Sudden shutdowns on Honda Accord EX V6 2000, 80,000 miles

I bought this car 2 years ago and has worked flawlessly. I'm 2nd owner and I know previous owner very well, and am aware car has never had any problems until now.

The problem I'm experiencing is sudden shutdown when going downhill on heavy traffic. Temperature needle appears normal and coolant level is OK. Computer Scan shows all sensors OK, thinking it might be a faulty shutdown sensor.

I replaced the radiator cap for a new one, just to make sure radiator pressure is OK, and mechanic suggested the change of a hose that appeared to be somewhat worn.

It has shut down in this same way 3 times, and once more after replacing cap and hose, but mechanic cannot find what may be wrong, as the car works perfectly at the shop, and showing no signs of overheating. We also suspect of sudden pressure drop from the fuel pump, but nothing sure yet.

Any records of other similar cars having this problem?

I emphasize that sudden shutdown has occured when going downhill in heavy traffic. Being in traffic but in leveled ground has not been a problem.

Thanks for your advice.