The invention relates to a method and system for diagnosing an exhaust recirculation valve based on pressure of a crankcase and provides various methods and systems for diagnosing exhaust recirculation valves (171 and 164) based on the pressure of the crankcase. In one embodiment, the method comprises the step of indicating the conditions of the valves (171 and 164) in a first exhaust channel (162) arranged on the downstream of a cylinder vent valve at least partly based on the pressure of the crankcase.