If 3 hyphens (---) are shown on the rear AC control panel, deactivate the child lock in the driver door.Turn the ignition on and off and all should be ok,this fault can occur
If a button is unintentionally pressed on the rear AC control panel for longer than 30 seconds, the fault entry 00003 is sporadically or permanently logged. After the child lock in the driver door has been activated by mistake, it is attempted to switch if off again by pressing the buttons on the AC control panel for some time.