Why Is My Car Suddenly Immobilized?

When I crank the car, it turns over, but then stalls. The dash light "Immobilizer" light is flashing after the car stalls. Also the temperature needle as well as the fuel needle spins all the way up, all the way down and then all the way back up. In the trip odometer display, it says DEF. the period is flashing after it. At the same time, the total mileage odometer has all zeros. I turned on the radio and it will bring up the word "SAFE" and then "1000". With the radio preset buttons, I can manipulate the numbers to any four numerical order. After examining the car, I noticed pooling water in the drivers and drivers side backseat floorboard. I vacuumed all that up and air dried the car throughout the week and still no luck on starting the car.   I did have my front passenger axle replaced about 10 days before these symptoms. Could that relate? I would really appreciate any ideas that might be causing these problems.