5 ms·
Most TPM systems work by comparing the difference in wheel speed using the ABS sensors though (lower pressure = lower diameter = higher wheel speed than the oth
by cc439 8y ago
Most TPM systems work by comparing the difference in wheel speed using the ABS sensors though (lower pressure = lower diameter = higher wheel speed than the other 3 wheels = low air pressure warning).
- jstanley 8y agoNice, I didn't know that!
- jhayward 8y agoAh, no. They all work by having an air pressure sensor in the interior of the wheel.
- jsight 8y agoThe comment you're replying to refers to an indirect system: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=44 https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=... I'm not under the impression that indirect is the most common system, as every car that I have owned has used a direct system.
- dsfyu404ed 8y agoMany vehicles are switching to indirect measurement (this is just my impression, I haven't exactly been tracking which years/models use what system). It's certainly cheaper, you only need to write the algorithm once. Early systems mostly used sensors. I'm not sure why they used sensors to begin with since it's not like there's been a big improvement in VR sensors (the thing used to track wheel speed) enabling more accurate measurement. I suspect that the unwieldiness of big engineering organizations plays a role.