TPMS

[Thumper]

"Tire Pressure Management System" - The little yellow idiot light on your dash board that's supposed to come on when you have a tire that's under inflated (or all the way flat, like you couldn't notice that.) I call it "Pressures for Idiots" and don't much care for it. I've always checked all pressures if not weekly then a couple times a month, and whenever I notice any handling issues. So I don't need it. So far most of my experience has been false alarms. And with false alarms, once you start ignoring the alarm, you're almost worse off. Having to replace them (expensive) if they break when replacing tires, recalibrating/reprogramming them is a hassle. I just use my trusty gauge and add air as necessary.

In another thread, I mentioned we have stable full of rentals for the time being. As I was picking up my Subaru rental at the body shop we were going over the car looking for dents and whatnot, the tech said, "Oh that tire warning light is on but don't worry about that. We haven't had time to take it in and have it fixed." So I got home, found the recommended pressures printed on the door jamb (Subaru often has differential pressures with the fronts higher than the rears) and checked. The fronts were a good 8 psi low and the rears were 5-6 low. I corrected then and the next morning the light went out. The system was functioning perfectly and the human factor still screwed it up. I expect that from the general public, but not from professionals in the automotive industry. So I still stand by my statement that the entire system is a useless expense. Your mileage may vary.

[squ1d]

Would you have checked your tires if they hadn't said anything about the light ?

[Thumper]

Probably not. But not sure. Since I was going to be driving it for at least a week, I planned on checking most everything: Oil, coolant, wiper fluid. I'd have noticed the light and probably checked pressures. Without the light, only having the car for a week, I probably would NOT have checked the pressures, and they did not look low being short 8 PSI. Like I said, in this instance the system tried to work perfectly: it was announcing a minor problem before it became major, that otherwise was unnoticeable. But the tech tried to defeat it.

[vendic]

Some gauges and warning lights are total crap.
Tire pressure warning light?
Not for me. Personally I think everyone should know how to do very basic checks for themselves as part of the license process. More like in some parts of Europe. You should be able to check tires for pressure and wear as well as check the brake pads. Many modern cars have an easy to see from the outside visual indicator of brake wear. The other thing to know is how to check the wheel nuts (lug nuts). Do that and you can be pretty confident your car will work as expected on dry and wet roads and give you the ability to stop. That's pretty much the most common cause of maintenance induced motor accidents sorted right there. Anymore than that and it's self defeating.
Ever seen a car with the engine seized, smoke and steam coming from it?
I have. They had a temperature gauge that they never checked while driving...

[geonuc]

My Subaru BRZ apparently has decided that the tires don't like cold weather. The tire light is illuminated pretty much all winter long. And the tires are fine.

Coincidentally, yesterday I was following a car whose right rear tire was almost completely flat. The rubber was bulging out a lot and I think it had maybe one inch from rim to ground. I expected a blowout at any moment. Yet the driver apparently had no idea because she was driving like an asshole - tailgating, speeding (this was city traffic, so her speeding didn't get her anywhere and I caught up to her at red lights/stop signs a few times, thus was able to observe the tire for a while). I thought about trying warn her of the tire's condition but didn't get the chance. She could have used a TPMS.

[vendic]

TPMS!
We don't need no stinking TPMS!

[SciFiFisher]

My TPMS has worked fairly reliably. It serves to remind me to check the tire pressure when things are out of whack. I usually make sure to have the tires rotated and the pressure checked every time I have the oil changed. I won't discuss how long it took me to realize what that little icon meant on the first car we bought that had it.

[Swift]

I don't mind the TPMS, mostly because I haven't had problems with false positives.

I had the "check engine light". It covers a range of problems from false alarm, through minor, up to big trouble. And unless you go into a shop or garage and have someone talk to the computer, you don't even know. And I've had plenty of false positives over the years that only get me worked up for nothing.

Instead of the worthless "check engine" why doesn't it display a 3 number code on the dash, and you could look that up in the owner's manual or on-line and just know what the problem is?

[vendic]

Instead of the worthless "check engine" why doesn't it display a 3 number code on the dash, and you could look that up in the owner's manual or on-line and just know what the problem is?

Go buy an OBDII bluetooth adaptor. Plug it in and it tells you everything on your phone. Cost about $20, software called Torque is about $5. It also lets you reset codes. Cheaper than a service call.

[Swift]

Instead of the worthless "check engine" why doesn't it display a 3 number code on the dash, and you could look that up in the owner's manual or on-line and just know what the problem is?

Go buy an OBDII bluetooth adaptor. Plug it in and it tells you everything on your phone. Cost about $20, software called Torque is about $5. It also lets you reset codes. Cheaper than a service call.

Cool. I will have to check that out

[Thumper]

Mrs. T's Nissan had false positive's alot, especially in colder weather, especially when the car was loaded. I'd put the gauge on them and even bump them up a couple PSI above spec. Indicator would be on during the weekend, with the three of us packed up for volleyball tourneys. When it was just Mrs. T commuting during the week, it would go off. That problem has seemed to have gone away with new tires and one new sensor.

The car driving around oblivious to having a flat is basically my point. There's a good chance that indicator was on and had been on for some time, maybe the entire time she owned the car. And she just ignores it. If you're not going to do a walk around, if you're not going to throw a gauge on the tires once in a while, if you can't notice the handling behavior of your vehicle when you have an underinflated tire, you're probably not going to leap into action when the TPMS indicator light comes on. Especially when it's just one light of many illuminating the dash. I get into cars all the time with the Check Engine Light, 2 SRS warning lights (air bags) and the Brake light on.

I love the Brake light indicator. I picked up a friend's car at the airport. She told me, "the Brake light will be on but don't worry about it. The parking brake was not applied, it was just a mistake." When I got home, I opened the hood, found the brake fluid reservoir to almost empty, topped it off, and the indicator went out.

[vendic]

Yeah, the things I've seen people do with cars scares the crap out of me at times.


Swift, if you have any questions with the OBDII adapter just let me know. I have one on our car and we use it regularly. I set it up to read instantaneous fuel usage on long trips because our car doesn't have one. The software allows you to make your own dashboard of what gauges you want and there are hundreds of parameters to choose from if you want to go that far. Typically our car gets about 18-21mpg on average. Using the gauge on my last trip I took that up to over 27mpg by changing driving style alone. I could have gotten more but that required slowing down on I-95 to what I thought was too slow for safety.

A friend had issues with a safety light coming on and putting his car in limp mode regularly. They never found the problem but charged about $200 a hit to reset it. I was there when it happened and got him an OBDII diagnostics setup from an auto store (they are more expensive there). We reset it and he was ecstatic. Every time the thing did it again it was a 30 second fix.
It's very highly recommended.