Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
the most common problem woud be the transfer cae acuator[encoder]it may need to be replaced
please ACCEPT my answer so I can get credit for my work.i don't receive commission unless you do ..i'm not always going to be giving you good news,so please dont let this stand in the way of you accepting my answer.it does not cost you more money.we will still be able to communicate.. Bonuses and positive feedback are appreciated!if you are not satisfied with my answer,please do not leave bad feed back,i will gladly opt out and let another expert handle the question.PLEASE ASK IF YOU NEED MORE HELP
Bulletin No.: 04-04-21-004
Date: December 16, 2004
with Four-Wheel Drive (4WD)
Some customers may comment that the Service 4WD light is on, the 4WD system is inoperative or the 4WD switch indicator lights are blinking.
Technicians may find DTC C0327 in the Transfer Case Control Module (TCCM). This would indicate an encoder sensor malfunction.
It is also possible that the module may be in a mode that will not allow any shifts or updates for the software or calibrations. If this occurs, the TREC fuse (in the engine compartment) must be pulled and reinstalled after 30 seconds.
This should allow further operation and service of the system. If a C0550 code is found, this is an unrelated concern and SI diagnostics should be followed for this concern.
Tighten all four bolts to 13.5 to 17.6 N.m (10 to 13 lb-ft).
Parts are currently available from GMSPO.