transmission light on

My faithful old lady broke down. Its a 9-5 AERO which I have had for 12 years. Together we have clocked up over 250K miles and all with the same turbo/transmission and engine.. Sure I've replace the DIC 3 times, mas air filters oh and the throttle body twice but this is the first time the transmission light came on. Driving about 60mph and a sudden jolt and then the engine died. Car wouldn't start for about 5 minutes and then fired up with the fault. I was able to drive in limp home mode and then look at the error code.. OBD stated U0100. I was able to clear the code and its driving again... But I'm guessing this will not be the end of the problem... Reading up I'm guessing ECU/CAN wiring issues. Before I start to look/guess where has anybody had this error before and where was the broken cable?
Thanks
Richie.

the main connector on ecu has knowing to cause issue, I will start by that , try to wiggle the cable assembly ..and check for good crimps on it

Thanks for the recommendation. That is where I'll start. I might add some electrical compound to help against fretting.

if you know how to use a multimeter you can check with the help of the WIS (workshop info system) link here

That's again for the suggestion. I'll take a look.