Did you know your Audi TT 8N Climatronic can do much more than just control the temperature?
There’s a hidden service menu that lets you read live vehicle data, such as road speed, engine temperature and outside temperature. Very handy if you want to quickly check something without a laptop or OBD tool.
On this page you’ll find step-by-step instructions to activate the hidden menu and an overview of the most interesting values for TT 8N drivers.
How to open the hidden Climatronic menu?
Opening the hidden menu always follows the same sequence:
- Switch on the ignition (you don’t have to start the engine, but you can).
- Press the following buttons at the same time:
• Air recirculation
• Air distribution to top (airflow to the windscreen / upper vents) - The Climatronic now switches to the diagnostic menu.
- Use the temperature control (+/–) to scroll through the different parameters.
- Have you found the parameter you want?
• Press the air recirculation button again to confirm and display it. - Repeat steps 4 and 5 to read another value
- Finished reading values?
• Press the AUTO button to return to normal mode.
Or watch the video on the right with the how-to and the PDF with an overview of the values to be read.
Useful values to read
There are dozens of channels available (see PDF), but in daily use a few are especially useful. Below you’ll find a selection of the most interesting parameters for the Audi TT 8N:
Channel | Description | Unit | Practical use |
17 C | Vehicle speed | km/h | Compare cluster speed with GPS |
20 C | System voltage | Volt | Test of the alternator; value between 13.5 - 14 Volt when engine runs |
27 C | Engine speed (rpm) | rpm | Accurate engine speed reading |
49 C | Coolant temperature | °C | Check cooling system operation |
51 C | Engine temperature | °C | Monitor engine operating temperature |
55 C | Outside temperature | °C | Reference vs. outside temp shown in the car |
Test werking dynamo; waarde tussen 13,5 - 14 Volt bij draaiende motor
Why is this useful?
A few situations where the Climatronic menu really comes in handy:
- Check your speedometer
Compare channel 17 (vehicle speed) with a GPS app. This shows you how much your speedometer is over-reading. - Track down cooling issues
With channels 49 and 51 you can see whether the engine reaches proper operating temperature and whether cooling fans switch on in time. - Read engine speed precisely
Channel 27 gives you the exact rpm. Useful when checking idle speed or just out of curiosity. - Get to know your TT 8N better
By occasionally checking the engine temperature, you will get to know your TT 8N better and see when the engine is at the right temperature.
Even if your instrument panel suffers from the typical TT 8N problem of the gauges showing incorrect values, such as an incorrect engine temperature, you can use the Climatronic to check whether the gauges are acting up or whether there may be something wrong with the cooling system.
Tips & warnings
- Don’t fiddle while driving
Scrolling through the menu can be distracting. Choose your parameters while stationary whenever possible. - Don’t change unknown settings
The Climatronic menu is meant for reading values, not for experimenting with adjustments. Avoid unknown channels.
Use it as an extra tool - See the Climatronic as an extra source of information. For real faults or error codes, a proper diagnosis with VCDS or a specialist remains the best option.
Please note |
© Header photo: Arno Lingerak (Autovisie)

