A system and method for test loop timer operation. A mobile station implementing a test procedure may receive a command to enter a test mode. A timer may be enabled and RLC data blocks may be transmitted. The timer may be disabled when a quantity of the RLC data blocks exceeds a transmit window size or when a countdown value is equal to zero. The the test mode may be a switched radio block loopback mode and the timer may be a T3182 timer. Embodiments of the invention may be implemented in a mobile communication system.