Not sure if your reader picks up the tranmission ECU codes, which can also cause the SES or MIL light to come on.
Also text from the RAVE, in typical dealerspeak:
Malfunction Indicator Lamp (Service Engine Soon)
The MIL illuminates at all times when the ignition is in position II and the engine is not running. If the lamp remains
illuminated or illuminates when the engine is running, a fault has occurred in the engine emission control system or
an emission related automatic gearbox fault has occurred. Stop the vehicle and switch off the ignition for at least 30
seconds. If the lamp illuminates after the engine is restarted, rectification must be sought as soon as possible to avoid
potential engine or gearbox damage and excessive exhaust emissions.