Why did this happen?

[Boar-Ral]

Originally Posted by sj-x 500

the sensors are typically located at the hub, on the back side of the hub there will be a type of gold or silver colored ring pressed over the outside of the hub. the pickup is held in the housing on teh rear axle, or in the caliper bracket usually.

the hub rotates, and the "sensor" which is just a magnet, with some thin coper windings around it, picks up on the raising and collapsing magnetic feild, which induces the voltage in the wire, sending a pulse to the ecm along the wires.

do you have a link to how a directional sensor would work?

I had bookmarked a web site when the discussion first started, but I cleared them out yesterday, when doing housecleaning.

I did find another web site though, but this one seems to utilize the Hall Effect, and is different from the one I first found. You can read it here, though.

I also found this web site, where it indicates that the upcoming (or at least upcoming when announced recently) 4Runner will also be able to detect wheel direction, though they are pretty vague on details, apart from the basics that we already know.

While thinking about it further, I can see how you might be able to more easily detect wheel direction with a magnetic system. What if around the ring, you had magnets of increasing strength, and the system could detect if the field was increasing gradually, then sharp dropoff, etc. or decreasing gradually, then sharp rise, etc.? I guess the problem there would be that because the field is translated to voltage in a normal system, increasing voltage means increasing speed. This system I'm proposing would see increasing voltage, just in normal wheel spin, even if the vehicle is not accelerating. Hmm. Maybe there is a way to compensate for that. Maybe two equally-strong magnets on opposite sides of the ring, and the system uses those as "checks." (It would need two sensors on opposite sides of the ring, too, to monitor.) Sorry if I am rambling, and if I am a bit vague. Sometimes I wish I had the intelligence to be an inventor.