3 Channel ABS not 4?

[JackLikesTrucks]

What the heck?

I thought the 02 Ranger had 4 wheel ABS. Usually that means 4 channel. That means 4 output lines from the ABS controller. One to each wheel.

The old single channel Rear ABS (RABS) was crap. That was in early 90's?

But when I cracked into the diff today, I see one single exciter ring and then there's only 3 output lines at the ABS system.

So its front x 2 plus RABS. thats 3 channel right. On an 02 Ranger.

How do they get away withsaying its 4 wheel ABS?

[Jspafford]

Rangers have either been Rear ABS, which was only one channel, or 4WABS, which is like you found, seperate for the front wheels but runs off of one sensor for the rear wheels.

If it makes any difference the front will usually always lock up before the rear. Besides, the front are the steering wheels, the rears are just along for the ride. I would much rather have the front seperate than the rear.

[Wicked_Sludge]

the rear tires are connected together by the rear differential. anything that happens to one tire or the other will effect the differential carriers speed. since the ABS sensor reads off of the carrier, the ABS system can determine when either rear tire is locking up. on top of that, since weight transfer moves the majority of the vehicles weight off the rear tires under heavy braking, the rear tires have a tendency to lock up together, eliminating the need for a more complicated set of brake lines and vehicle speed sensors for effective braking.