Service manual

I recently had same error without a subcode.  Put your leads on the battery set terminal, to read the full 220VDC (or thereabouts...196VDC is the total calculated at 12v each battery, but usually sits over 215VDC...when the charger is on, it is around 230VDC).  Then take a Fluoro exposure and check the drop.  Then take a Rad shot and watch the drop.  If it drops way down (mine went down to about 19VDC), replace the battery set.

In addition:

Often you might see a PreCharge Error (subcode) if your batteries are bad...this is what I saw a few years ago (they lasted 3 years) but not this most-recent time, as mentioned above.