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Air pressure sensors

I would like to see (and hear) how many of you think these sensors are reliable?

My 4 runner air pressure sensor has been totally reliable until I switch steel wheels in the winter…then I live with the idiot light until spring. It monitors the spare to a fault.

In my experience, they have been correct about a low tire. They work off of the ABS system by detecting a wheel turning more times than the others. A miss matched set of tires will also trigger the light. I suppose if the tires were all uniformly low, the system wouldn’t trigger the light.


They are reilable, but only to a degree. Do they warn you when you forget to check your tire pressure and it drops 5 PSI? No. Do they point out when there is a big loss of pressure that could cuase an accident? Yes. So even if they are reliable, you still need to check your tire pressure regularly.

the ones that work off the ABS system by measuring differential rotation rates are very reliable. Why? because they are just software and a panel light!

Are they accurate? that is another question! I can’t see how the ABS type can be. The tires could have slightly different diameters, which will cause errors in the readings. Also, they measure differential pressure, so if all 4 tires are low, the system will not detect that.

Re the transponder type that use RF to carry signals from the tires to the computer, don’t know.