Hi,

I recently purchased a 99 Bravada with smart trak. After trying to launch my boat on a muddy boat launch I found out the hard way the AWD was not working. Got the boat and truck out, but now i would like to get the AWD going.

To start out the service AWD light is not on normally. The service awd light is only on with all four wheels off the ground. Only the rear wheels spin and the light comes on after a couple seconds but goes off after any ignition cycle.

Tried to pull DTCs but nothing is there, at least i could not see anything with the scanner i borrow from the parts store. Only some old front wheel speed sensor codes.

I have gone through and checked some fuses and nothing is blown.(Transfer case fuse, 4wd fuse) Are there any others to check?

I changed the encoder motor and nothing obvious changed. The AWD is not working and the rear wheels only spin. The old encoder motor was not in the 12 O clock position when removed like the new one for installation. It was twisted about 30* clockwise for the transfer case stub that the encoder motor twist. (I was going to pull off the new one and return it, but i am not able to hold the transfer case stub in the 30* clockwise direction, it springs back to the neutral 12 o clock position.) Does that mean the old encoder motor is bad?

The transfer case looks pretty new, much cleaner than the rest of the drive train.

I am looking for any tips or maybe a rundown on diagnosing the problem. Are the service AWD codes only able to be pulled by a GM dealer or can a generic scanner pull the codes? Do you think I should recreate the service AWD light and take the car immediately to get scanned? Advise is very much appreciated.

 

You must use a full feature, bi-directional scan tool to access the TCCM for pulling of codes or running tests. You will need to find a shop with a full feature scan tool or go to a dealer to have the codes pulled. If the light comes on, there should be stored codes.

 

Thank you