Getting codes on My mom's 2004 Tahoe Z71

[ChevyZs76]

Codes that she gets are...
P2771
U1000
C0327
The previous owner replaced the 4WD switch on the dash. The switch briefly lights up on the 2wd portion of the switch...then it goes out. Just trying to see if others have had this issue and how they fixed it. Or if there are any common fixes for this. Thank you in advance

 

[SLCHOE]

Transfer case encoder motor if the motor doesn't even try to shift but more than likely the encoder motor position sensor inside of it. Many threads about it. Basically, if you have the skills, drop out the encoder motor, open it up and try installing the sensor yourself for the cheap fix. Encoder motors are not cheap.



http://www.dormanproducts.com/itemdetail.aspx?ProductID=45401&SEName=600-120

http://www.amazon.com/Dorman-600-120-Transfer-Motor-Encoder/dp/B004GBAPC2