Hey guys fairly new to forum bought my truck about 2 months ago, all systems ckd good when purchased, I have used 4 wheel numerous times so far but yesterday when selecting 4L the light flashes and will not engage, when selecting 4h and 2h it appears normal. Any suggestions would be great, truck has 46k. 2006 silverado crew cab

Were you in neutral going less than 5 mph?

Yes I tried in neutral and park no help just flashes until I select 4h or 2h

Mine has to be in neutral with the foot on the brake to shift into 2L, if not it will just flash.

I'd try it on a slight grade and let the truck roll a wee bit while it's trying to shift.

jb

Thanks for the advice, neutral and a little roll did the trick.