Service 4wd message...stuck in 4wd!!!

Brock Allen · December 24, 2020

I have a 2014 GMC Sierra 1500 and I was driving yesterday and had the truck in auto 4wd because it was snowing and I got to where I was going and shut the truck off still in 4wd. When I came back it to leave the truck had a "Service 4WD" message. Now the truck will not go out of 4wd and the light on the switch is on but when I turn the knob to 2wd or 4hi and 4lo the light goes off on the knob and I can't hear anything engaging....I figured I would try here first before bringing it to a mechanic in case it was something I could do myself. Any help is much appreciated!

M1ck3y · December 24, 2020

Unless its an electrical glitch I think your transfer case is done.

mjm-1957 · December 24, 2020

There is an updated transfer case control module calibration for that exact problem. Call a GM dealer with your VIN and they can run it and check if it was ever done.

JimCost2014 · December 25, 2020

There was an issue with the 14's and I believe the 15's doing that.

If you left the truck in 4WD while it was cold outside, the trucks would be stuck in that mode when you started it up again.

I think there was a re flash for the transfer cases that fixed the problem.

Brock Allen · December 25, 2020

13 hours ago, Brock Allen said:

I have a 2014 GMC Sierra 1500 and I was driving yesterday and had the truck in auto 4wd because it was snowing and I got to where I was going and shut the truck off still in 4wd. When I came back it to leave the truck had a "Service 4WD" message. Now the truck will not go out of 4wd and the light on the switch is on but when I turn the knob to 2wd or 4hi and 4lo the light goes off on the knob and I can't hear anything engaging....I figured I would try here first before bringing it to a mechanic in case it was something I could do myself. Any help is much appreciated!

I will be calling the dealership Monday. The truck only has 121k. I will give an update when I find out more. Thank you guys.

Brock Allen · December 25, 2020

41 minutes ago, JimCost2014 said:

There was an issue with the 14's and I believe the 15's doing that.

If you left the truck in 4WD while it was cold outside, the trucks would be stuck in that mode when you started it up again.

I think there was a re flash for the transfer cases that fixed the problem.

I will be calling the dealership Monday. I feel like thus should be an issue especially with the truck having 121k miles. I had an 04 before this 14 and it seems like once one thing goes wrong it becomes once thing after another.

JimCost2014 · December 25, 2020

34 minutes ago, Brock Allen said:

I will be calling the dealership Monday. I feel like thus should be an issue especially with the truck having 121k miles. I had an 04 before this 14 and it seems like once one thing goes wrong it becomes once thing after another.

Are you the original owner? Do you know if all of the TSB's were done? There have been quite a few along with recalls.

flyingfool · December 29, 2020

there is an engagement motor that controls a clutch pack inside the t-case, if the throw out lever is stuck it wont be able to shift the t-case, could even be the motor drive is toasted or binding

Edited December 29, 2020 by flyingfool