Table of contents: Secret number ↓ Identification number ↓
Audi vehicles are equipped as standard with an anti-theft device. When activated, the device prevents the engine from starting if an attempt is made to start it with a key whose code does not match the one specified.
The anti-theft device consists of:
- anti-theft device control device (built into the instrument panel);
- anti-theft device warning light;
- the control device is matched with the electronic engine control unit;
- reading coil on the ignition switch;
- ignition key with built-in pulse transceiver. This transceiver works without batteries. Each key has its own code.
The anti-theft device is activated when the key is removed from the ignition.
When the ignition is turned on, a signal with the key code is sent through the reading coil to the pulse transceiver built into the ignition key by means of induction.
The key code is read and transmitted to the anti-theft device control unit. There, the code is compared with the recorded value. Then the engine control unit code is checked.
If the received codes match those set on the instrument panel, the anti-theft device indicator light comes on and goes out after approximately three seconds.
If the codes do not match, the warning light will start flashing if the ignition is on but the engine does not start. This may be due to the following reasons:
- a) the reading process is interfered with by other keys on the keychain;
- b) the key code is damaged.
The anti-theft device is checked using the AUDI diagnostic device, which is connected to the diagnostic connector to read the codes of registered faults.
Secret number
The secret number is printed on the keychain of the key ring given to you when you purchase a new car. This number is required to code the new ignition key made due to the loss of the previous one.
Identification number
The identification number is needed so that if the secret number is lost, it can be requested from the plant where the car was manufactured. The identification number is also printed on the keychain. If the identification number is lost, it can be read using a diagnostic device.
(The article is a reprint of material from: «AUDImanual»)