A control system for estimating the tongue length of a trailer being towed by a vehicle in connection with a front wheel steering with or without a coordinated rear wheel steering associated with the vehicle. The control signal system employs an algorithm that calculates an estimated hitch angle between the vehicle and the trailer based on an estimated tongue length, a front wheel steering angle, a rear wheel steering angle, a measured hitch angle, vehicle speed and vehicle yaw rate. The estimated hitch angle is compared to the measured hitch angle to generate a hitch angle error that is converted to a tongue length error. The tongue length error is compared to the estimated tongue length to become a corrected estimated tongue length for a next computation period. After a few seconds of processing, the corrected estimated tongue length will be the actual tongue length of the trailer.