- Joined
- Dec 7, 2012
- Messages
- 3,566
I guess I'm going to put an encoder motor in it?
2005 Suburban, 5.3, 4L60E, NP246 transfer case with push button 4WD and Auto 4WD. Been trying to track down an issue where sometimes you'll start the truck and it will automatically be in Auto 4WD. Probably ever 1 out of 10 starts. More infrequently, you will start it and it'll be in 4 High. My wife, who is the main driver of this, said it went into 4 High by itself while driving the other day.
In March of 2021, I installed a re-manufactured t-case as the one in it was tore up. I swapped over the encoder. After installing, it had a hard time going into 4 High at times... it would just go to Auto 4WD instead of 4 High. I programmed the latest GM calibration for the ATC and it has worked well since.
Transfer case control module/ATC has latest GM calibration. Transfer case itself is in fine working order. No service 4WD message on dash, no codes that I can see (but I should hook up a Tech 2 to check the ATC). Pushing the buttons on the 4WD switch properly cycles through the 4WD modes. About a week ago, I installed a new 4WD switch. In full transparency, I did install a cheap switch. But the problem has persisted. The switch I pulled out of the truck was a Dorman. Could it be two bad switches... sure... but I'd be shocked. Both switches cycle through the 4WD modes Good.
So, I guess I'm down to either TCCM/TC or encoder motor? For encoder options its looks like there's bad and worse for options (Dorman and Cardone reman.) looks like GM discontinued the part.
2005 Suburban, 5.3, 4L60E, NP246 transfer case with push button 4WD and Auto 4WD. Been trying to track down an issue where sometimes you'll start the truck and it will automatically be in Auto 4WD. Probably ever 1 out of 10 starts. More infrequently, you will start it and it'll be in 4 High. My wife, who is the main driver of this, said it went into 4 High by itself while driving the other day.
In March of 2021, I installed a re-manufactured t-case as the one in it was tore up. I swapped over the encoder. After installing, it had a hard time going into 4 High at times... it would just go to Auto 4WD instead of 4 High. I programmed the latest GM calibration for the ATC and it has worked well since.
Transfer case control module/ATC has latest GM calibration. Transfer case itself is in fine working order. No service 4WD message on dash, no codes that I can see (but I should hook up a Tech 2 to check the ATC). Pushing the buttons on the 4WD switch properly cycles through the 4WD modes. About a week ago, I installed a new 4WD switch. In full transparency, I did install a cheap switch. But the problem has persisted. The switch I pulled out of the truck was a Dorman. Could it be two bad switches... sure... but I'd be shocked. Both switches cycle through the 4WD modes Good.
So, I guess I'm down to either TCCM/TC or encoder motor? For encoder options its looks like there's bad and worse for options (Dorman and Cardone reman.) looks like GM discontinued the part.
