once in a blue moon my truck will be in 4 low 4 high, or the neutral light will be in when i start it up in the morning. what gives ? transfer case and transmission are brand new as of 5 months ago. no dash lights are on (for the transmission/transfer case that is) any idea what is going on ?

03 5.3 z71 sierra-stock.

 

DTC's?

 

no idea what that is.

 

Diagnostic Trouble Codes. The transfer case is computer controlled, DTC's give you a starting point for troubleshooting. Otherwise it's all just guessing.