1
-
Anti-theft system/double locking module
2
-
Travel communication system radio/module (from 99 ½ MY)
6
-
Data link connector (DLC)
7
-
Central timer module (CTM)
9
-
Electronic stability program (ESP) module
11
-
Steering position sensor
12
-
Powertrain control module (PCM)
Module communication is established via two different bus systems; the data link connector (DLC) forms the interface between the modules and the diagnostic tester.
The data bus SCP (Standard Communication Protocol) comprises two twisted wires. Communication takes place along these lines both between the modules themselves and between the modules and the diagnostic tester. Even if there is a break in one of the lines or there is a short to ground or short to power, communication between the modules and the diagnostic tester is still possible on the other line.
The data bus (ISO 9141) comprises a single line. If there is a break in the line or there is a short to ground or short to power, then communication between the module and the diagnostic tester is not possible.
The data link connector (DLC) is a standard 16-pin connector which connects the communication lines (SCP and ISO 9141), the EEPROM programming line and the diagnostic tester power supply.
The steering position sensor passes on the angle of turn of the steering wheel to the electronic stability program (ESP) module and communicates with the electronic stability program (ESP) module and the data link connector via the data bus (SCP).
The electronic stability program (ESP) module controls the anti-lock braking system (ABS), the traction control system (TCS) and the stabilising system. It is connected to the PCM, the steering position sensor and the DLC via the data bus (SCP). A connection to the DLC is also possible via the data bus (ISO 9141).
The ABS module with TCS controls the anti-lock braking system and the traction control system and is connected to the PCM and the DLC via the data bus (SCP). A connection to the DLC is also possible via the data bus (ISO 9141).
The ABS module without TCS has different software to the ABS module with TCS, but is otherwise identical. It is not connected to the data bus (SCP). The ABS module is connected to the DLC via the data bus (ISO 9141).
The vehicle is fitted with either the electronic stability program (ESP) module or the ABS module (with or without TCS).
The powertrain control module (PCM) controls all functions related to engine management and emission control. This module communicates with the electronic stability program (ESP) module, the ABS module with TCS, the instrument cluster and the DLC via the data bus (SCP).
The instrument cluster is connected to the data link connector (DLC) and the PCM via the data bus (SCP), and comprises the following components:
- Speedometer
- Tachometer
- Odometer
- Trip recorder
- Fuel gauge
- Engine temperature gauge
- various warning lamps and indicator lamps
The additional heater is a heating system powered by fuel that heats the coolant in the cooling system of the diesel engine at low ambient temperatures. The additional heater is connected to the DLC via the data bus (ISO 9141).
The airbag module controls the driver and passenger airbags, the side airbags and the pyrotechnic seat belt pretensioner. The module is connected to the DLC via the data bus (ISO 9141).
The central timer module (CTM) is connected to the DLC via the data bus (ISO 9141) and controls time-dependent functions for the following systems:
- Heated rear window and windscreen
- Interior lighting
- Front and rear intermittent wipers
- Front and rear washers
- Seat belt warning
- Ignition key removal lock
- Power saving relay
- Acoustic warning signal
The anti-theft warning system/double locking module is connected to the data bus (ISO 9141) and controls the following functions:
- Luggage compartment release
- Hood release
- Central locking
- Double locking
- Radio remote control
- Anti-theft system
The auxiliary warning system module is connected to the DLC via the data bus (ISO 9141) and has the following functions:
- Washer fluid level low - warning lamp
- Trip computer
- Ambient temperature display
- Ice warning
- Fault code display
from 99 ½ MY: The travel communication system radio/module is connected to the DLC via the data bus (ISO 9141) and has the following components:
- Radio, cassette player, CD player
- Cellular phone
- 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).
