I've got a '05 4WD Tahoe LS with 190,000 miles. Every now and then when I start the truck, the LED display in the dash says "STABILITY SYS DISABLED" and the 4WD indicator light on the left hand side of the dash says the vehicle is in 4WD Low, after me shutting the vehicle down in 2WD previously. I've tried to switch back into 2WD, but the light just blinks for awhile, then stops. It doesn't feel like the engine is in 4WD, but it's concerning none the less.

The engine also acts very sluggish when this "STABILITY SYS DISABLED" message is displayed. I'd rather not take it to a dealer right away, does anyone have any ideas what could be wrong?

Any help would be greatly appreciated.

 

Make sure your vehicle is in Neutral when trying to return to 2WD from 4WD Low.
I am sure you already now this, but it seems like you are still in Park, from your description.

Sounds like an electrical problem in your tranny.

 

I'm having the same problem. Did you ever find out the cause?

 

Tranny shop "thinks" it the encoder moter. Does that sound lke probable cause?

 

I have experience the same thing , I just had an rebuilt engine put in my Tahoe and the builder did some sloppy work , so
1st thing was Stability Control
2nd was Rough engine
3 rd was constantly running fans

all fixed except stability, which i think is tied in too other problems
Here what i found out
My PCM was loose from engine builder not doing his job , water got in and shorted out PCm wires actually fried them , pulled PCM Cleaned it up replaced 3 pins in Harness and replaced relays and fuses that Blew , about 100 miles into fix Stability Control flashed again on Dash so chasing that down today , really hoping just an Relay that blew , possibly fuse , cheap fix i hope