I have a 2004 S60 with 205,000 miles on it that I love. For quite some time, I have had intermittent issues, that all seem similar, but may have nothing to do with each other, and currently having a drive-ability issue that is a mystery to my Volvo specialist technician. Right now, what is happening is that I will be driving normally, and usually after a noticeably hard or weird shift (automatic trans), the car goes into limp home mode, the Brake and ABS lights come on, a warning that says "Brake failure, stop safely" comes up, The odometer and trip meter stop working, along with all gauges except the gas gauge, and there is no AC. I stop, turn the car off and when I turn it back on, whether it has been 30 seconds or overnight, it runs perfectly fine, everything on the dash works and instead of the brake failure message, I have one that says "transmission service required". The latest time I took it in for the codes to be read after this all happened, the codes were: CEM-1A61 Communication with TCM control module signal missing (22 counters); CEM-E000 Control module communication faulty communication (21 counters); ECM-510F Vehicle speed signal - faulty signal (19 counters); ECM-922C Cruise Control - Communication fault (19 counters). Any ideas? Anyone? I'm going crazy over this!

 

Just a long shot but I think you need some kind of transmission work.

 

There's a CAN problem somewhere. And being intermittent, it will be pretty hard to track down.

There was no code in the TCM? Or any other codes?

 

Is the ECM getting very hot? Is the ECM cooling fan working?