Is the car not throwing any engine codes? Hard to believe you get all these issues without any codes.

The issue may not be ETM, it could be a crank or cam position sensor starting to fail or even (on your car I believe it may have a cvvt solenoid on the exhaust cam only being an 02).

Neil.

the wirig harness is suspect, a volvo tech said they swap it out with the ETM, seems the gold plating on the plug wears of from unplugging and replugging. I believe they snip the old one off and use butt connectors for the new plug. If you're getting a communication error it wouldn't hurt to do a dr...

the plug that connects to the etm,

check the wiring, i had a bad connector once,very difficult to solve. Does it fail while going over bumps in the road? check all connections while engine is running.

Btw, as you know there is dielectric grease, but there is also electrically conductive grease, to improve conductivity. worth a try.

I had random problems for several years with my 2001 Moondust V70 not idling correctly, rough driving, and having power problems. It ended up being a Variable Valve Timing solenoid sticking. The dealer looked at it twice and couldn't find the problem. The ETM was replaced twice. Eventually it got ba...