1999 Dodge Caravan Computer goes on vacation / returns

Episode 1: Parked van at work one day, and attempted to start it (cool) at end of work day. Van would start normally, run for 3-5 seconds, and turn off. Giving gas after start made no difference. After 7-8 times, engine refused to even crank. All power equipment continued to function normally, except computer related - no odometer, gauges, tach, trip computer, etc.

24 Hrs later, vehicle started up normally and all computer related equipment was back online, showing correct values.

Since then while driving, all gauges occasionally fall to zero simultaneously, sometimes for a few seconds, sometimes a little longer, but never a stall or failure to start.

Episode 2: (about 3 months later.) Parked van at store. Came out 5 minutes later to start van (warm) and experienced same issue as Episode 1. Start, run 3-5 seconds, shut-down. Gauges and computer related equipment dead. All else functioning. After about 7 or 8 attempted starts, van will no longer attempt to start.

Have not been back to try the 24 hour thing.

Additional piece: Airbag light comes on and goes out intermittently while driving.

Could this be an intermittent PCM connection? Can a PCM take a vacation and return?