I wanted to do a poll, but don't see it listed where you can do it.
On my 1998 Ram 1500 with rear ABS only, I have my ABS and brake light come on upon start up and stay on, and other times it goes out as normal.

So question is :
For those that have changed the rear ABS sensor, did it correct the light issue or not ?

 

Yup. For about a year. The error code is for abs/speed sensor. My speedo doesn't work below 30 mph.

 

Well I tried reading it ( ABS/Brake light ) with a Blue Point code reader which will also do ABS codes.
Mine said that the vehicle does not support ABS.
My speedo works fine.
The ABS/brake light has been acting up for a week now and it is a intermiting light.
Start it today and it's on, start it tomorrow and it will be out.

 

What year truck?

 

It's in my 1st post. ( 1998 Ram 1500 )

 

Possibly failing sensor in the rear diff.

 

Strange. Sorry I missed the year. My 98 is a Laramie and ABS was part of the Laramie package, but I would think abs was standard on 98 Rams. I've traced my problem to the abs/speed sensor in the axle. It isn't a big deal so I just ignore the lights. When I was a working technician (primarily on Ford, GMC, Toyota and Nissan trucks) the biggest cause of abs warning lights was a simple dirty contact on the drum/disc. I literally have had so few issues with my Ram, I've never really taken the time to learn too much. But I'd think that one of those two issues is the most likely. I have read here and a few other Chrysler forums that the speed/abs sensor in the axle is quite common.

 

i had my light come on once, and i had to replace a rear wheel cylinder. so i swapped that, bled the brakes and started it up and all was fine, and has been since