now the DTC C0327 is a drive train code to be found , using a scan tool that can read GM drive train codes. this code is 95% of the time the encoder motor NOT the TCCM [ transfer case control module ].... the encoder motor is about $100.... some have found these for $75.. not too hard to do .. but not easy ... the most important thing is do not stress out those wires to it they break easy...make sure loom covers those wires because many have had shorts due to the casting wearing into the wires so loom covering is a must..
THE TRANSFER CASE FLUID SHOULD BE BLUE A TRAC II GM DEALERSHIP FLUID . IF NOT THEN THIS MAYBE THE PROBLEM OR WHY IT DID FAIL.
do not over tighten these drain fill plugs this housing breaks easy its a soft metal ..15ft lbs max...