Tire pressure monitoring systems

[richardr]

We have an Acurite refrigerator temperature monitor in the truck cab which uses 433 MHz and updates every 16 seconds. I wonder if the loss of the tire monitor signal is caused when the 2 signals occur at exactly at the same time.

We put in a warrantee claim about a year ago and received a new monitor set. However we still experienced loss of tire monitor signal at about the same reoccurrence rate. That's why I thought the losses were due to the distance from the monitor to the truck cab.

The loss of signal would be nice to solve, but we can live with it rather than give up the refrigerator temperature monitor. It's just a matter of shutting off the monitor for a few minutes and turning it back on.

[Patandlinda]

Originally Posted by richardr

We have an Acurite refrigerator temperature monitor in the truck cab which uses 433 MHz and updates every 16 seconds. I wonder if the loss of the tire monitor signal is caused when the 2 signals occur at exactly at the same time.

We put in a warrantee claim about a year ago and received a new monitor set. However we still experienced loss of tire monitor signal at about the same reoccurrence rate. That's why I thought the losses were due to the distance from the monitor to the truck cab.

The loss of signal would be nice to solve, but we can live with it rather than give up the refrigerator temperature monitor. It's just a matter of shutting off the monitor for a few minutes and turning it back on.

Richard also have the Acurite refrigerator monitor. We have moniter installed above the refrigerator door in the trailer . You could try to move it and see what happens .Pat

[Patandlinda]

Originally Posted by War Eagle

Just out of curiosity, if another vehicle utilizing the same brand of TPMS passes you, might your monitor temporarily pick up their pressure/temperature transmitter signals? It seems that a company would use only a limited number of frequencies within all their products, so the chance of cross-reading signals could be high - though short lived if/when it does happen. Our wireless rear-view camera monitor will occasionally pick up the camera signal/image from another RV passing by. One time, we picked up an image of us from the rear-view camera of another camper directly in front of us. Freaky!

Never experienced . We have to use highway 5 a lot. Lots of big rigs and RV's . All I can tell you each sensor is numbered for each wheel with it's own code . We were warned the (atomic ) clock was found to give some signal loss. So we just removed it from trailer . Pat

[Patandlinda]

Originally Posted by Brian B-P

That La Crosse WS-6118 is a clock (which is called "Atomic" because it is synchronized to a master atomic clock by receiving a radio signal), but the problem is that it is also an outside temperature thermometer. The outside temperature is transmitted by radio (at 433.92 MHz) to the inside unit, and it is that radio transmitter (unrelated to keeping time) which would cause interference with other low-power radio equipment - such as the tire pressure monitors - which is operating at the same or adjacent frequency.

Thankyou Brian if anyone could give a explanation , your the man ! Pat

[ATHiker]

Originally Posted by richardr

Someone asked about distance between the sensor and display. We have an Escape 21 pulled by a Tundra. We use the TST 507 with non-flow through sensors. We find that we loose the signal for one of the sensors after an average of driving 3 hours. We then restart the system because there is an annoying beep each time the non-working sensor is accessed. I track which sensor we loose, thinking it may be a low battery, but so far it appears to be random. My conclusion is that we are at about the maximum distance these sensors work.

I looked into TST a sensor booster, but they need to be wired into a 12 volt source.

Do you have the monitor mounted on the dash? We have an Escape 21 and tow with a Tundra as well. I'm thinking of mounting the monitor in the rear window.

[richardr]

Originally Posted by ATHiker

Do you have the monitor mounted on the dash? We have an Escape 21 and tow with a Tundra as well. I'm thinking of mounting the monitor in the rear window.

We have it laying on the flat area just in front of the cup holder between the front seats. The problem with it being out of reach while driving is not being able to see what is happening if an alarm goes off.

[Brian B-P]

Originally Posted by War Eagle

Just out of curiosity, if another vehicle utilizing the same brand of TPMS passes you, might your monitor temporarily pick up their pressure/temperature transmitter signals? It seems that a company would use only a limited number of frequencies within all their products, so the chance of cross-reading signals could be high - though short lived if/when it does happen. Our wireless rear-view camera monitor will occasionally pick up the camera signal/image from another RV passing by. One time, we picked up an image of us from the rear-view camera of another camper directly in front of us. Freaky!

There are two approaches to using shared frequencies:

1. blast away and hope that only the desired pair of devices hear each other... if the wrong signal is received, who cares; or,
2. encode all transmissions with identifying information and only accept valid transmissions, acknowledge all communications and retry as required when collisions occur, and shift frequencies (or use other related techniques) if there are too many collision.

Any guesses which one is done by cheap junk that doesn't need to work, and which one is done by modern mobile communications systems including wireless network links? If you're using a Bluetooth headset with your phone and someone walks by with their own device, you don't hear their conversation - that's not just by good luck.

The basic rule of shared frequency use is that you must be prepared to handle whatever anyone else might be transmitting. If someone else transmits on "your" frequency in a format that you normally use, it's your problem to reject it.

[Mike Lewis]

I have a rear view camera system that uses wifi to transmit the image from the rear of my trailer to the tablet I mount in the truck cab, again trying to use the tablet as an all-purpose receiver for data from the trailer. The camera doesn't work very well and I've given up on it. But when I used it I noticed that the video signal would improve greatly whenever a truck passed me on the interstate. I assume the metal panels of the truck were reflecting the wifi signal to the tablet.

I think I've noticed the same effect with the Fobo TPMS; it seems to update when a truck passes. Metal guardrails are also good as reflectors.

[War Eagle]

Originally Posted by Brian B-P

... The basic rule of shared frequency use is that you must be prepared to handle whatever anyone else might be transmitting. If someone else transmits on "your" frequency in a format that you normally use, it's your problem to reject it.

I got my first CB radio in 1971 (still have it, and it still works), back when you were required to have an FCC license to legally transmit, and convention was that everyone politely signed on and off with their licensed call letters/numbers (I still know mine by heart). Then when the FCC dropped the license requirement, Channel 19, "the trucker channel", became the "Wild, Wild West". Talk about being prepared to handle whatever! Now, there's hardly any chatter on a CB. A long haul trucker friend of mine told me that his company now forbids their drivers from even having a CB in the truck cab (company lawyers and risk management people). They give him a company-owned smart phone to communicate with the home base for hauling assignment information and road/weather updates, and they assure him that's all he needs. Otherwise, he's to follow the law and keep his attention on the road.

[Ron in BC]

Originally Posted by Mike Lewis

I have the Fobo system. It uses sensors that screw onto the valve stems and transmit a Bluetooth signal to a small receiver and/or a tablet or cellphone. I don't use the receiver;

I can live with that, but I wish there were a Bluetooth repeater I could mount in the front of the trailer. T

Originally Posted by Mike Lewis

I think I've noticed the same effect with the Fobo TPMS; it seems to update when a truck passes. Metal guardrails are also good as reflectors.

So what is the purpose of the small receiver? Can't it be halfway between the sensors and a device like a tablet?

Ron

[Great Eggstrications]

Originally Posted by Eggscape

Please let us know how yours works if you get one.

I still haven't ordered the Tire Minder TPMS Trailer Solar, but I'm getting pretty close. I am just finishing going through some questions with Todd at Tire Minder - a good guy with, apparently, an abundance of patience when it comes to answering questions. And it's so nice to deal with manufacturers that communicate in real English!

Some questions and Todd's answers:

1 - How long has the product been on the market? I see web availability, but no reviews yet. My wife says I can't order one till some favorable reviews start appearing!

Product has been out since December of last year!

2 - On your web site, I see no discussion regarding valve stem thread material for this particular product. Dissimilar metals are a concern. My trailer has rubber valve stems with brass threads where the sensors would go. Would this be ok?

It only comes with Brass transmitters, However, you could you an Anti-Seize Compound if you have Aluminum valve stems.

3 - What is the refresh frequency, i.e. how often does the monitor display updated data?

Monitor updates every 6 seconds

4 - What does it do if the connection between the sensor and the receiver/monitor is lost? Does it alert, or just quietly continue to display the prior obsolete data?

It will beep, and NOS will appear. If you have the booster you should not receive that message on the screen.

5 - We leave the trailer behind once in a while when heading off-road, and would like to transfer the sensors to our vehicle to monitor the aired-down tires. Will the product operate ok without using the signal booster in this case? Just the separate tow vehicle, no trailer.

Yes, it will work fine, However, you will need to relearn the transmitters.

6 - What is the transmission frequency used with this product?

433mhz


Second questions:

1 – I was hoping to maybe use your Tire Minder TPMS Trailer Solar product for my trailer and concurrently also use the TPMS I already own with the tow vehicle. The unit I already have transmits at 433.92 MHz, so I would be concerned about conflicts between it and the Tire Minder TPMS Trailer Solar product. I know that you really can’t make any guarantees, but should I expect crosstalk problems between the 2 systems? Or would they somehow keep the data flows separate? Any thoughts would be appreciated.

As long as you hook up the booster, there should be no issue.

2 – Can I assume that the display panel on the monitor is smart enough to light up after dark?

Yes, it lights up for nighttime driving.


I'm getting the answers that I wanted, but can anyone think of anything I still should ask about? And any ideas about running the systems concurrently? If everything works ok, I'll just get another one of these Blueskysea TPMS's for 70 bucks and call the deal done.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Using this on our 2017 Honda Accord, which irritatingly only has a general "Low Tire Pressure" idiot light with no indication of which tire is bad, and no temperature data. I'm planning to try using both systems concurrently, given that our tow vehicle has the same marginal idiot light indicator as the Accord.

[tractors1]

Originally Posted by Great Eggstrications

Using this on our 2017 Honda Accord, which irritatingly only has a general "Low Tire Pressure" idiot light with no indication of which tire is bad, and no temperature data.

Older monitoring systems have a sensor in each wheel, which uniquely identifies which tire is low - but the batteries have to be replaced periodically (meaning dismount the tires from the rims.) Around 2010 or so the automakers changed over to counting the pulses from the ABS system as the tires rotate; as long as each tire is generating about the same number of pulses per second, this approach assumes all the tires are equally inflated. If one tire begins to leak, the diameter of the tire will be reduced so the number of ABS pulses will increase compared to the other tires - causing the system to alert you to a low tire pressure somewhere. Advantage is there are no batteries to replace. Indirect Tire Pressure Monitoring Systems Making A Comeback On Some Imports - Tire Review Magazine

[Great Eggstrications]

Yeah - I just sort of figured that both the Accord and 4Runner compared the ABS values across the 4 wheels and lit a general purpose pressure idiot light, but I have since found out that our friends at ScanGauge have a new tweak that pulls the 4Runner's tire pressures off the vehicle's data network and the ScanGauge can be configured to show individual pressures. Still no temps though, and displaying the pressures would use up all 4 of the ScanGauge parameter displays, so would have to toggle between displays or buy a second ScanGauge just for tire pressures - ugh. Wonder what else is lurking around on the data bus. Sure would like oil psi and temp. And front and rear diff and transfer case temps would be pretty entertaining, if perhaps somewhat moot. And how about brake temps and laser ride-height?

[Brian B-P]

TPMS type is not really an "old" versus "new" issue. TPMS appeared in production cars mostly due to the use of run-flat tires, which required (by federal regulations in the U.S. and probably Canada) tire pressure monitoring in vehicles with run-flats. Some people would just drive flat tires to destruction (and possible loss of vehicle control) without an idiot light to tell them not to. Both systems meet this requirement.

Originally Posted by tractors1

Older monitoring systems have a sensor in each wheel, which uniquely identifies which tire is low - but the batteries have to be replaced periodically (meaning dismount the tires from the rims.)

Transmitter-based systems have been around for a long time, and are still used. Charlie, you are listing this as the older system - I don't think it is.

If you want to see actual pressures, this is your only choice. With the increased popularity of computer monitors as instrument panels, offering many pages of information (mostly to impress potential buyers on test drives, but also some real use), this will continue to be popular.

Originally Posted by tractors1

Around 2010 or so the automakers changed over to counting the pulses from the ABS system as the tires rotate; as long as each tire is generating about the same number of pulses per second, this approach assumes all the tires are equally inflated. If one tire begins to leak, the diameter of the tire will be reduced so the number of ABS pulses will increase compared to the other tires - causing the system to alert you to a low tire pressure somewhere. Advantage is there are no batteries to replace.

Speed-based tire pressure loss detection systems have been common for a long time, and are still used - both my 2004 van and 2012 car have them. The article describes this as the older system which has returned.

The lack of batteries is an advantage, but a more significant advantage to many of us is that we can have two more more complete sets of wheels and tires, and not have to either buy extra sets of transmitters or manage synchronizing transmitters with the car at every change (which is usually seasonal).

Originally Posted by tractors1

Indirect Tire Pressure Monitoring Systems Making A Comeback On Some Imports - Tire Review Magazine

One of the weaknesses of older indirect systems is that they may not turn on the warning light if all the tires are underinflated by a similar amount.

No, all speed-based systems (old or new) are fundamentally incapable of detecting a matching loss of pressure in all tires at the same time, unless they are doing a high-precision comparison with an external reference such as GPS or a doppler radar speed measurement... and I'm pretty sure none of them are doing that.

Most of these models have the optional ABS and stability control system.

All passenger vehicles sold in North America have been required to have ABS for several years (it's no longer optional), so they all have wheel speed sensors, including all of the examples in this part of the article. That is one reason for going back to indirect... the speeds are there even on the base model so why add more hardware? Even electronic stability control is now required.


A trailer could be set up with wheel speed sensors at the hubs to run a TPMS system without sensors and transmitters in the wheels... but of course no one will do that on light-duty and recreational trailers.

[ATHiker]

The Tire Minder Trailer Solar unit looks very interesting. I would question how long does it take after starting the unit for it to reflect actual cold tire pressures. To me this would be important to be able to check tire pressure in the morning before leaving camp.

[Great Eggstrications]

Originally Posted by ATHiker

The Tire Minder Trailer Solar unit looks very interesting. I would question how long does it take after starting the unit for it to reflect actual cold tire pressures. To me this would be important to be able to check tire pressure in the morning before leaving camp.

Good question. I don't know the answer, but you can try running it by Todd through the "Contact" option on the Tire Minder web site. I've already pestered him enough, and he would probably like to hear from someone else besides me. Let us know if you get an answer.

Maybe we could all gang up on him and get a discounted group buy going?

[Great Eggstrications]

See the update at

http://www.escapeforum.org/forums/f1...tml#post241788

I don't want to be updating 2 threads at once...

[Mike Lewis]

Originally Posted by Ron in BC

So what is the purpose of the small receiver? Can't it be halfway between the sensors and a device like a tablet?
Ron

Sorry, I didn't see your question earlier. I don't think the small receiver in the Fobo kit is a signal booster or repeater. I assumed it was for people who didn't want to use a cellphone or tablet to receive the tire sensors' signal. It has lights and beeps whenever it doesn't get a good signal, which is why I quit using it-- it beeped all the time and I couldn't find a way to disable the beep.

[Mike G]

I am extremely late to this discussion, but here's my 2 cents anyway: Get TST (Truck Service Technology) tpms. I have been using a TST tpms for about 5 years and it has worked flawlessly. And TST customer service is top notch. I got the trailer too close to a very high concrete curb and broke one sending unit (as well as the valve stem). I called TST and described the condition of the unit and asked if it was repairable, and they said it was not but they would send a replacement free of charge. I replied that it was my fault, not theirs, but the CS guy said it would still be free replacement. After that experience, I see no reason to try any other brand!

I have not needed a booster unit with the (17') trailer, either.

[War Eagle]

Originally Posted by Mike G

I am extremely late to this discussion, but here's my 2 cents anyway: Get TST (Truck Service Technology) tpms. ...

Does the TST have to be plugged in to 12V power to work? Or does it have a rechargeable internal battery? The TST website listed "USB and 12V charging capabilities" (note "charge" as opposed to "power"). I already have too many cables coursing around my dash and console. So if this needs power cabled from an outlet, advantage solar powered unit (at last while the sun is shining).