Operation CHARM: Car repair manuals for everyone.

On Board Diagnostic Description




The new generation of central locking operates using the electric motor principal. The lock units located in the doors (door locks) have an electric motor.

After receiving a lock command (either from a door lock or remote), the vehicle is locked and the alarm is armed. The sunroof and any open windows will be closed. Lock status is reported to the control module via the locking unit contact switches

All the known comfort functions can be performed with the electric comfort system, including interior light control, Anti-Theft Alarm (ATA) with interior monitoring (being prepared), power windows, mirror and the radio frequency remote control.

Should the airbag control module activate an airbag, a signal is automatically sent to the central locking control module to unlock the doors and switch on the interior lighting.







The central control module for the central locking system -J379- is located under the instrument panel and is secured by a bracket to the steering column. It is equipped with DTC memory. The Data Link Connector (DLC) is located under trim beneath the steering wheel.

The control module recognizes malfunctions in the central locking comfort system (comfort system includes central locking, anti-theft alarm, power windows, radio frequency remote control, mirror) and stores them in permanent memory.

To begin troubleshooting, initiate On Board Diagnostic (OBD) and retrieve the stored information with the VAG1551 scan tool.

The VAG1552 mobile scan tool may also be used.

The malfunction information displayed is used to refer to a Diagnostic Trouble Code (DTC) table with notes on the possible causes of malfunctions and specific corrective actions.

Malfunctions which can be attributed to a temporary open circuit in the wiring or a loose connection will also be stored. These malfunctions will be displayed as sporadic DTCs ("/SP").

NOTE: Before changing a component erase DTC memory, perform functional checks, and check DTC memory again.


Function Display
The optical function display of the central locking system occurs with an LED in the driver's door panel.

The LED flashes for 28 days after locking occurs and goes out only when the lock is not activated within this time.

The function of the anti-theft alarm (ATA) system is not always displayed.

Determining The Items Which Have Possibly Triggered The Anti-Theft Alarm System
The breakdown of the display content illustrated on page 01-222 for display group number 10 gives information as to which component triggered the alarm system last, and can therefore aid in the troubleshooting and repair process.

This "DTC memory" cannot be erased.