ABS engaging when there is no need

[LeatherNeck1775]

My ABS recently started pulsing when I applied slight braking pressure to the pedal or when letting off the brake pedal and only slight pressure was applied at the conclusion of a braking session. Truck had been in Chicago exposed to much salt and ice over the past 6 years. Changed out all 4 calipers, pads, rotors, and master cylinder to solve corrosion issues. Pulsing of the ABS is still present. Truck brake system is acting like the truck is sliding on ice when there is no ice. It happens at only slight brake pressure and when traveling very slow. Any ideas?

OH, 2001 Dodge 4x4 Diesel.
No ABS light is coming on, brake fluid is topped off, and system is completely blead.

[Tbird100636]

My ABS recently started pulsing when I applied slight braking pressure to the pedal or when letting off the brake pedal and only slight pressure was applied at the conclusion of a braking session. Truck had been in Chicago exposed to much salt and ice over the past 6 years. Changed out all 4 calipers, pads, rotors, and master cylinder to solve corrosion issues. Pulsing of the ABS is still present. Truck brake system is acting like the truck is sliding on ice when there is no ice. It happens at only slight brake pressure and when traveling very slow. Any ideas?

OH, 2001 Dodge 4x4 Diesel.
No ABS light is coming on, brake fluid is topped off, and system is completely blead.
I had a 2002 Ram 3500 4X4 V10 do the exact same thing. I ended up replacing the rear ABS sensor, and both front wheel bearing/hub assemblies, which included the front ABS sensors. The one front sensor I was able to remove revealed dirt and rust in with the sealed bearing's grease. The left side sensor broke off upon removal. So I sold the bearings w/sensors and the rear sensor, truck was fixed. Before this the customer put in a new ABS module which did not fix the issue.

[LeatherNeck1775]

Ok, that is interesting to learn. I must assume that all 4 wheels have an ABS sensor, if this is the case, then they should all be replaced but I would like to know exactly which one is causing me trouble. If I unplug 1, will that allow the system to operate as if NO ABS signals were coming in or will the lack of signal trigger the system to respond to a false negative situation and act like the vehicle is always skidding. Since I don't know how these things are supposed to work, I am making a number of wild assumptions. :eek:

At any rate, thanks for the lead, it gives me a good place to start troubleshooting.

[Tbird100636]

Ok, that is interesting to learn. I must assume that all 4 wheels have an ABS sensor, if this is the case, then they should all be replaced but I would like to know exactly which one is causing me trouble. If I unplug 1, will that allow the system to operate as if NO ABS signals were coming in or will the lack of signal trigger the system to respond to a false negative situation and act like the vehicle is always skidding. Since I don't know how these things are supposed to work, I am making a number of wild assumptions. :eek:

At any rate, thanks for the lead, it gives me a good place to start troubleshooting.
There is only 3 sensors on your truck. The rear sensor, which is on top of the center of the rear diff., and the 2 fronts, in each front wheel hub/bearing assembly, covered by the rotor. If you had an aftermarket scan tool with sensor readouts or the Chrysler DRBIII scan tool you could watch all 3 sensors and see which one reads differently when stopping. Yes, unpluging one would cause the ABS to be disabled, but I'd only recommend this as a temporary solution. These truck are allot better with ABS. Don't unplug the rear one, you won't have a speedometer if you do.