ABS works by looking at the individual tires, and if any tire stops spinning while the others remain in rotation, then the tire that has stopped will get its braking force reduced so that it can resume rotating. The brake pedal will pulsate very quickly when this happens. The braking system will also make a noise corresponding to the pulsating of the pedal.
You disconnected a sensor, this disabled the entire ABS system, and lead you to perhaps replace the wrong component. What you did was to deliberately break the system as a troubleshooting technique. I think the technique is sound, but the results were misread.
When the system detects NO INPUT from one or more sensors, it will shut itself down because it cannot control skidding without input from every sensor in the system. If your brake system is pulsating, and the pulsating comes from the ABS system, then the system is detecting that one or more tires have locked up while the others remain turning. Normally this behavior is associated with aggressive application of the brakes.
There are 3- and 4-channel ABS systems. A 3-channel system looks at the two rear tires in tandem, and if either of them begin to skid, the braking pressure to both rear tires is reduced to stop the skid. The idea is that a rolling tire offers more directiional stability than a skidding one, although a rolling tire may also take longer to come to a stop. Increased stopping distance with driver control is sometimes a better option than an out-of-control skid. The whole stopping distance being longer or shorter is a matter of great debate, but directional stability is generally preffered at any cost. So, if the stopping distance is both shorter and has more control, then there are two benefits of ABS, but if there is increased control at the cost of greater distance, then ABS offers one benefit. Either way, having ABS is generally viewed as being better than not having it. Trucks and vans are more likely to have 3-channel systems than passenger cars, and 4-channel systems are better than 3-channel.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.