Transmission Slip Out Of Gear problems of the 2010 Dodge Avenger

The vehicle on three separate turn arounds did the same thing after 3 plus hrs of driving stopping shifting into reverse then drive. Near the end of the rural/local 4 straight hrs transmission appeared to not shift out of first gear. Each time the vehicle came to a complete stop while applying brakes. The car was then shifted into r(reverse) and the brake pedal was released and gas pedal applied approximately. After reaching the reversed turning destination the brake was reapplied and car came to a stop. Car was shifted into d (drive) from r (reverse) and all three times the car accelerated to 30 -34 mph rpms staying at 3 and the automatic transmission did not did not go into normal 2nd year mode. All three times the car was completely stopped. The gearshift put into p(park for 5sec. ) then gear shift put into d. The car ran fin again until time to turn around. On the 3rd attempt the check engine light came on and immediately the car was driven home under 40 mph 4rpms. After the vehicle has set for 2 plus hrs the fluids were checked and none appears low the car also drove as normal as it had at the beginning of the last trip. The car was only driven for 5-10minutesvand all gears seam to work fine fluids are normal and the check engine symbol is still lit.