JoeFromPA Posted April 13, 2009 Share Posted April 13, 2009 Hey all, Had my TPMS reading come on yesterday when my wife and I were pulling out of our development. Pulled over and did a visual inspection of the tires.....no signs of any of them bulging or terribly underinflated. I figured it was sensing one tire was 25% lower than the others. So I drove to Church and back. Let the tires cool off. Checked them, and my passenger side rear was exactly 25% below the highest (38 PSI highest, the low tire read 28.5 PSI). Topped it off and good to go. So first: yay for it working properly. Second: This stressed to me the downside of having a TPMS sensor that doesn't tell you which wheel, or what your individual tire pressures are....I had no idea if the tire pressure sensor came on because of what it ultimately was, a single low tire, or because I had a slow leak that would've resulted in a more serious problem. Just thought I'd share Joe Link to comment Share on other sites More sharing options...
Mr. Sinister Posted April 13, 2009 Share Posted April 13, 2009 Meh. Not telling me which tire is low doesn't bother me so much. If the light comes on, I know that at a bare minimum one tire needs to be checked and the rest probably should be too. I pretty much only use the system to let me know if there's a leak or sudden damage; pothole, etc. Link to comment Share on other sites More sharing options...
LGT Dave Posted April 13, 2009 Share Posted April 13, 2009 Cool, sometimes it's good to see that the system actually helps once in a while. One thing to note...the TPMS light turns on when it senses one or all tires below a certain pressure (approximately 26-27psi), not when one tire is a certain percentage lower than the rest. See here for more info: http://www.cars101.com/subaru/tiremonitor.html. Link to comment Share on other sites More sharing options...
Bolksey85 Posted April 13, 2009 Share Posted April 13, 2009 Mine came on for the first time when he had the first really bad cold snap back in Dec/Jan. Scared the crap out of me at first because I had never seen it before and then BLAM! there it is. A tech at my dealer told me the system is pretty sensitive which I would say is good and, like Dave stated, comes on with more than enough room to spare. Link to comment Share on other sites More sharing options...
JoeFromPA Posted April 13, 2009 Author Share Posted April 13, 2009 The problem in my case is that it came on at the start of a drive away from home. I pulled over and noticed no overtly low tires. So what do I do now? Either the tire is completely safe and I can fill it up later (what I did) or The tire has a potentially dangerous slow leak which just developed (screw/nail/etc.) and by driving on it further I begin to risk the integrity of the tire and the safety of the vehicle. Unfortunately, I can't tell if it's the latter. Overall, I actually think I'd prefer not to have a TPMS system than to have this system. I'm just being honest, not trying to be facetious. If I get a set of new wheels, I have to buy TPMS sensors for it (expensive) and get it re-calibrated by the dealership every time I swap (also a pain in the butt and costly) or else deal with the TPMS light being on (no point in getting the sensors for the new wheels then). It's an extra part to break. When the system detects something, the warning is ambiguous. Do I pull over now? Am I rapidly losing air? Or did I just hit the threshold on one tire? Meh. Again, just realizing that it's not something I'm happy about having on my car. Joe Link to comment Share on other sites More sharing options...
Mr. Sinister Posted April 13, 2009 Share Posted April 13, 2009 I think it totally depends on how often you check your tire pressures. If your tires don't have a leak, they really shouldn't lose much air, so I check mine every few months or if there's a large temperature change since the last time I checked (30 degree difference or so). So in my case, the light coming on means that there's either a slow leak or a rapid loss of pressure; both indicative of a real problem. With my pressures normally set at 37F/35R, there really are no other scenarios that would explain the 6+ psi drop needed to trigger the light. I agree it's not an ideal system, but it's better than nothing. With regards to TPMS sensor re-registration, you can just buy a second TPMS computer: http://www.legacygt.com/forums/showthread.php?t=108338 Yeah, it was a little expensive in the end, but I don't have to worry about not knowing if I have a leak anymore. Link to comment Share on other sites More sharing options...
JoeFromPA Posted April 14, 2009 Author Share Posted April 14, 2009 Hey Mr. S, In my year of Suby ownership, the tire pressures have been amazingly stable. I have them set to 38 front/36 rear. So during my last oil change and now (when there has been an average temperature swing of around 25-30 degrees), I haven't checked them. I don't even remember the last time I adjusted any of them.....15,000 miles ago many. So yeah, probably just normal air loss in that one tire, while the others remain perfectly stable Joe Link to comment Share on other sites More sharing options...
snow05gtRI Posted April 15, 2009 Share Posted April 15, 2009 Yeah that sensor freaked me out the first time I saw it...I was driving a rental 09 outback in Colorado, and I drove from Denver to Keystone and all of a sudden when I'm in keystone I see this random light pop up on the dash. Looked around the manual and it was no where to be found in the Light Indicators section....then for some reason I remembered that it was a TPMS light (I don't have one in my car being an '05) from reading it on the board somewhere. The next day I had to drive back to Denver and as soon as I got below a certain elevation the light went away. I guess big elevation changes have quite an effect on it. Link to comment Share on other sites More sharing options...
stewartg Posted April 22, 2009 Share Posted April 22, 2009 I have a spec.b so it has the re050's. 1) What is the proper/suggested tire pressure for street driving? 2) Would you adjust the tire pressure up or down for a track day? Currently I think I am at like 28psi all the way around, I know this is far from optimal for any condition. I was thinking of tracking the car Friday so I wanted to make sure I have the proper inflation for the event. Link to comment Share on other sites More sharing options...
captainhook Posted April 22, 2009 Share Posted April 22, 2009 Lucky you, my TPMS system hasn't worked correctly from the first week I bought the car. And EVERYTHING has been replaced: sensors, wires, control module, still malfunctions constantly. Link to comment Share on other sites More sharing options...
apexi Posted April 23, 2009 Share Posted April 23, 2009 I remember my first experience with the subaru tpms, it was about 15 degrees out, and none of my tires were really that low, even after bumping them all up to 34psi the light still didn't go off. I then checked the manual, and it says the car has to be brought back up to 20mph or higher in order for car to check the tpms.. Long story short, i had to go to the dealer who told me, the suggested 32psi or whatever it is, is only valid when its 60f outside, since it was 15f out, the tires had to be bumped up something like 1psi per 10 degrees below 60f. Good dealer experience though, they diagnosed and turned the light off for free. Link to comment Share on other sites More sharing options...
JoeFromPA Posted April 23, 2009 Author Share Posted April 23, 2009 Ok, I'm regretting this thread...see new thread for info Link to comment Share on other sites More sharing options...
captainhook Posted April 23, 2009 Share Posted April 23, 2009 link??? Link to comment Share on other sites More sharing options...
JoeFromPA Posted April 23, 2009 Author Share Posted April 23, 2009 http://www.legacygt.com/forums/showthread.php?t=110841 Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.