Initial Inspection and Diagnostic Overview

Central Locking System, On Board Diagnostic (OBD)

General information
Operation of the new central locking generation is based on electric motors rather than the previous pneumatic principle.

The lock units in the doors (door locks) each have 2 electric motors, whereas the trunk lid/tailgate and filler neck compartment lid only have one each.

The first motor locks the doors, the second is responsible for the deadlock function, i.e. following a lock command from an exterior control point (door lock, remote control) the vehicle is safeguarded against theft and can no longer be unlocked from inside. Feedback to the control module on the respective status is provided by way of contact switches in the lock units.

The electric central locking permits implementation of all the familiar convenience functions, interior lighting control, security central locking, anti-theft alarm with interior monitor and remote control.

For matching of new remote control keys or renewed matching of remote control keys which have exceeded the adaptation limit.

Triggering of the airbag control module automatically causes a signal to be transmitted to the central locking control module to unlock the doors and switch on the interior lighting.

The control module detects faults and malfunctions in the electric central locking and stores them in a non-volatile memory.

On commencing troubleshooting procedure, start On Board Diagnostic (OBD) and check the information stored using VAG 1551 Scan Tool (ST).

It is also possible to use the system tester V.A.G 1552.

All the functions implemented to date using V.A.G 1551/1552 can also be performed with the new tester VAS 5051 in vehicle On Board Diagnostic (OBD) mode.

On Board Diagnostic (OBD) functions

Possible functions:
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
10 - Adaptation