The Sit-N-Lift mobility seat module is capable of storing diagnostic trouble codes. The module emits an audible tone that indicates the diagnostic trouble codes stored by the module. The DTCs are 2 digit codes and the codes are represented by the number of tones for each digit of the code number. For example a DTC 11 is represented with the following sequence: tone, pause, tone, long pause. The diagnostic mode is entered by opening right side door and pressing the door ajar switch 5 times in approximately 4 seconds. The module will immediately begin to flash codes refer to Diagnostic Trouble Code (DTC) List, a code 11 indicates OK. The DTCs will continue to be repeated in this manner until the on-board diagnostics are exited. Diagnostic trouble codes are cleared from the modules memory by removing the main power supply to the module such as the 25 amp circuit breaker or ground for several seconds. To exit the diagnostic mode press the door ajar switch one time.