Whenever a problem is observed, it is required to classify the problem by its origin being electrical, mechanical or hydraulic before contemplating on the repair process. Diagnosis dependent on knowledge of operation and construction of the transmission, as well as use of special tools, means that diagnosis of problems with the automatic transmission should be given to the dealer service department or other authorised repairer. Also, a defective transmission should not be pulled out before a competent mechanic with the right equipment examines the car because testing that involves the transmission has to be done with the transmission still in the car.