Hi, I have a 2004 s60 base non turbo. It has 191,000 but all highway (I put @ 45k a year on it) about a year ago it started stalling periodically at stops and turns. A volvo dealership and a local volvo mechanic haven't been able to figure it out. Now for the past 2 months it has started a whole new list of problems that can't seem to be figured out. I have been to the dealer and 2 different mechanics / specialists and have spent a lot of money. I've had the dash removed , shipped out , rebuilt and reinstalled. I've also had all fuel and fuel related sensors replaced. The problem still remains and now new problems are starting. Besides the stalling , the next wave of problems began as listed: after sitting in stop and go traffic the car has a big bang ( sound and lurches forward ) like as if I hit a big pothole and the wipers kick on. Then I got a brake failure warning and the car shut down. After sitting with the engine off for at least 10 mins the problem seems to go away for a little while. Then the SRS airbag warning came on and stayed on. After having the dash rebuilt the airbag warning went away. The car is still doing the same things but no longer giving out codes. The stalling issue has now become more frequent , the radio stations now change on their own and now the alarm goes off periodically for no reason. This is my 9th volvo & my second 2004 s60 and I've never experienced any of this before this car. I really can use some advice or hear some of your experiences. Thanks, Ken

 

Check all grounds and wiring.

Has the mechanic replaced the Mass Air Flow Sensor?

 

looks like CEM dies or serious CAN bus issue.
What is the weather when that happens more frequently?
Do you have diagnostic error codes from dealer?

 

I have a 2003 Volvo S60 and my radio has done the same thing before. I have replaced my MAF and my MAP sensor and it doesn't seem to do it any more however, just recently my car cut off for no reason and would start but as soon as I put it in gear and push the accelerator it died again. Had it towed to the mechanic and it started right up for him, no service engine light or anything. I picked my car back up and as soon as I got to my road the service engine light came on. Scared to drive it worried I'm gonna break down again.

 

2003 - 2004 CEMs have a serious issue.
This issue starts to reproduce at the hot weather.
Especially when AC is not used. A component is degraded after some time.
So it cannot stand hot temperature anymore.

 

I had the same problem. I would get a warning on the cluster " brake failure stop safely" I would pull over and **** the car off and go to start the car again and it would crank but not start. I would let the car sit for 45 minutes and suddenly it would start again. The problem was intermittent and I never knew when it would happen. So I took out the CEM and ever single relay to check the board for damage. I found nothing on the board so I put it all back in and since I did that I haven't had the issue again. It seems to be a problem with a relay not being tight or perhaps partially plugged in or dirty. However like I said since I pulled the CEM and the relays and put it back in it hasn't had the issue. It's not too difficult just take a picture of the relays before you pull them in order to ensure you replace them exactly how they were. Hopefully it can help someone else and save someone some money.