I had my 95 4X4 Blazer in the shop to have the posi. Diff. worked on (new bearings and seals) and new rear axle bearings installed. I got a call from the shop and they tell me that there is now an issue with the ABS that has them stumped. After the diff. work (drive shaft was removed) was completed they took it out for a test drive and the ABS pump energized when the brakes were applied on a dry roadway. No codes were set. They returned to their shop and hooked a scan tool up and went for another ride and saw all the ABS sending units sending signals that were within GM spec. Can any of you offer up any ideas as to what is going on, or suggestions as to a fix?

 

Your specific year and model is not listed in this TSB, but the diagnosis & repair procedures are the same:
http://ww2.justanswer.com/uploads/GM...s_bulletin.pdf

 

Thanks for the reply Capt.! The problem turned out to be an intermittent front Lt. ABS sensor that was driving the trucks computer and the tech. crazy. Glad to see they got it squared away.

 

When there's an intermittent drop out in the sensor signal due to a faulty sensor or broken wire, etc, it will set a DTC in memory identifying the affected circuit. When the intermittent condition is caused by the sensor not being close enough to the tone ring, (as the TSB addresses) there are no DTC's in memory. If that's the case, replacing the sensor is usually not necessary. Cleaning the sensor and the hub will take care of the problem.

Glad you got her fixed, and thanks for posting back.