TPMS failures

Back in 2007 I had a motorhome with the Doran Pressure Pro system. Had sensors on 6 moho tires and 4 toad tires. Had a blowout on the toad and only indication was the frantic waving from the driver in the lane beside me. Had a flat on the inside left rear dual and the only indication from the Pressure Pro was about 10 seconds after I heard the tire flapping. I sold the system.

I'm sure technology has improved since then but I still wouldn't have much faith in them. I check pressures every morning before getting under way and give all tires a "feel" for heat and swift kick at every stop.

Some things you just have to leave to fate. :)

Coolerman wrote:
I searched and found the other 6 page thread on the TST system. That thread is more about the loss of the sensor connection to the monitor and that taking an hour to report to the user. So far no solution to that has been presented. I guess I will hold off and research more before buying.

You're right: There's no user-setting on our TST monitors to shorten the duration for a lost sensor signal alert.

I've tested mine and the monitor gave memory readings for nearly an hour when the monitor was miles out of sensor range.

FWIW, I got an e-mail from PressurePro that stated:

"In the case of a "missed" signal, the miss generally is recognized at the 5 minute update with three dashed lines, - - -, and the tire location that was missed is highlighted. In most cases, the sensor signal will pick up on the next 5 minute update. The longest you could possibly go without being alerted to a "missed" signal is 5 minutes."

I don't have the PressurePro system, so I cannot confirm that.

If anyone has the most recent PP system and is willing to test it for us, alot of us would probably appreciate it.

cameronpatentlaw wrote:

Coolerman wrote:
OK, the MANUAL states, "The SENSORS take a reading for temp and pressure every 6 seconds, but only transmit the LATEST reading every 5 minutes." The Web Site FAQ states, " The readings are sent every two minutes, except if a low pressure, fast pressure change or high temp reading occurs, then it transmits the data instantly. So which is it?

The fast leak mode that detects pressure drops of at least 6 PSI lower than the low pressure setting, transmits that data immediately. That would seem to indicate that it would detect a blowout in semi real time.

I searched and found the other 6 page thread on the TST system. That thread is more about the loss of the sensor connection to the monitor and that taking an hour to report to the user. So far no solution to that has been presented. I guess I will hold off and research more before buying.

Keep in mind that these low voltage devices are optimized to save battery life. It takes a lot of juice to transmit, versus just taking the readings and storing the latest readings in memory (in the device). So if everything remains nominal, then the transmitter is not activated (except every 5 minutes). In other words, each reading has a threshold--and each subsequent reading is checked against the threshold (in a loop). If the latest reading is + or - some window tied to the threshold (e.g., the threshold is 50 psi +/- 5 psi), no "emergency" transmission is made. But, if the latest reading is outside the window (e.g., it senses 40 psi), then the transmitter is activated immediately and the reading is sent to the monitor (which triggers the alarm). If it transmitted the reading to the monitor every 6 seconds, you'd be replacing the battery in the TPMS transmitter every 3 days.

Oops, sorry Coolerman--now I see what you are pointing out! There is a discrepancy between the Manual and Website. I guess the most important thing remains that there be an immediate transmission if there is a reading outside the window.

Coolerman wrote:
OK, the MANUAL states, "The SENSORS take a reading for temp and pressure every 6 seconds, but only transmit the LATEST reading every 5 minutes." The Web Site FAQ states, " The readings are sent every two minutes, except if a low pressure, fast pressure change or high temp reading occurs, then it transmits the data instantly. So which is it?

The fast leak mode that detects pressure drops of at least 6 PSI lower than the low pressure setting, transmits that data immediately. That would seem to indicate that it would detect a blowout in semi real time.

I searched and found the other 6 page thread on the TST system. That thread is more about the loss of the sensor connection to the monitor and that taking an hour to report to the user. So far no solution to that has been presented. I guess I will hold off and research more before buying.

Keep in mind that these low voltage devices are optimized to save battery life. It takes a lot of juice to transmit, versus just taking the readings and storing the latest readings in memory (in the device). So if everything remains nominal, then the transmitter is not activated (except every 5 minutes). In other words, each reading has a threshold--and each subsequent reading is checked against the threshold (in a loop). If the latest reading is + or - some window tied to the threshold (e.g., the threshold is 50 psi +/- 5 psi), no "emergency" transmission is made. But, if the latest reading is outside the window (e.g., it senses 40 psi), then the transmitter is activated immediately and the reading is sent to the monitor (which triggers the alarm). If it transmitted the reading to the monitor every 6 seconds, you'd be replacing the battery in the TPMS transmitter every 3 days.

OK, the MANUAL states, "The SENSORS take a reading for temp and pressure every 6 seconds, but only transmit the LATEST reading every 5 minutes." The Web Site FAQ states, " The readings are sent every two minutes, except if a low pressure, fast pressure change or high temp reading occurs, then it transmits the data instantly. So which is it?

The fast leak mode that detects pressure drops of at least 6 PSI lower than the low pressure setting, transmits that data immediately. That would seem to indicate that it would detect a blowout in semi real time.

I searched and found the other 6 page thread on the TST system. That thread is more about the loss of the sensor connection to the monitor and that taking an hour to report to the user. So far no solution to that has been presented. I guess I will hold off and research more before buying.

RCMAN46 wrote:

Rapid loss of pressure can take as long as 15 seconds. I do not consider 15 seconds as near instant alarm.

If you had a tire blow on a trailer at 60 mph you can travel 1/4 a mile in 15 seconds. Enough time for that tire to cause signicant damage to the trailer.

I do agree with that. And that is why I edited to add that part about watching temps. I do look at the TPMS as a help, but not the end-all-be-all to tire troubles.

Heavy Metal Doctor wrote:

RCMAN46 wrote:

Coolerman wrote:
If a TST system takes an hour to alert you to loss of sensor signal, how long does it take to tell you about a blowout, or loss of pressure? Sounds sort of worthless to me? I'm in the market for a system and that is good to know.

I have a 507 TST system.

Recently I adjusted the pressures on my 10 sensors.

When I removed the sensors 8 of them took about 15 seconds before the receiver alarmed. 2 sensors took about 5 seconds.

Ummm...yeahhh....I'm not sure what TST 507 system other have been using. Maybe older version? I dunno.....But mine works just like RC MAN posted - lost signal = pretty near instant alarm.

.

You have interpreted what I said wrong.

There is loss of signal and rapid loss of pressure. Two different things.

Loss of signal will take at least one hour before the receiver will alarm.

Rapid loss of pressure can take as long as 15 seconds. I do not consider 15 seconds as near instant alarm.

If you had a tire blow on a trailer at 60 mph you can travel 1/4 a mile in 15 seconds. Enough time for that tire to cause signicant damage to the trailer.

RCMAN46 wrote:

Coolerman wrote:
If a TST system takes an hour to alert you to loss of sensor signal, how long does it take to tell you about a blowout, or loss of pressure? Sounds sort of worthless to me? I'm in the market for a system and that is good to know.

I have a 507 TST system.

Recently I adjusted the pressures on my 10 sensors.

When I removed the sensors 8 of them took about 15 seconds before the receiver alarmed. 2 sensors took about 5 seconds.

Ummm...yeahhh....I'm not sure what TST 507 system other have been using. Maybe older version? I dunno.....But mine works just like RC MAN posted - lost signal = pretty near instant alarm.

I also know it will go off fairly fast for pressure alarm. I changed the pressure in my tires and forgot to reset the monitor. It went off as soon as it cycles through all the sensors and got took readings. Maybe 15 / 20 seconds.

And I kept an eye on the temps as more of sign of trouble than air pressure - a low tire gets pretty hot.
Being the first time I have traveled with the system, I watched it pretty closely even checking to see how the hot side on the sun varied from the shadowed / cold side. Not much, but you can see a few degrees difference.

I am downloading the manual for the 507 TST system to see if they tell this information. I want something that alerts me in real time to a blowout/temp change, or change of tire pressure. In 15 seconds, a lot of damage can occur to my camper if a tread separates...

Haven't had one fail, but I have had one SAVE me from a likely blowout on the trailer. Warned me of a low tire, slow leak, checked it, was low, pumped it up, was able to make it to a gas station, pulled a nail out. Without it more than likely I would have suffered a blowout on the trailer, since it lost pressure fast enough that it would have gone flat in about 1 hour.