Initial Inspection and Diagnostic Overview

Central Locking On Board Diagnostic (OBD)

General Information
The new generation of central locking is capable of On Board Diagnostic. Use of DTC memory, Output Diagnostic Test Mode and Read Measuring Value Block facilitates the search for malfunctions. The central locking system variation can also be coded using the VAG1551 Scan Tool (ST).

Central locking has two pneumatic circuits. For central locking without keyless entry, the first circuit controls only the fuel filler flap; for central locking with the keyless entry system, the first circuit controls both the fuel filler flap and the driver-side door. The second circuit controls all remaining locking points.

On the safety-version of central locking, if the driver-side (or passenger-side door) is unlocked with a single command, then only that door and the first pneumatic circuit are opened. If there is another unlocking command within 5 seconds, the second pneumatic circuit is also triggered and the whole vehicle is unlocked.

If the rear lock cylinder is triggered only once, all doors will remain locked. The rear lid (or tailgate) will automatically re-lock itself after about 5 seconds.

Interior lighting will gradually increase in intensity until fully illuminated (within about 1.5 seconds) when unlocking (fades off when locking).

The control of the luggage compartment lighting proceeds from the central locking pump to the rear lid (or tailgate) contact switch. The lighting will be switched off while the rear lid is open when a certain speed threshold is surpassed (about 5 km/h) or after 10 minutes.

The new remote transmitter now uses radio frequency. For vehicles using the radio frequency remote locking system, the receiver is integrated into the central locking pump. The remote locking antenna is integrated into the wiring harness.

If no doors (or the rear lid) have been opened within 60 seconds after the central locking system is triggered via radio frequency, central locking automatically relocks everything.

If the anti-theft alarm system is armed, central locking cannot be opened via internal buttons.

All vehicles with an anti-theft system are equipped with an ultrasonic interior monitoring system. This could be an interior monitor of the 1st generation (without OBD) or of the 2nd generation (with OBD). All that is necessary is the proper coding of the central locking system. Programming and Relearning

Confirmation can be received from central locking as to whether the alarm system has been armed while locking the doors. The confirmation can be signalled by means of a short anti-theft horn signal or by a brief flashing of the emergency flashers. Central locking can also be coded to give no confirmation at all.

Activation of keyless entry can be signalled by a flashing of the emergency flashers.

On Board Diagnostic (OBD) functions

The following functions are possible:
01 - Check Control Module Versions
02 - Check DTC Memory
03 - Output Diagnostic Test Mode
05 - Erase DTC Memory
06 - End Output
07 - Code Control Module
08 - Read Measuring Value Block