This paper describes the system architecture together with control and diagnostics features of an indigenously developed electric vehicle controller for Light Commercial Vehicle. The key functions of vehicle controller include power management, driveline controls, regeneration and vehicle mode controls. In particular this paper presents vehicle's operational strategy in economy, normal and performance modes based on the vehicle speed and SOC. It also has feature to enable vehicle operation in reduced performance mode at low battery voltages. The battery fault predictor algorithm is also described in detail that is used to control discharge current to prevent sudden dip in SOC and to increase battery life. The vehicle control strategy is modeled & simulated using MATLAB™ environment and results for a specific test case are validated with embedded controllers-in-the-loop in a test-bench environment. The electric vehicle controller is implemented with a fully integrated Battery Management System, motor controller and other auxiliary subsystems. The test-track results of electric vehicle driven in different operating modes are analyzed for the performance metrics. The results of three stages of development namely the simulation, test-bench validation and vehicle performance are presented.