Hello, I have a 2001 Grand Prix gt 3.8 n/s.. Driving to work today and the rpm gauge showed zero (had never happened). And the Trac light came on. The car still drives great so when i got to worked i checked the fluid(fine) and also checked the wheel bearing/hub assembley) both the sensors are still connected and not frayed or pinched any ideas. Like i said it happened on the highway and it still drives fine it just popped on

It sounds like a flaky Crank Position Sensor to me.

Next its going to stall out on you.