Important Information

Subject: 4WD Inoperative or Phantom Shift with Possible DTCs B0770 , B0775 , B0780 , B0785 , or B2725 - kw 226 transfercase PIT3131A - (11/12/2004)

Models: (02 - 05 Chevrolet Trailblazer and Trailblazer EXT) and (02 - 05 GMC Envoy, Envoy XL and Envoy XUV )

The following diagnosis might be helpful if the vehicle exhibits the symptom described.

Condition/Concern:
4WD inoperative or phantom shift with possible DTCs B0770, B0775, B0780, B0785, or B2725 . This concern will be on vehicles equipped with a 226 transfer case.

Recommendation/Instructions:
Remove the transfer case range selector switch from the dash. Inspect the switch case halves and make sure they are fully seated and snapped together. If they are separated or a gap is noticed, snap the case halves together or replace the switch as necessary.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.