Problem solved by Volvo agents, diagnostic showed solenoid or sensor problems in i-shift, the top of transmission was removed and ribbon cable and...
I have a VOLVO D13 I SHIFT WITH 600000 MILES. RECENTLY the TRUCK STARTED TO completely LOSE POWER while driving along the road AND JERKS...
My truck is doing exactly what you have described, I have had the Volvo tech s run diagnostics twice and it’s indicating problem in I-shift...