I have a scanner that will read transfer case codes, autozone or other basic scanners cant read the t-case. If you want to drive out to Denton you can use it.

 

That's what I thought, but I wasn't sure. Since I have my own scantool, I've never seen theirs.

 

Come by the shop one day.. Or PM me, I have a new number.

 

I'm having the same f***g problem with my '05 Silverado. Service 4WD light on and my lights work on my buttons sometimes. It seems that when I turn the truck off and back on it will shift into 4wd until the service light comes on then everything is locked. I have replaced the buttons but didn't help. Dealer says the encoder is $400 and sensor is $80. So far I'm learning to live with it. My old '91 Z71 had a shift lever and NEVER had a problem. I guess they had to change it , not making enough money on repaires.

 

yeah, I've been having the same MF'in issues with autotrac in my 02 Sierra. Sometimes works for a split second on cold start up, but not after... tried replacing encoder and switch too, but NO luck. It just WILL NOT engage anything 4wd. even tried sittin down under while a friend engaged and I lightly tapped with a mallett.
I vaguely remember reading a few years ago about what I thought was a cable pull actuator... but can't remember the details or brand name, or if it was compatible with our NBS's or not...



....oh, and slightly related, it's ironic that my 01 Silverado which is lowered and 4wd but never goes offroad or sees bad weather performs just the exact opposite!!? The autotrac in that truck engages 4hi or 4lo just fine, but will then trigger “Service 4wd“ light and refuse to disengage until I restart it!!?? Almost wish it was the other way around with the two trucks.

 

This resolution worries me, my 04 just started acting up. Service 4 wheel drive message, and sometimes it starts in 4lo. Today the lights went completely out on the switches but its in 2wd. Guess I will have the codes ran at the dealership or is there a different option?

 

Ive read that there are some switches with bad solder joints, but since you replaced yours i cant see that bieng it.

Any one around you with another 4x4 switch you could try?

Or i guess a scantool is the next step like you thought.

This suks, good luck.

 

Mines still broke too, and it won't engage at all, but the service 4wd light hasn't came on since I replaced everything so I'm stumped.

 

First step should always be check the codes. If you've thrown all the parts at it, it most likely needs to be reflashed or you have an open/shorted circuit somewhere. Most of these are switch or encoder motor sensor issues but there are tsbs on connectors affected by moisture.

 

I think moisture does play a role , when it is real humid or raining it acts up more than when it is dry. I had my codes scanned and they could'nt find any, even when the service 4wd light was on. I did replace the switch but didn't help. Who has the transfer case scanner other than a dealer who will charge $85 just to scan.