Australian Whitegoods Questions? Ask a Technician for Answers ASAP
The E9 code is a high or low pressure code. You do have pressure sensors on the unit. They are in the cooling lines in the outdoor unit, it would look something like this, not actual picture of your unit as I could not find one. You have one on the system for sure. If you put gauges on the system and the pressure checks out good then you need to change out the defective sensor.
First shut off power at the breaker and Clean back of outdoor unit and filters and or blower wheel in indoor unit
Best of luck