Abstract: Method and system for detecting a high friction within a flow control device of a fuel system are disclosed. For example, the method includes receiving a service test sequence to execute a service test, performing, in response to receiving the service test sequence, the service test to generate test data, the service test including a first test cycle with a first dither level and a second test cycle with a second dither level, wherein the second dither level is different from the first dither level. The method further includes determining whether a performance difference between the first test cycle and the second test cycle exceeds a predetermined threshold based on the test data and detecting, in response to determining that the performance difference exceeds the predetermined threshold, a presence of high friction within the flow control device.