(c) civinfo.com - Diagnostika Klimata
Tests
To see what the ECU considers to be the interior temperature, simply turn the temperature up and down until the fan speed is at a minimum.
The diagnostic tests are as follows:
Ignition OFF
Press and hold down the A/C system's Auto and Mode buttons.
Start the engine
Release the buttons
On the A/C - Radio display you'll see the sensor number and the value for that sensor. To advance to the next sensor just press the mirror/rear window defogger button.
1st sensor: Cabin temperature C
2nd sensor: Exterior temperature C
3rd sensor: Solar radiation sensor value (Dark=00, Flashlight=04, Cloudy=10, Sunny=65)
4th sensor: Temperature of the air exiting the air conditioning evaporator C
5th sensor: Drivers air mix opening (low value indicates cooler air distribution, higher value indicates warmer air distribution) % open
6th sensor: Passenger air mix opening (low value indicates cooler air distribution, higher value indicates warmer air distribution) % open
7th sensor: Mode positioning % open
8th sensor: recirc flap % open.
9th sensor: vent output air temperature C
Other test:
Ignition OFF
Press and hold down the Auto and Recirculation buttons
Ignition into II position
Release the buttons
You'll see the "88" at the A/C temperature. If you see any letter from A to P then it means an error message. The messages can be read out only from the HDS system at the service.