :) so I figured why not throw summers on good old OBXT :)
 
#39 ·
Brucey I saw something online recently - which provoked me into looking for more info and - - I found this article. Let me make a preliminary comment about what was happening in the U.S. around the time legislation was passed for the TPMS. You probably were around and aware of the nefarious deeds being committed. A better tracking system was needed to locate vehicles. So the engineers were tasked with designing a system that would not only inform the driver that tires needed airing, but would also help authorities locate vehicles. Voila - the TPMS arrives in 2006. Now read this article and see what YOU think: Tracking Vehicles through Tire Pressure Monitors - Schneier on Security