V40 complete lose of coms in hot weather
 

Hi hope some one can assist. I’ve read a few comments that seem to fit but no complete answers. My wife’s d2 v40 looses all coms in hot weather after about 30mins of driving. Air con and cruise control are 1st to go. Then slowly all systems seem to shut down no speedo, indicators, gear indication, engine temp, every warning and system issues are raised. Speedo and engine temp along with gear position comes on and off each time they come back I get a boost in power.
Once stopped the engine won’t switch off or won’t restart.
I was once a ford tech but 15years ago so I have a small amount on knowledge. I’ve totally unplugged the CEM and replugged to find that all systems boot back up and all is fine for a bit then all systems go again.
My thinking is that the CEM is over heating in the hot weather as I don’t seem to have the problem on colder / winter days
I’ve not noticed a leak in the car but as the car is black and in the sun is super hot inside it could be causing a condensation issue. I’m not overly convinced with my theory though.
Any help will be appreciated
Graham

CEM overheating is an issue that plagues the P2 platform in hot weather, it wouldn't surprise me if the same happened to these.

When the weather cools down a bit, fire the car up and point a hairdryer at the CEM on low (not for too long!) and see if the symptoms return. A common mod to do on the P2s was to install a cooling fan on the CEM case, not sure if you'd be up for doing this on a newer model though.

So The V40 a couple of weeks ago had all systems fail again except this time a alarm in the dash started sounding, disconnected the CEM and reconnected, all has been ok since with no issues for now. its only a matter of time so ive just dropped off to Volvo for a new CEM to be fitted as this appears to be a common issue.
I cant have this happening to my wife with my kids in the car, it was that or Sell the car which might still happen if the CEM replacement does not work, i did get all codes read and there were alot fingers crossed as i actually like this car.

Also not to above issue, the problem has also occurred in the winter when its been cold, but heater would have been on. and each time ive pulled the cables the CEM has been warm but not really hot.

This isn't a common issue , I'm working on them on a daily basis ,Yours is the first I have heard of. It could be a poor solder connection or a component failure in the cem but that could be difficult to find . A new CEM should cure it. .