A fault-tolerant control design strategy based upon sliding mode control and a descriptor observer for Upschitz system is presented. The aim is to mitigate the vehicle speed faults and provide accurate measurements for the control. Thus, the additive faults affecting the vehicle speed sensor are estimated, and accurate speed measurments are used to control the vehicle speed instead of the faulty ones. Sufficient conditions and obsrever gain are designed by use of Lyapunov theory, satisfying L 2 -gain norm and H ∞ enterions. These conditions are derived under the well known Linear Matrix Inequality. The optimal designed gains ensure robustness against disturbances and additive sensor faults. A nonlinear longitudinal vehicle dynamic is considered to demonstrate the performance of the proposed design to achieve the spacing control task. Computer simulations are addressed to validate the proposed controller in autonomous vehicle scenario.