REMOVAL - 4X4
Disconnect the ABS wheel speed sensor wire from under the hood.
Raise and support the vehicle.
Remove the tire and wheel assembly.
Remove the sensor wire from the clips on the brake hose.
Remove the brake caliper. (Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/DISC BRAKE CALIPERS - REMOVAL).
Remove the disc brake rotor and adapter. (Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/ROTORS - REMOVAL).
Bend the tab on the dust shield upwards to allow access to the bolt.
Remove the bolt attaching the sensor to the hub bearing. (WHEEL SPEED SENSOR - 4X4)
Remove the sensor wire.

 

just my 2 cents here but i had my ABS and BRAKE light on for a while.... my cruise didn't work either so in the process of fixing my cruise control i found a vacuum leak. when i fixed that my ABS and BRAKE lights went out. don't know if this helps or not... probably not but thats all i got.

 

Mine turned on the other day and took to a family mec. he said its the hub assembly, he replaced the hub and the problem was gone. truck is 2003 dodge ram diesel.

 

i dont think thats the problem in my case, but how can you tell if the hubs are bad? I hear something rattling when I hit a bump but if I jack up the car and wiggle the tire back and forth it doesnt move at all. How can I tell if my hubs are bad 175k miles, I got the truck used so I dont know if they were replaced previously?

 

Without actually driving it with the scanner hooked up and watching the wheel speed sensor speeds, it is all a crap shoot. The sensors are replaceable on your truck. If I were to guess, that's a VERY good place to start going by the codes you had. I've seen brgs go bad and not turn the light on, and I've seen sensors go bad and the brgs be fine. The later model 3rd gens do not have a replaceable sensor. They are serviced in the brg.

 

Im just about to order the sensors and I noticed that sometime when I hit bumps the lights go off. I followed the sensor and it looks like theres a connector that it runs into at the top of the wheel well.

My question is, if both sensors are showing open with the scanner, does the two connectors at the top of each wheel well connect together? (like a Y before it goes to the brake module?) Im thinking that this cable (after the sensors, between the top of the wheel well and the pcm might be loose)

Where does it go after the wheel well? so I can get under there and wiggle it.

Do you think im close to something or chasing a lost cause?

 

The connectors in the wheel well go into a larger harness, and from there go to the drivers side near the firewll. That is where the CAB (controller antilock brake) module is. Yeah, defiantely wiggle all the wires, but I'm still putting my money on the hub brgs.

 

My 97 has 4 wheel ABS and the most expensive part (the hydraulic control unit) when bad. When you start it up the thing runs a self test and exercises the dump valves and pump motor all in a few microseconds. The dealer said it was most likely clogged up because the brake fluid was contaminated. Try changing the brake fluid with dot 3 only, it does absorb water more but I guess that's the point, the ABS stuff is built with very tight tolerances, expensive as well.

 

I went out there today fooling around with it a little more and found that the drivers side abs sensor (under the split loom) the wire had been completely cut. I soldered it back for now and reset the battery, and drove it a mile down the street but the light is still on. Maybe it takes a while to reset, im not sure if that sensor wire would be enough for it to blow a fuse, im thinking the sensor would just report open all the time.

that still doesnt explain why both of the sensors are reporting open circuit
ill put some miles on it and see if it goes away once the pcm builds some history

 

On a trip to Phoenix from Puerto Vallarta Mexico I experienced ABS and Brake Light issues. They would come on and remain on. Turning off the ignition would reset the lights only for a few miles then they would again come on. I had previously replaced rear sensor and the right front hub with new sensor a month before the trip. In Phoenix a Midas brake shop checked sensors again and ran a scanner tool on the truck and it indicated "open relay". To Midas this meant I would have to make a trip to the dealers. $600 later the ABS controller was replaced and problem was fixed.

 

was it both the front left and the right abs sensors showing open? cause thats the problem im having.

i though the abs controller was much more expensive...like in the neighborhood of 2500?

i ordered the sensors but for some reason the are taking a really long time to get here. the dealer says they should be here today

 

I noticed you said a couple times that when you hit a bump the lights go off and on. We have a Bravada that did that. It was a broken lead wire from the hub to the first weatherpack connector mounted on the frame. Every time it breaks it throws the ABS light. It got to the point that when the light comes on I know it's a broken pigtail wire. I've probably repaired the break 4 or 5 times now, each time in a different spot. Anyways, you may have a broken wire somewhere. In my case, it was easy to find...the molded outer casing on the wire broke with the inner wires. I've been pretty lucky for a couple months now because I think I've made enough repairs to it that they've lengthened the wire so it has enough slack to not be pulled and break as the suspension moves. The down side is if I want to replace the wire to fix the problem, I have to replace the hub and I refuse to replace a hub-bearing assembly to simply fix a wire. I would run/grap/shake the wires from the sensors to the abs computer while someone is in the truck watching the for the light to go off/on. I would also take each connector and unplug it and plug it back together then run the wires. When you said a bump made it go off and on, my first thought was something wore through the wire or the wire broke like our Bravada did.

 

I just got done swapping the sensors what a pain they are to remove but after I got it done I reset the battery and drove down the road. Both ABS and BRAKE lights are off after replacing both abs sensors.

I wanted to take the time to thank everyone that helped, especially vzdude for putting up with my stupid questions Thanks once again for helping!

 

Glad you got it taken care of! Good luck!