Your description is VERY similar to what I am experiencing - sure hope to see a resolution soon - my guess at this piint in time is the ABS Valve assembly but HATE to toss $$ and parts at a possible fix

My DRBIII is not the typical consumer code reader

 

Run the ABS tests it provides. It *might* lend some insight as to what is going on.

 

Ran ALL the DRBIII provided ABS tests - a few ran for as long as 5 minutes
Thought that I might be on to something - no such luck

The DRBIII manual clearly states some tests take as long as 7 minutes while most will take only seconds.

For a reference ran similar tests on my 2002 CG Overland ABS system tests ran for < 60 seconds.

All tests show normal ABS functioning in the RAM, No DTC's stored or present - that said we all know scan tool tests are only a starting point.

Still have not figured out EXACTLY what the DBRIII "ABS Brake Bleed" function actually does to the ABS system - Anyone know? The factory shop manual is of little use when it comes to explaining that function.

Anyone know of typical RAM ABS Failure modes?
Seen on a few other forums that the ABS Valve assembly has been known to cause similar symptoms. Just hate to toss more $$ when I'm not 100% sure.