Communication network (vehicles up to 08.2001)

Pos.	Spare Part No	Name
1		Anti-theft/double door lock module
2		Radio/traffic communication module (from model year 99)
3		Trip computer module
4		Dashboard
5		Airbag module
6		Data link connector (DLC)
7		Central timer module (CTM)
8		ABS module
9		Sustainability e-program module (ESP)
10		Additional heater
11		Steering wheel position sensor
12		Powertrain control module (PCM)

Communication between modules is established using two different bus systems; data circuit connector (DLC) forms an interface between the modules and the tester of the diagnostic system.

SCP data bus (Standard corporate protocol) has two paired wires. Communication over these lines is established both between the modules themselves and between the modules and the tester of the diagnostic system. Even in the event of a break in one of the lines, a short circuit to "mass" or a short circuit to the power supply, communication between the modules and the diagnostic tester is maintained by another line.

Data bus (ISO 9141) has one line. In the event of a break, short circuit to "mass" or a short circuit to the power supply, communication between the module and the diagnostic system tester is not possible.


Data link connector (DLC) - This is a standard 16-pin connector that connects communication lines (SCP and ISO 9141), programmable EEP-ROM line and diagnostic system tester power supply.

The steering wheel position sensor sends the steering angle value to the electronic stability program module (ESP) and communicates with the Electronic Stability Program module (ESP) and data link connector via data bus (SCP).

Electronic Sustainability Program Module (ESP) controls the anti-lock braking system (ABS), traction control system (TCS) and stabilization system. This module is connected to the PCM module, steering wheel position sensor and DLC channel via the data bus (SCP). Connection to DLC is also possible via data bus (ISO 9141).

The ABS module with TCS controls the anti-lock brake system and traction control system and is connected to the PCM and DLC via the data bus (SCP). Connection to DLC is also possible via data bus (ISO 9141).

The software of the ABS module without TCS is different from the software of the ABS module with TCS, but they are otherwise identical. This module is not connected to the data bus (SCP). ABS module connected to DLC via data bus (ISO 9141).

The vehicle is equipped with either an electronic stability program module (ESP), or ABS module (with or without TCS).

Powertrain control module (PCM) controls all functions related to engine management and exhaust system. This module communicates with the Electronic Stability Program module (ESP), ABS module with TCS, instrument panel and DLC via data bus (SCP).


The instrument panel is connected to the data circuit connector (DLC) and PCM via data bus (SCP), and includes the following elements:

• Speedometer
• Tachometer
• Odometer
• Odometer
• Fuel gauge
• Engine temperature gauge
• Various indicator and warning lamps

The auxiliary heater is a heating system device powered by the fuel system that heats the coolant of the diesel engine cooling system at low outside temperatures. Additional heater connected to DLC via data bus (ISO 9141).

The airbag module controls the driver and passenger airbags, side airbags and pyrotechnic seat belt pretensioners. This module is connected to the DLC via a data bus (ISO 9141).

Central timer module (CTM) connected to DLC via data bus (ISO 9141) and controls the time-dependent functions of the following systems:

• Heated rear window and windshield
• Interior lighting
• Intermittent wipe mode front and rear wipers
• Front and rear windshield washers
• Seat belt warnings
• Ignition key removal lock
• Energy saving relay
• Audible warning signal

Anti-theft alarm/double door lock module connected to data bus (ISO 9141) and controls the following functions:

• Opening the luggage compartment
• Hood opening
• Central locking
• Double blocking
• Radio remote control
• Anti-theft system

Additional alarm system module connected to DLC via data bus (ISO 9141) and has the following features:

• Low windshield washer fluid level - warning light
• Trip computer
• Outdoor temperature display
• Ice Warning
• Fault code display

From model year 99: Radio/traffic information system connected to DLC via data bus (ISO 9141) and include the following elements:

• Radio, cassette player, CD player
• Cellular telephone
• Navigation and emergency call system

Communication between modules

The engine speed signal for the tachometer, the engine temperature signal for the coolant temperature display, and the signal for the speedometer are sent by the PCM to the instrument cluster via the data bus (SCP).