TPMS Signal Loss Alerts When Sensors Stop Reporting

[LeeS]

If I unhook my RV from my vehicle and drive away, should the TPMS give me a "lost signal" warning? More importantly, what if one of the sensors dies?

I'm talking to Support for my Tymate TM2 TPMS system and they say it isn't supposed to warn me. That it is supposed to keep displaying the same pressure and temperature. Though the manual mentions a "signal loss alarm" and clearly describes how the main unit will "hide the icon and corresponding data" if is doesn't get a signal from the tires after 8 minutes. At least that's how I read it. Could you please confirm you read the same thing in #9 and #10 in the image below?

I imagine a situation where the battery on the tire sensor dies suddenly or the sensor falls off and I'd like to be notified that I'm not being protected by the TPMS any more!! I would imagine that the main unit should beep at me if it didn't get a signal from the sensor after 10 minutes or an hour or so.

I tested my Tymate TM2 TPMS and I it failed the test:
- I turned the unit on, registered the tire sensors and drove away, but the main unit kept showing that the tires were fine even after many miles and many hours.
- I turned the unit on, registered the tire sensors and removed the battery from a sensor. but I didn't get an alarm

The manual in my Tymate TM2 CLEARLY says it is supposed to have a real "signal loss alarm". Read #9 and #10 in the image from the manual and tell me what you think it says!

 

[LeeS]

Does your TPMS sound an alarm if the main unit stops receiving the sensor data?

What model is it? I want to buy it!

 

[DonTom]

If I unhook my RV from my vehicle and drive away, should the TPMS give me a "lost signal" warning?

No, the monitor needs an update from the sensors. You can drive away from your sensors by a thousand miles, and usually the last PSI readings will still show. A few TPMS monitors may finally time out, but it will take a while. At least many minutes. But they will never detect a loss of signal other than perhaps in that way.

However, if PSI is lost, the wheel sensor puts out a signal instantly as the monitor will then be updated--as long as you're in range--which is not far.

You should get low sensor battery warnings, but this could depend on the TPMS you have. If the PSI numbers do not change while driving, expect a problem.

They do not all work the same way, but I do not know of any that will let you know a signal is lost. The wheel sensors put out nothing most of the time to preserve the sensor battery life. To detect a loss of signal would require significantly more sensor battery drain, as that will have to be a continuous sensor signal to know it has been lost. Not something you should want anyway, just for that reason--unless you want to change all your sensor batteries every few days or so.


-Don- Auburn, CA

 

[John From Detroit]

It appears the monitor in the tow vehicle just hides the trailer if it does not hear from it.

I suspect if it heard from ONE tire, but not the other, for a couple of refresh cycles you'd get "Lost signal" Likewise if one of the car's tires went by by it would "Lost signal" but if both (all) Trailers vanish it just says "Oh, away from trailer) and turns off the trailer displays. .or as Don says puts them "in stasis" (They don't change)

 

[Kirk]

. Read #9 and #10 in the image from the manual and tell me what you think it says!

The way that I read it, those functions are only available when you first set it up so I would take it that you have to set those two functions up when you install it in order to have them operate.

 

[Mark_K5LXP]

You can drive away from your sensors by a thousand miles, and usually the last PSI readings will still show. A few TPMS monitors may finally time out, but it will take a while.

Which drives me nuts. My workaround is to initiate 'auto search' mode which zeroes the display until the sensors update. I had an extended dialog about this with their tech support. They have a fairly convoluted algorithm of if-then about update interval and missed pings. Experimenting with it at home it could go well over an hour before it showed a sensor missing. I installed an external antenna underneath and positioned the repeater such the only RF obstruction is the wheels themselves. I know the max beacon interval is 8 minutes so after a scan I should see all wheels reporting within that time. If I don't, then it's time to go checking. So far this is working OK. I suggested that they could change the color of the PSI reading based on the freshness of the data, then I don't have to start over if I'm wondering about one of them. But, that's just wishful thinking. Along with I would be OK with more pings/data at the expense of some battery life.

What I don't get are the false alarms. A handful of times the thing went off for low or no pressure, when there's no issue. Initiate a search and next ping all is well. Not sure if it's in the receiver/UI code or if it's a weakness in the protocol. Still better than nothing but I would've expected a more refined solution.

Mark B.
Albuquerque, NM

 

[DonTom]

I suggested that they could change the color of the PSI reading based on the freshness of the data

My Tesla, when set to show the tire PSI as I usually have it, shows the the last time it has been updated.

If I do not drive for a week, when I leave it will show the PSI from last week and will says below the psi readings "seven days ago".

Then I drive a quarter mile or so, and that info disappears, meaning I am getting a "now" reading, or in reality perhaps as much as a couple of minutes if no change is detected. The GPS monitor responds to changes it gets from the wheel sensors--and instantly. If the monitor is out of range then there is no change to detect at the monitor and the old psi infomation stays displayed.

IOW, the monitor requires an update for a change to show on the display, like a sudden loss of air will instantly send an update within a few seconds or so. But if the tire is destroyed in such a way that the wheel sensor is 20 yards down the freeway in less than a couple of seconds, there is no signal to detect at the monitor, so all could look normal even with a blowout, if the sensor is then out of range.

-Don- Auburn, CA

 

[DonTom]

What I don't get are the false alarms. A handful of times the thing went off for low or no pressure, when there's no issue.

I have also seen that happen, but not often. It's rather rare. The problem is a TPMS monitor has a cheap microprocessor chip and they can crash or even partially crash, much like any other computer.

A reboot / restart fixes it.

-Don- Auburn, CA

 

[8Muddypaws]

My TPMS (EEZRV) continually scans all programmed tires positions. Each one displays for about 5 seconds before it moves on to the next one. When towing the car there are 10 tires being scanned. If a sensor loses signal the display unit will ‘beep’ when it comes to that position. The worst case with 10 monitored tires would be about 50 seconds. Linking and unlinking the trailer/towed only requires pressing two buttons at the same time.

Unfortunately I don’t hear the beep because of all the years I spent abusing my ears doing all the stuff I loved doing.