Pressing the AUTO switch on the Driver / Passenger temperature control knob so that the are illuminated puts the system on automatic mode. The symbol will have an 'A' within the circle on the display LED.
This is the preferred mode as it allows the system to have fully automatic and simultaneous control of these functions:
- The Air Flow
- The Temperature in the passenger compartment (including dual zones for driver and passenger on systems with the dual zone unit).
- The Air Distribution
- The Air Conditioning
- Automatic Air Recirculation
Although the Air quality sensors can detect most hydrocarbons such as Benzene, Toluene, and gasses such as Nitrogen Dioxide, NO2 (NOx emitted by Diesels), Ozone and Sulphur Dioxide, they can't account for our 4 legged friends or the local farmer muck-spreading. So you'll have to put up with bad smells unfortunately.
So if you were passing through the rural Welsh country side and came across Dai the tractor, you might want to press the Air Re-circulation button once:
This will close off the external air from entering the system. As soon as possible, press it one more time to return to Auto mode. It really is not recommended to have Air-recirculation on for long as you are basically re-breathing exhaled air and carbon dioxide.
The Auto mode will allow the sensors to detect harmful / unpleasant gasses & hydrocarbons and automatically close off the external air for a short period, as well as keeping the air flow distribution and temperature / humidity levels at the optimum levels.