TPMS what happens

[justscootin]

I had a flat tire on the scooter once as a few of you have and the lights started flashing at 26lbs

What happens when the battery goes dead in the tpm inside the tire, if it is just the dashes I am good with that but if lights start flashing I would be forced to replace the unit (the next time I replace the tire)l don't want to as I am now into my 5th year and it has been pretty accurate till now, but will the new replacement be accurate. I hear other riders say there units are not

 

[Snowdog]

Depending on sensors is always a gamble. Checking with an analog gauge may be better, if done on a regular basis, maybe not. Even if the gauge isn't accurate, they usually will indicate a change in pressure, as will the TPM. So, think of your gauge/TPM as a change indicator first.
The bad news--------, if you don't have a way to calibrate your gauge/TPM, it doesn't mean much, and I don't care how much you paid for it, it can be inaccurate. Again, it can be a test for pressure change, that's good.
I work in an engineering lab where all instruments are calibrated on a regular basis. We have a pressure calibration set up which we use to check pressure gauges, and after a discussion here a few weeks ago I decided to check a few tire gauges.
Most tire gauges are advertised as 1 to 2 % accuracy or up to .8 PSI at 40 PSI. I checked 4 gauges at 40 PSI, one was 3 PSI off, two 2 PSI out, and one was 1 PSI out. All flunked! But , what accuracy do you need? I guess that depends on a lot of factors which could be discussed for a very long post.
What's the easiest way to go? Probably look for a gauge that comes with a Certification of Accuracy from the manufacturer . Then all you have to worry about is whether your gauge is still accurate. How paranoid are you? or, have you dropped your gauge today?

 

[justscootin]

The question was will lights start flashing because the computer can't find the unit inside the tire.

Everything else it seems to have a light come on with the canbus electronics

I am not paranoid about tire pressure, I just don't want to spend $400 (canadian) for the front and back if the units don't tell me the truth. I just like to check quickly when I first leave the house on my street, it has become a convenience
Will I miss the convenience is the question

I think my batteries will be close to end of life as I have heard others getting 3-5 years.

 

[bicyclenut]

Not sure about the BMW sensors but in the automotive industry the battery life of TPMS sensors by manufacturers has been given from 5-12 years. In our auto shop we have just started seeing failing units in the past 2 years due to battery failure. Considering TPMS was mandated in cars in the USA around 2006-2008, and our experience at my shop with battery failures has been more like 7-8 years. Some of the early/current TPMS systems and were/are indirect, not using a battery operated sensor, but using the ABS sensor to detect a low tire, so no absolute data on battery life as there is a variety of methods of TPMS out there. Many sensors shut off when not moving to save battery life, so one variable to battery life can be how much use (moving use) when the battery is being drained by measuring and sending the signal to the control module. Likely this is the case on the BMW as we don't get a sensor reading until the bike is moving at some speed. Since many motorcycles/scooters are not used as much as auto, its possible their life may be longer.

In our shop we can clone most sensors with aftermarket sensors as there are typically only several varieties of sensors out there sending a signal at different MHz and you can clone the sensor to replace an existing sensor. These are considerably less costly that the OEM sensors, 1/2 or 1/3 the cost, but not sure this will be an option on the BMW sensors. I'll have to see if I can take a look at them when I replace the tires this summer.

 

[Snowdog]

The question was will lights start flashing because the computer can't find the unit inside the tire.

Everything else it seems to have a light come on with the canbus electronics

I am not paranoid about tire pressure, I just don't want to spend $400 (canadian) for the front and back if the units don't tell me the truth. I just like to check quickly when I first leave the house on my street, it has become a convenience
Will I miss the convenience is the question

I think my batteries will be close to end of life as I have heard others getting 3-5 years.

Check your pressures with a good gauge, then see what your TPMS say, and make a conversion chart.