4wd selector switch - no lights

[kronin kronins]

Hi guys new here, hoping to get some help for my 09 silverado
 

My 4wd  selector switch has no lights., and have done the following

Replaced selector switch – did not help,

Ground wire under driver door/frame – removed cleaned, did not help

Remove the front diff actuator, bench tested it – it works

Checked 30A fuse – it is ok

Did the reset sequence – keyOn, gear N, turn selector to N wait 30sec – did not help

Getting the following codes: B0780 and 90  4wd low range indicator circuit short to battery, same msg for 2H 4L and N.

Also getting code U0102 lost communication with the transfer case control module – so I thought the TCCM was bad. I swapped with it with a new transfer case module, did not help, selector switch still dark but got a new code saying something about “Calibration not learned” Even if it is not calibrated, why is the selector switch still dark, so I thought the issue is not the TCCM, Or is it??



I am stuck – any help is much appreciated, thx!

[baileyw813]

1. Key in the ACC position 

2. transmission selector to N

3. Turn 4WD selector knob all the way to N and hold it there for 30-ish seconds.

 

you should hear your transfer case engaging/disengaging (learning/calibrating.) Once noises stop, put switch into 2WD or Auto. Put truck back into P, then turn key to off. Turn truck on and see if lights light up and that your switch actually blinks while shifting into 4hi/lo.

 

I had tried everyone’s “fix” but never had the selector switch AND transmission in Neutral (make sure to have foot on brake/emergency brake on.)

 

 

Edited October 14, 2021 by baileyw813
Clarification of when to release selector

[lewdog]

Any luck on that 4x4 fix?