2001 Dodge Ram 2500 4x4. Had ABS and brake light on since winter before as I broke the right ABS wire plowing in deep snow. Knew it was getting time for a brake job so I bought a new harness to put in while I was inspecting the brakes. Installed it and lights still on. No biggie, I was waiting to finish a big job in case I had to get all new calipers, knew I needed all new rotors.

Replaced 4 rotors and all calipers except left rear and luckily got to do an outer axle seal in the rear =). The new abs sensor i pulled back out, cleaned the knuckle better and reseated. left abs wire was rubbed by the rotor, so I respliced it. I have no backer plates up front (rusty dodge) so I ziptied both abs cables loosly to the knuckle to keep them away from the rotor. Lights out and all good? No

Now when I'm braking and almost to a stop, it seams my ABS is kicking in. Can hear buzzing in the dash and my brake pedal "pushes" back at me. Intermittent problem. Also sometimes the speedo will spike from anywhere from 20 to 100 mph. Speedo doesn't spike everytime "ABS" kicks in. Speedo works normal at all speeds, no jumping around. I replaced the rear diff sensor and it didn't change a thing. No ABS or brake light on.

I think today I'll unplug a front sensor, and see if this slow speed anomaly still happens. I assume the lights will come back on and disable the ABS. I'd rather drive with no ABS and lights in the dash then this slow speed crap. Any ideas?

 

the Wheel speed signal is dropping out and the abs module thinks this is the wheel locking up...so it activates the abs valves. if you have codes for one of the speed sensors...start there.

If there are no dtc ...you need to record the speed signals from all sensors graph and plot the results...only then will you see the drop out. This requires professsional equipment that can do data recording.