There are different types of TPM systems. One type uses the sensors for stability management/traction control/ABS to tell when one wheel is turning at a different rate than the others. The other type actually monitors pressure and sends a wireless signal from the wheel to the dashboard. I think (but don’t know) that they put the sensor in the valve stem.
I’m not surprised to see they have problems with the second type of system. After all, if they put the sensor in the wheel, they have to also have a power source for it, probably a battery. In any case, if the sensors work anything like my digital tire pressure gauge, there has to be some kind of pressure sensitive sensor inside. Wouldn’t there need to be some kind of diaphragm that flexes with pressure changes? Wouldn’t you consider that a moving part?
The first type of system, that makes use of existing stability management/traction control/ABS sensors, seems pretty reliable on cars I’ve driven that have this system.
Well, to be nit-picking about it, all electronics in a car (that matter) either input from a moving part, or ouptput to a moving part.
If it doesn’t influence, or isn’t influenced by, some moving mechanical part…it isn’t doing a whole heck of a lot!
P.S. The way I understand TPMS, it’s a violation of federal law for anybody other than the owner to “disable” it, but once broken, no obligation exists to fix it. Thus, the owner has a perverse incentive to have the TPMS fail right quick!
The sensor batteries last from 5-7 years, and they can’t be replaced. You have to replace the whole sensor. So if the sensors are 5-7 years old and it’s time for tires, you may as well spring for the sensors at the same time.
The sensor is actually below the valve stem, where you can’t see it.
However, fix-a-flat can (and often does) ruin the sensors
All active/direct tire pressure sensor monitor systems (mandated on cars since the 2007 model year) have a battery operated pressure sensor located inside the tire/wheel assembly. The only moving part is the pressure sensor itself. There were systems previously that used wheel speed sensors to indirectly determine if a tire was low by comparing wheel speed to the others. This was troublesome and inaccurate and not nearly sensitive enough to meet federal standards for TPMS systems.
As for my opinions on electronics and reliability, I’m in agreement that electronics are generally far more reliable and durable than mechanical counterparts. At least car-wise.
The point I was trying to make is that electronics can be built reliably. Space may seem like there’s nothing going on there, but your car isn’t exposed to near absolute-zero or lethal amounts of radiation either. My 1994 car is on its original computer(s). I did replace some sensors, which I consider to be wear items based on the age of the car. Truly nothing lasts forever, but I also have a TV from 1990, and have only upgraded my computers due to obsolescence, not them wearing out. I have the same transistor radio I had from when I was a kid, and some items my dad had. If you take a mechanical device and an electronic device, both engineered properly by skilled people, and subject to normal, not abusive conditions, the electronics will almost always outlast something with moving parts.
Well, to be nit-picking about it, all electronics in a car (that matter) either input from a moving part, or ouptput to a moving part.
If it doesn’t influence, or isn’t influenced by, some moving mechanical part…it isn’t doing a whole heck of a lot!
That’s 100% true…but it’s NOT the electronic part that fails…it’s 99.99% of the time the mechanical part that’s failing. It does make systems more complicated…but what’s been PROVEN over the past 3-0+ years…the overall system is much more reliable. If you can replace the function of a mechanical part with an electronic part…you are far better off.
"I’m not surprised to see they have problems with the second type of system.’ @Whitey–I have this system on my 2011 Toyota and have had no problems in 46,000 miles. I replaced the 5
the original tires at 35,000 miles and the TPM sensors were not replaced. On the other hand, my wife, another colleague and I were returning to east central Indiana from St. Paul Minnesota and were driving straight through in a Ford Windstar that our institution provided for the trip. I drew the short straw and had to drive the late shift. We were on a section of I-74 in Illinois in a construction zone and there was only one lane in the direction we were going. This lane had been milled and was quite rough. Apparently, the roughness of the road set off the TMP light. There was no way I could stop, so we kept going until the road straightened out and we reached an exit where we could get off. This vehicle had the first type of TPM system. The owner’s manual was in the glove compartment and we reset the system to turn off the TPM light. The tires seemed fine and the light did not turn on for the rest of the trip. However, rather than get a false reading, I prefer the second type TPM system.
On our 08 Acura, when we had two people in the back seat, the TPM light would go on. Never with the seat empty which was most of the time. I’m sure it was a transmitter issue since it was located in the trunk. The dealer wasn’t too willing to do much about it but offered to have someone drive it around with someone in the back seat. We just traded not long after that. I should have left a note in the car for the next owner.
“The ONLY reason they are discontinued is because the technology has changed and moved on. It’s stupid to keep manufacturing old technology. The computer field has changed more in 10 years then the auto industry has changed in 100 years”.
I often think about technology changes in my dad’s lifetime. He was born in 1904 and died in 2001. In the first half of his life, radio was developed, television was developed, the fluorescent light replaced the incandescent light in public and commercial buildings, mechanical refrigeration replaced the icebox, the computer came into existence, the transistor came about (Bell Labs 1949) and even the conversion of signals from analog to digital and digital to analog had been developed. Automobiles went from open touring cars to enclosed sedans, the automatic transmission was developed, air conditioning was beginning to be installed in automobiles, automobile radios came into existence, and power assisted steering and brakes were available. The telephone system became automated in most locations. In the second half of his life, these developments were improved and refined. My dad’s family had a Model T Ford, my dad’s last car was a 1989 Mercury Sable. Now the Sable was certainly an improvement over the Model T, but both were powered by an internal combustion engine.
I think in the twelve years since my dad died, we have seen some real breakthroughs in technology. The computer has allowed us to augment the internal combustion engine with an electric motor in the case of hybrid vehicles. Satellite communication has led to OnStar. Last week, a friend of ours was on a trip with his wife. He noticed she was having a seizure. OnStar directed him to the nearest hospital. It was determined that his wife, who had been the picture of health, had had a heart attack. Their quick arrival at the hospital saved her life. LED lighting has come into existence. The rear lights on my 2011 Toyota Sienna are LED bulbs and I think it is a question of time until headlights become LED units.
There is initially a high cost for new technology. Ten years ago or so, my wife and I were walking through a store and saw a large, flat screen television. The price was $5500. I now have three flat screen televisions and paid less than $500 for each set. Our console CRT set went to a rummage sale and the CRT sets are no longer manufactured. I’m faced with a problem in the small church I attend. The light fixtures in most of the building are fluorescent with 4 foot T 12 bulbs. T 12 bulbs are being phased out. If I go to T 8 bulbs, I’ll have to replace the magnetic ballast transformers with magnetic ballast transformers. My other option is to replace the T 12 bulbs with 4 foot LED bulbs that don’t need the ballast transformer, but are presently quite expensive. I’m just hoping that the price of the LED bulbs drops enough that when my supply of T 12 bulbs is depleted, I can go the LED route rather than covert to T 8 fluorescent bulbs.
I like antiques and really like old cars, as long as someone else owns them. However, I’m more excited about the technological advances the next ten years will bring.
I think the early 90’s was the golden age of econobox cars. Flawless and reliable fuel injection, easy to shift 5 speed fully sync’d manual transmissions w/hydraulic clutches, strut suspension, rack and pinion power assisted steering, good mpg, easy for the DIY’er to do routine maintenance. All at an affordable price.
Other than the affordable price, most of those features are still available.
hmmm … Ok, so the thing I like best about my early 90’s Corolla that isn’t available now are the bullet-proof bumpers. It has actual rubber-coated bumpers which are completely separate from the body panel. I can bump into a post in the parking lot all day long and not a single sign of damage. No paint chipping of the bumpers. No dents on the bumpers. In 20 years time! And I like the looks of the car with the distinct bumpers too. It looks more like a car rather than what new cars look like now, an egg on wagon wheels.
In terms of features old cars don’t offer much. But, in terms of simplicity old cars offer a lot. Prior to 1968 car motors were very simple. Few vacuum lines, few electronics, and just very basic. Of course they fouled the air, but these motors had power and good driving characteristics. So, I miss simple. Spark, fuel, compression and if the timing was right you had a smooth running motor.
@Triedaq: “I often think about technology changes in my dad’s lifetime.”
I used to think about my grandmother’s lifetime the same way. She lived from 1918 to 2004. When she was a kid, it was rare to see cars where she lived. If someone drove into town, it was news, and everyone knew who it was. When she learned how to drive, she didn’t have to get a learner’s permit or a license.
Eventually progress levels off with maturity, though.
In roughly 55 years, aviation went from kitty hawk to the Boeing 707…500 MPH at 35,000’.
55 more years…and commercial flights are still conducted in pressurized turbine aircraft, going 500 MPH at 35,000’. (Granted faster military and aerospace travel exists but is yet to be commercially viable.)
At sone point, electronics must hit a “sound barrier” of its own, beyond which progress is–at the least–not economically viable. I guess if chips keep getting minitaurized, eventually some wonky quantum physics issues should rear their heads.
I’ve been thinking about how some things were done mechanically in automobiles as opposed to doing them electrically. My 1947 Pontiac had a floor pedal for the starter. Depressing the pedal pushed the pinion gear of the starter into the flywheel and then closed the contacts which provided power directly to the starter. There was no relay or starter solenoid. When Pontiac introduced the GM Hydramatic transmission in its 1948 models, it was necessary to start the car in neutral. There was no “park” position–one was supposed to put the selector in the “reverse” position. Pontiac maintained the same floor pedal starting mechanism, but the Pontiacs equipped with the optional Hydramatic had an addition rod going from the starter pedal to the transmission selector that pushed the selector from whatever position it was in to the neutral position so that the car would not start in gear. Neutral was at the top of the quadrant, followwd by “drive”, “low” and "reverse at the bottom. In 1949, the starter became a pushbutton on the dashboard. A starter solenoid was used and a “neutral switch” was incorporated into the circuit for the models equipped with the optional Hydramatic automatic transmission. This was real progress. However, on the 1949 Pontiacs with the manual transmission, pushing the starter button engaged the starter whether the ignition was in the “on” position or the “off” position.
At sone point, electronics must hit a "sound barrier" of its own,
I’m sure it will…but I don’t think in my lifetime or my kids lifetime or even their kids lifetime. Just when you think we hit a wall…WHAM…something else comes along.
Triedaq
My Dad was born in 1906 and died in 2000. When he was a child they had kerosene lights and wood for cooking and heating. His first car was a brand new 1926 Ford Model T roadster. It cost $304 FOB Denver, CO. My parents never financed a car. They saved money until they could buy it. They would then drive it for about 8 years always carefully maintained. I think it was 1967 before they splurged on a radio. It was a 327 cu in 300 hp Impala. I don’t know what got into them!
faster air travel WAS commercially available to passengers, the cost was pretty high, though. Kinda sad they scrapped the Concorde jet idea, especially with the number of international flights these days.
My Mom drove from 1926 to 1945. When my state required a drivers license. She was intimidated and did not get a license until 1966. I started driving at 13 years old. My dad gave me a 1954 Chevy and taught me how to drive it. I drove it up and down our gravel road. It came in handy as I then drove WW2 surplus Jeeps with trailers while moving irrigation pipes as my Summer job.