I am happy to report that the DeOxit was a complete fix. After thousands of dollars in parts and hours of digging - that was the solution for me. The car hasn't acted up at all since I sprayed the Deoxit.

oragex wrote:That's great news. Were there any humidity/water traces at the bottom of the ECU box?

No. I didn't see any evidence of water or humidity anywhere.

This is a copy/paste of the solution I posted to a new thread, please respond there: https://www.matthewsvolvosite.com/forums/viewtopic.php?f=9&t=69667&p=368647#p368647 I can hardly believe I'm writing this, but I'm ready to consider my intermittent electrical issue with my 2004 S60 solved. ...

I can hardly believe I'm writing this, but I'm ready to consider my intermittent electrical issue with my 2004 S60 solved. If you've read through the thread, you'll see that I replaced the TCM, CEM, and BCM but continued to experience High Speed CAN crashes in high heat and humidity (above 50% humid...

That's the first thing I tried when I got the tool - I blew some air into the box to clear out dust and used DeOxit on the ECU and TCM connections and reseated them carefully. After I did that it performed very well for 12 days (which is remarkable given the previous situation). I currently believe ...

I went trouble-free for 12 days in weather that I would have expected trouble. Today the car went haywire in 50% humidity and 80° F. @Oragex I can't tell that the hot air evac fan is working - I can't access it while the car is running because it's blocked by the ECU and TCM - I might need to remove...

I held out on sharing this because I didn't want to jump the gun... and even though I'm optimistic, I'm not certain - but I think I am closer to a resolution for my problem. I had planned to send my ECU to XeMODeX, so I ordered the ECU removal tool from ipd. When I got it on May 6, I pulled out the ...

Wow - thanks for the detailed information. I found a youtube series that shows the same process you described. I tested as many points as I could, specifically between the CEM and TCM/ECU but I didn't find anything spurious. There were no signs of corrosion or loose wires ... except for the connecti...

Thanks so much for all of the responses. My intuition had led me to suspect a problem with the VSS (since it kept complaining about faulty signal) or the ECU (ECM) because it is usually the first module to fault. Yesterday I went digging around and pulled out the speed sensors from the transmission ...

Kind of bummed that no one has shared any ideas.. but i did go ahead an purchase a new Speed Sensor and I've emailed XeMODeX with some questions about the ECM.