98 Yukon 4wd

[Jazz]

Hey guys,

I had originally posted something in the general forum and this would probably be a better place for it. Plus, I have additional info so Im reposting.

I could really use a hand with the 4wd.

It's a 98 Yukon with the 4 button 4wd (with the auto-4wd)

I'm getting the 4 lights at start up. And when I hit 4wd HI I can hear the actuator engaging and it stays in 4hi. If I hit 4-lo the light for lo will blink for 5 seconds and then go back to 4Hi. There are no clunks or anything. No sound.

When in 4Hi i can turn the front driveshaft manually, which makes me think it's not really in 4hi even though the button is solid.

I tried the diag wire in the OBD #13 and ground- I get no error codes. Is that the right slot on the OBD for a 98?

Any help would be appreciated. Thanks!

 

[ss444]

Newbie here,
Was told to put trans in neutral, hit 4-low, light goes on, shift trans
to 3rd.
Ken

 

[Jazz]

Yup. I was in neutral when attempting the Lo.. s

 

[Jazz]

More info..

I replaced the 4wd push buttons and the short to that is gone. There was some damage to the back of the unit somehow.

I put it on jack stands and put it in 4hi. It appeared to work, but only the rear wheels spin.

So the button stays lit on 4hi but it doesn't actually go into 4wd.

That might help in the diag bit of it, and I tried to get codes again- nothing.

At this point I'm thinking it's a TCCM or a Transfer Case motor. Anyone?