i have a 1997 s series that randomly shut off when a operating temperature. so this is what i know so far... sometimes when its warm it loses spark and will not start until it has cooled down. i changed the ICM (ignition control module) and both coils and it still shut off on the freeway today. i am stumped anyone had a similar situation?

oh and there are no check engine lights or anything on

 

Change the coolant temp sensor. Go to a GM dealer that still sells Saturn parts and get the sensor and pigtail from them. The aftermarket stuff just doesn't work for Saturns. I don't know why, so don't ask.

 

crankshaft position sensor, when it fails, will cut off spark and fuel
They are known to freak out intermittently like this before permanent failure.
I'd start there