Necro post? holy crap. Anyway I actually sold the truck summer 2019 and bought a tesla. But while I had the truck (6 years) I used 4WD Lock all the time in the winter when it got rough outside, and on the highway. lots of city driving. Never had any issues with the 4WD system, never had any lights come on and it never felt like it wasn't working.

 

[QUOTE=Duke Reaper22;3498824]4wd lock basically locks all your tires into same rotational speed, if you try to turn more than 45 degrees you can feel it slow down because the fronts spin faster than the rear, and basically will destroy it if you're going too fast. Do NOT confuse this gear with 4wd high or auto or you will spend dearly on repairs.[/QUOTE

2HI,4WD Lock and 4WD LO dash mounted switch is used on the NVG243 part-time transfer case which is a 3 range 2 speed model used on the 4th gen Ram.4WD Lock is the only choice for high range 4wd.It is the same as conventional 4HI and 2HI used in traditional part-time systems and can be engaged while the truck is in motion.4WD LO can only be engaged when the transmission is in neutral,usually when stopped.This is what the OP was inquiring about.To avoid confusion what you are describing is in likely reference to the NVG246 on-demand 4wd system that has 4 ranges.In AUTO the on-demand feature engages 2HI or 4HI depending on road conditions.Otherwise this is still a 2 speed model with 2HI,4HI and 4LO that function the same as the part time transfer case.