my 1999 dodge ram intermittently fails it's self test at start up and leaves the abs and brake lights...my speedo works with the lights on...it has a rear speed sensor but i was told if the speedo works the sensor is ok...any info would help...

 

There is another sensor in the trans, might be that one as well... (but, I doubt it) Do the lights simply stay on after you start the truck, before you move?

Rear wheel, or four wheel ABS?

 

The sensor on the rear end does not always screw with the speedo. If it's bad or on it's way out.

 

thanks i may try replacing it..it's not too expensive....can the proportioning valve or abs block next to the master cause this?