I have a 2006 Silverado and went to engage the 4 low today just to ensure it was working. You can hear the solenoids click but the light just flashed for a few seconds and it go back into 2 high. 4 high will engage and auto 4wd will engage but the 4 low just clicks and will not engage. Is this an easy DIY fix or something that I need to take into the shop for repair?

 

try putting it in nuetral then putting it in 4wd low.. in low you have to do this. in 4wd high you do not

 

Do this to let the transfer case shift and then put it in gear and roll forward a little to get the axle to engage.

 

Thanks guys. I tried both methods again and still have the same results that it will not engage. You can hear the solenoids trying to engage when in neutral and the light will just flash while this is happening and then eventually goes back to 2 high. 2 high goes in just fine and the truck runs with no issues. I don't use the 4wd much but every couple of months or so I will cycle through the options and run it just a bit to make sure everything works. This weekend was the first time I have ever had any trouble. I thought maybe the cold had something to do with this but I drove over 150 miles today and tried to engage a couple of times with the same results. Any other thoughts or ideas are more than welcome.