When your RC car stops running although steering still works, you can troubleshoot by following these steps. First you want to check the battery level. Some ESCs may cut off power if voltage drops below a certain level. If your battery still has power in it, try to spin each wheel individually to determine if anything is stuck. If they can all spin freely, remove the motor pinion and see if the car can move on the ground when you push it. If the car can be moved by hand smoothly, the drive train is healthy so chance is that it is a motor issue. If not, then it is a drive train problem – something is wrong inside one of the gearboxes.