On Board Diagnostic Description

Vehicles with power windows have what is referred to as a comfort system (as opposed to a central locking system). Instead of central locking, this system has power windows with door locking units.

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.





The central control module for comfort system -J393- 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 comfort system (comfort system includes 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 VAG 1551 scan tool.

The VAG 1552 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 at 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").



Display Content For Display Group 015

Part 1:

Part 2:

Table
Possible Display
Rear lid/tailgate contact switch 1
Right rear rotary latch switch 2
Left rear rotary latch switch 4
Front passenger rotary latch switch 8
Ignition 16
Interior monitor 32
Hood contact switch 64
Driver's rotary latch switch 128
No alarm 255


Determining the items which have possibly triggered the anti-theft alarm system
The breakdown of the display content illustrated above for display group number 15 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.

Only static DTCs are considered:
- Central locking inoperative
- Mirror positioning motor inoperative
- Power window positioning motor inoperative
- CAN-bus communication inoperative

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.


Interior Monitoring, System Description
The interior monitoring system is a component of the Anti-Theft Alarm (ATA) system. The system consists of two sensors, which are installed ahead of the rear reading lights. The function of the reading lights is integrated within the system. Adjustment for reading light operating conditions occurs on each of the two sensors separately

Interior monitoring sensors operate with an ultrasonic principle. Should movement occur within the vehicle interior while the system is activated, an alarm is triggered via the ATA system.

The interior sensors can be switched off via a button in the B-pillar/door sill and by adaptation (Function 10, channel number 05). After switching off the ignition, remove the key from the ignition lock and press the button to activate and lock the vehicle.

The next time the vehicle is opened the sensors are switched on again.

For all test possibilities consider the system to be operational when the vehicle is locked and a waiting period of 30 seconds is maintained.