1999 V70 crank no start prior had P 1081 code

[busman]

for past couple of months I had occasionally crank but no start condition, however after couple of try its started, I notice code P 1081. Few days ago eng stalled while idling waiting for green light but its restart -no problem. Following day car park on driveway and wouldn't start at all - cranked well but no avail try to retrieve codes several time, scanner could not communicate showing "error".
Question is where to begin to find the problem...?