System Overview

System overview

Control module




The most important task of the upper electronic module is to manage the following functions:
- Siren
- Sun roof
- Movement sensor
- Rain sensor
- Interior roof lighting
- Cargo compartment lighting (V70 and V70XC)
- Sun visor lighting
- Remote control
- Automatic rear view mirror anti-dazzle
- Seat belt reminder.
The control module is integrated in the rear view mirror. If the control module is replaced, the rear view mirror assembly must also be replaced.
The upper electronic module communicates partly with components which are directly connected and partly with other control modules and components via serial communication and the Control area network (CAN).
The control module checks activations and input and output signals through an integrated diagnostic system A diagnostic trouble code (DTC) is stored if the control module detects an error. In certain cases the upper electronic module replaces the faulty signal with a substitute signal.
Diagnostic trouble codes (DTC) are stored in the control module memory. The data can be read off using the VIDA.
A simple way to check that the upper electronic module is supplied with power is to activate the seat belt reminder function Activate the seat belt reminder by sitting in the driver's seat. Switch on the ignition, do not fasten the seat belt. If the seat belt reminder lights, the upper electronic module is supplied with voltage. Another way of checking that the upper electronic module is supplied with voltage is to switch on the rear reading lamps.
For information, also see Signal specifications.

Signals
The table below summarizes input and output signals to and from the upper electronic module. The signal types are divided into directly connected signals, serial communication and Control area network (CAN) communication. The illustration below displays the same information and the Volvo part numbers.