- Fig. 1 Ignition key
You can use the ignition key to switch on the ignition and start the engine.
Starting the engine
Insert the key into the ignition lock.
Manual gearbox: Press the clutch pedal all the way down and move the gear lever into neutral.
Audi A4s with automatic gearbox: Press the brake pedal and move the selector lever to position P or N.
Briefly press the key. The engine should start.
Diesel engines can take a few seconds longer than usual to start on cold days. Please keep your foot on the clutch pedal (manual gearbox) or brake pedal (automatic gearbox) until the engine starts. The indicator lamp 
lights up while the glow plugs are preheating.
lights up while the glow plugs are preheating.Switching the ignition on/off
If you only wish to switch on the ignition and do not want to start the engine as well, proceed as follows:
Insert the key into the ignition lock.
Briefly press the key without pressing the clutch pedal (manual gearbox) or the brake pedal (automatic gearbox).
To switch off the ignition, press the key again.
Diesel engines are automatically preheated when you switch on the ignition.
Electrical components with a high power consumption are switched off temporarily while you start the engine.
You can only remove the key if both the engine and the ignition are switched off Link.
If the engine fails to start immediately, the starter will be switched off automatically after a few seconds. Try to start the engine again.
Start/stop system*
Please note the information on Link.
WARNING!
- Never run the engine in confined spaces. The exhaust gases are toxic – risk of poisoning!
- Never remove the key from the ignition while the Audi A4 is moving. The steering lock could engage suddenly, and you would not be able to steer the car.
- Always take the key with you when you leave the Audi A4. Otherwise the engine can be started or power-operated equipment such as the electric windows can be used. This could result in serious injury.
- Never leave children or disabled people alone in the car. The doors could be locked with the remote control key and the occupants could become trapped in the Audi A4. The Audi A4 occupants could be exposed to extremely high or low temperatures, depending on the time of year.
Caution!
Avoid high engine speeds, full throttle and extreme load conditions until the engine has reached its normal operating temperature; otherwise this can damage the engine.
For the sake of the environment
Do not warm up the engine by running it with the car stationary. You should drive off immediately whenever possible. This will help avoid unnecessary exhaust emissions.
Note
- If the key cannot be removed from the ignition lock, you will have to remove the emergency key to lock the Audi A4 Link.
- When starting from cold the engine may be a little noisy for the first few seconds until oil pressure has built up in the hydraulic tappets. This is quite normal and no cause for concern.
- If you leave your Audi A4 with the ignition switched on, it will be switched off automatically after a while. Please note that electrical equipment such as the exterior lighting will also be switched off.