Could anyone advise what these codes mean?

 

1.6 petrol 2007 Roomster

first 2 relate to the HVAC ECU, specifically the motor which operates the recirc flap is intemittent in operation. 1596, if it works OK the code should clear.

 

65535 can appear anytime, even scanning the car can cause it, that should clear no issue, its an issue when related to "important" stuff like airbags and ABS etc.

 

1598 - drive battery voltage is saying the battery is low or no good. Worth checking ALL connections at the battery and the main terminals are clean and tight.