Need advice, no traction on slick road whatsoever.

He said diff lock and ECAS, which would seem to correspond with the following...

 

https://www.walmart.com/ip/Tire-Grip-Adhesive-Spray/111600574

Few cans of this might not be a bad idea.

or some of the snow socks
AutoSock Snow Socks Traction Device For 22.5" To 24.5" Wheels

 

If it is a differential/axle lock then they disengage generally in the 25-35 mph range (can be adjusted in truck's programming).

A power divider can be used at pretty much any speed, but obviously doesn't apply in your case if you only have one drive axle.

Neither one should be engaged when the wheels are slipping and some trucks won't engage the axle lock unless the truck is stopped or below 5 mph.

Not the kind of configuration I would have on a truck for going over the hills in the west.

 

So they designed a truck that gives a driver no choice but to park on slick roads. Insightful.

 

Given the quality of some drivers*, that may not be a bad option.


*Nothing should be inferred regarding the abilities of the OP, see your doctor if anger persists after four posts.

 

Well maybe you were hitting ice on the road?

I know the area pretty well and been stuck out there once because of ice.

if this is the case, then maybe not driving it was a good choice.