2016 Sierra 4x4 5.3 Code issiues

[Wilseya]

My 2016 5.3 6 spd auto went into limp mode / engine power reduced.  I get 4 codes P279A - Transfer case high range incorrect ratio. (I understand possible trans slip)

 

P0446 Evap vent ( possible gas cap)

 

P16f3. Transmission control module redundant memory performance.  What do I need to do to fix this?

 

P0777Clutch pressure control solenoid stuck on.  How do I Locate this solenoid? Can I replace it without removing the transmission?.

Thank you all in advance for any help.

Ps o did buy a book Haynes Repair manual it is worthless to say the least. 

[Roger Soto]

On 9/21/2020 at 12:19 PM, Wilseya said:

My 2016 5.3 6 spd auto went into limp mode / engine power reduced.  I get 4 codes P279A - Transfer case high range incorrect ratio. (I understand possible trans slip)

 

P0446 Evap vent ( possible gas cap)

 

P16f3. Transmission control module redundant memory performance.  What do I need to do to fix this?

 

P0777Clutch pressure control solenoid stuck on.  How do I Locate this solenoid? Can I replace it without removing the transmission?.

Thank you all in advance for any help.

Ps o did buy a book Haynes Repair manual it is worthless to say the least. 

Did you find a resolution for the P16f3, and P279a? I have a 2016 Silverado with the same issues. Thank you.