I have a 99 Dodge Ram 2x4 2500 V8 and a Dodge Dakota 4x4 V8 that are both having the same issue. About a day before my brakes went into the metal, my ABS/Brake light came on. I changed the brakes and rotors on both trucks, since they was both down to the metal. After changing the breaks I tried resetting the computer by unhooking the battery and turning the key in the start position for 1 minute, but it did not help.

I then tried replacing the sensor in the rear differential, but it did not help. I then realized I had 4 wheel ABS and had picked up the 2 wheel ABS sensor. With that I swapped it out at auto-zone. Even though they looked alike, they said it was a difference. Again it did not help.

The ABS/Brake lights are driving me crazy, so I am looking to see if this is something I can rest or what. It just seems weird that both truck have the same issue, when the breaks pads wore out. The really weird thing is it happened within less than a week of each other.

The 2500 does not exhibit this issue, but the Dakota will if you start driving immediately after you start. It almost sounds like the ABS motor engages for a brief second. The faster you are moving the louder it is. This has only happened 5 or 6 times, and it always happens within 15 seconds of starting the truck.

 

Have you checked that there's still brake fluid in the system?

 

The ABS light will come on when the ABS computer is going out or when a sensor is going out.

Since both trucks started having this issue when you changed the brakes, & sensor that is the first place to check.

The brake light will come on if there is not enough fluid but the ABS light indicates an issue on the ABS system - which though it controls whether or not the wheels lock - doesn't control the brakes themselves.

I've had them go out all at once - but never had the issue you describe. I'd guess it is a sensor. The dealer will be able to read the code on the ABS computer. Its totally different from the ECM computer.

Good luck.

 

Another thing about being low on fluid is normally if it is the brake light will be on along with the abs light at least it does on my 98

 

Fluid level is correct on both trucks, that was the first thing I thought of when the lights came on.

I have not been able to find much information on the Front ABS sensors, so I have yet to check on those. I do feel this has something to do with a sensor, since both trucks had the lights come on about 30 miles before the brakes went metal to metal.

I did read about some talking about the floats going bad in the brake fluild holder, but I feel this would be rare for both trucks to go out at the same time.

I still feel it has something to do with the old brakes getting so low, almost like a warning. Just can figure out how to reset or why it did not reset.

I was just hoping someone had a idea before I took it to the shop. I feel its probably something simple, just not sure if its a sensor or a reset of the computer or something like that.

 

If you can try leaving the batt disconnected for like a hr or so. Sometimes they just need longer to reset. I dont have a haynes manual but if someone else does might say something about this.

 

This just happened to me. My speedometer doesn't work below 30~ either. After some research & reading through the haynes manual, its your abs/speed sensor. There are 3, one on each front wheel hub one located on top of your rear diff, a little more on the side that faces the engine. The sensor on the rear diff is the one you need to replace. I believe its around $30 from napa


Here's a video i found

http://www.wonderhowto.com/how-to-re...-truck-244165/


edit: I just reread your post and saw that you replaced the one on your rear diff.

Recheck that you installed the sensor correctly,check your abs fuse, check your wiring going to the sensor on the rear diff, make sure there's nothing screwed up, check the wiring/connection of each of the front sensors, if that doesn't work then replace the front two sensors.