Bravada AWD kicking in, crow hop

[Easyman]

Hello, first time post. I have a 2003 Bravada that is going into AWD intermittantly. I have been trying to understand what triggers it for a few days now but no luck. I changed the ATC case oil in hopes that would clear things up.

I found a few posts about checking or changing the encoder but was really looking for a description of how it works. For example, can you manually disable it? I saw a reference to removing Fuse #8 (ATC) but that didn't do it but maybe you need to do this when it is not in AWD?

I also ran across a TB #02-04-21-008A desribing a few scenarios. Is it possible to remove the ATC encoder and motor and enable/disable AWD by mechanically turning the splines in the ATC where the motor/encoder connects?

Any help is appreciated.

 

[The_Roadie]

How many miles on it, and have you been changing the transfer case fluid with the specific GM AutoTrac II required every 50K? If not, your clutches may be toast and then the position of the encoder motor doesn't matter. When you drained the fluid, how much came out and what was its condition? Do you have maintenance records if you aren't the first owner?

Without a dealer or high end mechanic with a Tech II scan tool or equivalent, you can't command the encoder motor to go to minimum AWD position but it should certainly be there on ignition start. If you catch it on a good day, then pull the fuse to freeze it in position. But if the clutches are bad, that won't help. Yes, you can pull the motor and rotate the shaft, but I'm not certain what position (CW or CCW) is best for the NVG126 transfer case.

For a bit of reading on the NP226 (also known as NVG226) case with the low range, go to our sister offroad site's tech articles section. Here's a link: Offroadtb.com Transfer Case Operation: NVG 226 (NP8)

 

[Easyman]

Thanks for the reply! Yes, I have been changing fluid regularly. Currently has around 120,000.

Unfortunately I spilled a quite a bit when the drain plug came out so not really sure.

I'll look at your sister site and read a bit. I think I'll try to start it and pull the fuse prior to moving it just to see if that may give me some clues.

May try pulling the encoder moder this weekend.

I saw a reference to a TCCM fuse on another post. Is that the same fuse as the ATC fuse?

 

[The_Roadie]

I saw a reference to a TCCM fuse on another post. Is that the same fuse as the ATC fuse?

Yep.