How reliable are tire sensors?

[NYlakesider]

Some of those TPMS are useless junk. Example my 16 Tundra! It only says tire pressure on the little yellow light on the dash, you have no clue which one of the 5 (spare) that it is unless its that low and very visible by eye. I plow with my Tundra and I have another set of winter wheels and tires. Go to the garage and have them put on truck. Now none of those wheels/tires has a sensor so ergo it should light up as the dumb system cannot detect 4 wheels (it should show something as 4 tires are in theory very low on air pressure..

Yeah right I can drive 40 miles before the dash light come on. Sometimes it goes out and stays out for days at a time, other times it blinks and then stays lit. Useless junk, fortunately I'm a long time gear head and have been watching my own pressure since 1962.

Now the system on my last 3 Corvettes is great. If a tire is too low or too high a message appears on the DIC (Driver Info Center) it will say something like left rear 22#. If all is well you can monitor all 4 tires as it gives the pressure for each tire on the press of a button.

 

[LVSteve]

If the "low" signal comes on and you're only a pound or so low, that should change almost as soon as you start driving and the tires begin to warm up. If you are experiencing that problem with your SUV, you may want to go to a stiffer tire, or read the tire pressure ratings on the tires and run them with more air in them than the factory 'recommended' setting. Remember the Ford/Firestone fiasco? The tires were rated to run at higher pressures, but Ford recommended people run them at lower pressure to soften the ride. The results were if people let the tires get anywhere below that setting, the tires were too low in pressure and damage to the tire resulted, causing blowouts.

I'm not sure if factory units warn you about high pressure like my aftermarket one does (it also does temps inside tire), but if not, you could also run into an over pressure issue when going from a cold environment to a warm one. For example, if your tires read 3 pounds low when the outside air is 0 degrees, and you add the 3 pounds, then drive to a warmer clime, you could end up with tires over the tire manufacturer's limit. Probably not the end of the world, but it could cause the center of the tire to wear prematurely from over inflation.

Regardless of what any tire pressure monitoring system, you should still have and use a good tire pressure gauge. Notice the emphasis on good. $5 cheap ones aren't worth the money you're saving or the risk you are taking. A good gauge will run at least $20, and get one that's within the range of your tires. A 120LB truck tire gauge won't give you as accurate readings as a 50LB one if your running pressure is 32LB.

In my experience the sensors are not that sensitive. I have them on my Jag and my hands and butt tell me I have low pressures long before any light comes on. When the cold weather came here the pressures went down about 4 PSI, and I can detect that easily.

My SUV does not have sensors, but it is a model well known for wandering if the pressures are at or below the recommended pressures. Indeed, the dealership here got so sick of complaints of "loose steering" and "wanders across the lane" that their mechanics started inflating to 40 PSI every SUV of that vintage. The recommended level is 35. I spotted it immediately and complained because the truck road worse than a Conestoga. That's when they confessed what was going on.

As for the Ford/Firestone debacle, I remember it well because many of the resulting blowouts were taking place in the desert SW during the summer. To me, Firestone were blameless, it was certain folk at Ford who wanted a cushier ride along with poor owner maintenance that resulted in those deaths.

 

[The Big D]

Indirect sensors only.

That's the case for 'indirect' sensors...not all sensors.

Be safe.

It's the rolling circumference of the tire that is sensed, pressure is implied.

 

[windypoint]

Just came back from having a set of studded tires put on my truck. We are having a very icy winter. Normally I have them put on another set of rims. This year they cannot put a set on rims on a vehicle that has TPMS sensors. I have to spend another $300 now for sensors plus rims if I want them on different rims. I elected to just change out the tires on the factory rims. Another "good idea" from the government. They have made my safety more expensive.

 

[Targets Guy]

The sensors on my Forester works just fine. When it has come on the tire was in fact low on pressure and more air took care of the sensor. Wife's Forester works just as well in this regard.

 

[tedog]

Had tire picture on dash, signifying something not right with tires.
Found screw in back left tire. Took to local discounted tire service, which has decent reputation in our small town. Tire repaired, picture on dash gone.

Two days later, drove 100 miles or so, short out of town trip to big city. As I was heading back, tire picture on dash returned. Stopped at discounted tire service on way out of town before back on highway to head home. All tires checked, said they were fine as far as air pressure goes. Still have dash picture. Gentleman returned with a scanner that he held near each tire; all gave the "okay" beep except the one that had been repaired. Their consensus was that the sensor had been knocked off or loosened by the previous fixers; tire was fine and I could make the 90 miles home okay.

Back in my small town, go to original tire shop and asked about repairing the sensor in the tire, as I still have light on dash. Ok, but have to order the part. Nothing done so return home with tire picture on dash still.

Next day I drive-NO picture on dash.
Did it give up? Fix itself? Fall back in place? Do I return to tire shop? What would you do?
Any wisdom appreciated.

My best friend placeses a piece of electrical tape over the check engine and tire pressure lights. Says, out of sight, out of mind.

 

[5Wire]

I got a "package" on four winter tires. Dismount regular tires. Mount winter tires. Balance. Store regular tires. Then in the spring same process to remount regular tires. Same sensors.

 

[joeintexas]

If your tire pressure hasn't dropped and is correct and the warning on the dash is off I wouldn't worry about it since the tech checked it out and found it to be ok.
The wife's car has that on it and it seems to work ok. My old truck has the antique warning system, a steady thump, thump, thump and a strong pull to one side or the other, followed by a stream of colorful language coming from behind the steering wheel.

 

[KnRMachineWorks]

Had tire picture on dash, signifying something not right with tires.
Found screw in back left tire. Took to local discounted tire service, which has decent reputation in our small town. Tire repaired, picture on dash gone.

Two days later, drove 100 miles or so, short out of town trip to big city. As I was heading back, tire picture on dash returned. Stopped at discounted tire service on way out of town before back on highway to head home. All tires checked, said they were fine as far as air pressure goes. Still have dash picture. Gentleman returned with a scanner that he held near each tire; all gave the "okay" beep except the one that had been repaired. Their consensus was that the sensor had been knocked off or loosened by the previous fixers; tire was fine and I could make the 90 miles home okay.

Back in my small town, go to original tire shop and asked about repairing the sensor in the tire, as I still have light on dash. Ok, but have to order the part. Nothing done so return home with tire picture on dash still.

Next day I drive-NO picture on dash.
Did it give up? Fix itself? Fall back in place? Do I return to tire shop? What would you do?
Any wisdom appreciated.

Just a thought, if the new computer systems work similar to the older ones, it may have stored the code for a tire issue in memory and turned the light off. Been several years since my auto tech days but might be worth checking out.

 

[Lt JL]

my sensors are accurate, and operate in real time. They do, however, tell me the problem is in the wrong tire, almost every time. So I check each tire with a gauge, and sure enough, one of them will be low.

 

[Stevens]

Today was our first cold day this year, when I drove out this morning the "tire" warning light was on I checked the pressure with a gauge all were about 5 psi under the correct pressure. I pulled into a station with an air hose and filled each to the correct amount the light went off.
I do like the system I have had the light go on and found low PSI and a nail or other puncture. The light gives enough warning to get to an area safe to take care of the problem.
Except for once when I had a blowout on an overpass.
Steve W

 

[rburg]

In the couple times this has happened to me, it's always the last tire I check that ends up being a little low.

Ummm....well... Lets see, if you lost your wallet, would you keep checking places after you found it? You always stop when you locate your problem. No one keeps checking after they find what they're looking for. Sorry, I couldn't help.

OK, back to the thread. I've seen estimates that the government mandated systems all cost over $1000 per car. Remember when you went to a car dealer and the cars had options? Well, the automated world has taken care of you. You don't get a cholce, they put it on every car and you get to pay full pop for it. Nice the Government thinks so much of you. Makes your life easier, if you want it or not.

 

[BRatliff]

They're NOT!!!!!!
JIM...........................

As another Super Duty owner, I agree 100% Jim. Unless I am towing or carrying an especially heavy load, I run 55psi in my tires. The light has been on almost since the day I drove the truck off the lot. Really wish I could find someone to disable it !!

Best regards, Bob.

 

[Tom S.]

OK, back to the thread. I've seen estimates that the government mandated systems all cost over $1000 per car. Remember when you went to a car dealer and the cars had options? Well, the automated world has taken care of you. You don't get a cholce, they put it on every car and you get to pay full pop for it. Nice the Government thinks so much of you. Makes your life easier, if you want it or not.

I'm not sure where those estimates came from, unless it might have been when they first came out. As we know, economy of scale kicks in and prices rapidly fall on new technology. I mentioned in an earlier post that I added an aftermarket system to my truck. The cost to add sensors to all 7 tires (includes spare), plus the four tires on the trailer was less than half of your quoted figure, and unlike the mandated system, is user adjustable and monitors heat as well as pressure. I suspect the real cost to automakers is more like $200 per vehicle - or less. Of course what cost they decide to pass on to the customer is another story and would vary from manufacturer to manufacturer.

 

[Salty RI]

Remember years ago, the Ford Firestone thing, that's why those sensors were developed, I worked in R&D for that company, and there was nothing wrong with those tires.

 

[Lee in Quartzsite]

Remember years ago, the Ford Firestone thing, that's why those sensors were developed

The Tread Act was created to solve the Ford Explorer/ Firestone blowout problem. The tires would blowout, the vehicle would roll over and many people got killed. Now we have Congress to thank for the little yellow light.

Implementation of the TREAD Act

I just put new tires on my 10 year old truck. I had all new sensors installed at the same time because the original sensors worked well past their expected life expectancy, which is 5-8 years battery life. The new sensors were $50.00 each. They are working great.

 

[ggibson511960]

Accurate???

I've had many vehicles with various forms of TPMS, so I've had a bit of experience. They are NOT accurate, despite proclamations from several posters. Neither are tire gauges. Don't believe me? Compare readings from a handful of gauges taken on the same tire. The best you can hope for is comparative consistency and repeatability. NOBODY calibrates gauges, not even tire shops. It's actually very difficult and requires an expensive bench test instrument. The best you can do is to use a high quality gauge you have cross checked with a few other gauges. TPMS sensors are no different. Most activate at a low pressure set point, arbitrarily set by the manufacturer. There is nothing wrong with having them, save the annoyance of a faulty one that cries wolf. How many of us check our tire pressures every week, or month, without any other indication of trouble like a visibly low tire? I don't, except on my motorcycles where tire pressure has more potential safety impact. IMHO the differential speed sensor types are inherently more reliable. They use the same wheel speed input signal as the ABS. The next most reliable are those that report numerical pressure to a monitor instead of a low pressure alarm. The good news is that tire quality is so high these days that TPMS is seldom needed. Spare tires are omitted from many new cars. TPMS helps to keeps us from total complacency.

 

[Lee in Quartzsite]

I have a very old manual tire gauge that was Made in the USA. My Hyundai Santa Fe shows the pressure in each tire and it reads exactly the same as my old tire gauge. I also have two digital gauges, one an expensive Craftsman, both Made in China, and they have completely different read outs, sometime 5psi or more. Sort of like thermometers...I have 3 outside and they all read different, all MIC.

 

[5Wire]

ggibson511960–IMHO the differential speed sensor types are inherently more reliable. They use the same wheel speed input signal as the ABS.

Yup. I agree.

 

[LVSteve]

The Tread Act was created to solve the Ford Explorer/ Firestone blowout problem. The tires would blowout, the vehicle would roll over and many people got killed.

Actually, the Tread act did not fix the real problem which was Ford specifying 26 PSI for a tyre that Firestone told them needed an absolute minimum of 32 PSI (IIRC). Ford or anybody else could pull the same gag with sensors calibrated for pressures that were too low for the tyre.