Electrical Components - Design and Function: Overview Volvo XC90 I

READING OFF THE CONTROL MODULE IDENTIFICATION

The diagnostic tool identifies control modules by reading off a number of codes from the control module memory.

The codes contain information about the control module

1. hardware P/N (control module without software)
2. hardware serial number (control module without software)
3. software P/N
4. diagnostic software P/N

OVERVIEW

The vehicle's electrical system consist of a number of control modules on the CAN and MOST network. The functions of the vehicle can be divided between the different control modules in the vehicle. The vehicle's different functions are implemented via the CAN and MOST network. Each control module is loaded with software that executes functions and monitors the control module through integrated diagnostics.

Incorrect or failed functions in the vehicle usually depend on hardware faults, for example, contact play, oxidation, breakages or short-circuiting.

Software is not worn out and its function is not impaired overtime, however, unforeseeable behaviour can occur in software which means it needs to be upgraded. It may also be necessary to upgrade software on account of legislation or when moving to another market.

When starting the control module the primary bootloader starts (PBL) for 20 ms (0.02 seconds). Should the control module receive a programming command (prog) during these 20 ms the control module enters programming mode.

The programming command is sent for approximately 2 seconds so that all control modules have time to execute the command and enter programming mode. If no programming command is sent the control module's application software takes over the function of the control module.

If a reset command is sent to the control modules in programming mode, the control modules will enter normal operating mode.

The primary bootloader means it is always possible for a control module to enter programming mode even if the application software has been corrupted, for example, during unsuccessful downloading.

The control module has a built-in diagnostic system, Volvo Diagnostic, which continuously monitors internal functions as well as input and output signals.

The control module has a built-in diagnostic system, Volvo Diagnostic, which continuously monitors internal functions as well as input and output signals.

READING THE CONTROL MODULE IDENTIFICATION

VIDA identifies control modules by reading off a number of codes from the control module memory.

The codes contain the following information about the control module

1. hardware P/N (control module without software)
2. hardware serial number (control module without software)
3. software P/N
4. diagnostic software P/N.

DESCRIPTION OF PARAMETERS

Note. The parameters that can be read off for the steering wheel module display how the steering wheel module interprets the position on the buttons and control stalks. In the event of a fault in the buttons or the wiring, the status will be constantly On or Off depending on the position on the buttons and control stalks.

The control module has a built-in diagnostic system, Volvo Diagnostic, which continuously monitors internal functions as well as input and output signals.

VIDA identifies control modules by reading off a number of codes from the control module memory.

The codes contain information about the control module

1. hardware P/N (control module without software)
2. hardware serial number (control module without software)
3. software P/N
4. diagnostic software P/N.

READING OFF CONTROL MODULE IDENTIFICATION

VIDA identifies control modules by reading off a number of codes from the control module memory. The codes contain information about the control module

1. hardware P/N (control module without software)
2. hardware serial number (control module without software)
3. software P/N
4. software number, diagnostics
5. serial number, side impact sensor.

The following information can also be read off from the control module memory

1. hardware part number for occupant weight sensor (OWS) (certain markets and models only)
2. software part number for occupant weight sensor (OWS) (certain markets and models only)

VIDA identifies the control modules by reading off a number of codes from the control module memory.

The codes contain information about the control module's

1. hardware P/N (control modules without software)
2. hardware serial number (control modules without software)
3. side impact sensor serial number
4. software P/N
5. P/N diagnostic software.

CAN (Controller Area Network) is a standardised system for multiplex-communication. Volvo has developed a new standard for multiplex communication - VOLCANO. VOLCANO is a further development of CAN and operates with real time operation and prioritising. The description of prioritising is developed from VOLCANO but is designated CAN.

The standard for Control area network (CAN) specifies

1. That two cables should be used (CAN H and CAN L)
2. Which voltage levels should be used
3. What a message should look like
4. How transfer errors should be handled.

Scheme 1

The CAN H and CAN L cables must not be confused with HS CAN and LS CAN which are speeds on the Controller area network. CAN H and CAN L are a way of distributing signals within the multiplex communication network.

Communication occurs through two cables. These two cables are paired together. CAN H is always white and CAN L is always green.

The cables are made of copper and are easily identified by the green and white colouring.

The voltage levels for communication occur using differential voltage levels.

The reason for communicating using paired cables and differential voltage levels is that the network becomes less sensitive to interference.

The same message is transferred simultaneously by both cables, but different voltage levels are used.

1. Binary 1 = 2.5 V on both CAN H and CAN L.
2. Binary 0 = 4 V on CAN H and 1 V on CAN L.

Average voltage level is 2.5V.

Scheme 2

The message consists of the following components

1. Identifier ("flag"), which indicates the message identity and prioritisation
2. Data information (value, information etc.)
3. Check sum, used to check that the message has arrived correctly
4. Stop signal, which indicates that the message has finished.

A complete Controller area message is called a frame.

The Controller area network (CAN) is monitored and controlled by the central electronic module. When the central electronic module detects a fault in the controller area network a diagnostic trouble code (DTC) is set in the central electronic module. There are different diagnostic trouble codes depending on the type of malfunction detected.

Types of error which are handled are

1. Electrical faults
2. No communication from the control module
3. Faulty communication.

Increasing demands for further functionality in the car, both by statutory requirement and customers, have led to an increased complexity in the car.

This has in turn driven the development of more flexible electronic systems. The Controller area network (CAN) is a result of this research. The network allows a large number of different commands and messages to be transmitted and received on the same cable. Previously each command or message required a separate cable. By using the network functionality has increased without increasing the number of cables.

The number of commands and messages that can be handled by the network depends on the speed of the network and the length of the message / command. The Volvo network which is based on a Controller Area Network (CAN), can transmit over 500 different signals and approximately 100 messages (also known as frames). Each message can contain several signals, for example a message to the rear electronic module can contain all the signals for how the tail lamps should be lit.

The network is made up of a number of control modules (sometimes called nodes)which are connected to each other serially via two communication cables. Each control module is supplied with power and grounded individually and receives messages /commands via the two communication cables. In both networks (high and low speed sides) the control modules are serially connected. In the event of an open-circuit those control modules beyond the open-circuit will not be able to communicate with other parts of the network.

CAN (Controller Area Network) is a standardised system for multiplex communication. Multiplex communication means that you can transmit messages between one or more control modules on the same wires without communication between the various control modules disrupting one another. Volvo has produced a new standard for multiplex communication, known as VOLCANO. VOLCANO is a further development of CAN and works with real-time processing, as well as prioritisation. The description of prioritisation is based on VOLCANO but named CAN.

The standard for Control area network (CAN) specifies

1. That two cables should be used (CAN H and CAN L)
2. Which voltage levels should be used
3. What a message should look like
4. How transfer errors should be handled.

The network is made up of a number of control modules (sometimes called nodes)which are connected to each other serially via two communication cables. Each control module is supplied with power and grounded individually and receives messages /commands via the two communication cables. In both networks (high and low speed sides) the control modules are serially connected. In the event of an open-circuit those control modules beyond the open-circuit will not be able to communicate with other parts of the network.

Scheme 3

The network consists of two parts: a high speed side (HS CAN) which transmits signals/messages between the central electronic module (CEM) and control modules mainly in the engine compartment, and a low speed side (LS CAN) which transmits signals/messages between the central electronic module (CEM) and control modules in the passenger compartment and the luggage compartment.

The interface between the high and low speed sides is supplied by the central electronic module (CEM) which converts the transmission speed up or down for communication between the two network sides.

Scheme 4

The data link connector is located in the passenger compartment near the driver's station, cables for high-speed side (HS CAN) and low-speed side (LS CAN) are connected to the data link connector.

Scheme 5

1. Pin 3 LS CAN (low-speed side) (H-cable)
2. Pin 4 Chassis ground
3. Pin 5 Signal ground
4. Pin 6 HS CAN (high-speed side) (H-cable)
5. Pin 11 LS CAN (low-speed side) (L-cable)
6. Pin 14 HS CAN (high-speed side) (L-cable)
7. Pin 16 Voltage feed

Note. The data link connector's other connections may be used by other functions. This section only decribes connections related to CAN.

The CAN network is monitored by the central electronic module (CEM). When the central electronic module (CEM) detects a fault in the CAN network, a diagnostic trouble code (DTC) is stored in the central electronic module (CEM). There are various types of diagnostic trouble code (DTC), depending on the type of fault.

Types of error which are handled are

1. Electrical faults
2. No communication from the control module
3. Faulty communication.

Note. To troubleshoot respective CAN-net, see troubleshooting for CAN-related diagnostic trouble codes for Central electronic module (CEM). For example, choose any of CEM-DF01 - DF17 depending on CAN-net.

Increasing demands for further functionality in the vehicle, both statutory requirements and customers, have led to increased complexity in the vehicle.

This, in turn, has encouraged developments towards more flexible electrical systems. The CAN-net (Controller Area Network) is a result of this research. The network permits the transmission and receipt of a large number of different commands and messages on the same wiring. Earlier, every command or message required a separate cable. Using networks has allowed functionality to be expanded without increasing the number of cables.

The number of commands and messages which can be handled on the network depends on factors such as the network speed and the length of the message or command. The Volvo network which is based on a control area network (CAN), can transmit over 500 different signals and approximately 100 messages. These messages are also called frames. Each message can contain several signals, e. g., a message to Rear electronic module (REM) can contain all signals for how the tail lights should be lit.

see OVERVIEW

Scheme 6

The transmission control module (TCM) is positioned in an air cooled plastic box in the engine compartment together with the engine control module (ECM).

Scheme 7

The shift solenoids S1 and S2 are positioned in the valve housing, which is mounted behind the side cover of the transmission. The shift solenoids (on/off type), consist of an electrical coil which controls a hydraulic valve. The solenoids are supplied with 12 V via the transmission control module (TCM) and grounded at the ground terminal. The shift solenoids control shifting and the transmission control module (TCM) determines which gear is to be used by activating them in different patterns.

There is a diagnostic for the electrical function of the shift solenoids. There is also a diagnostic for the hydraulic circuit, but not for the hydraulic function of the solenoids.

Scheme 8

Lock-up solenoid SL is positioned in the valve housing, which is mounted behind the side cover on the transmission. The lock-up solenoid consists of an electrical coil which controls a hydraulic valve. The solenoid is controlled by pulse width modulation (PWM) voltage and is grounded at the ground terminal. The solenoid controls lock-up engagement of the torque converter. Engagement occurs through solenoid pulsing which provides a smooth lock-up engagement function. Power transmission then changes to mechanical power transmission through the torque converter. The hydraulic function of the solenoid is linear.

There is a diagnostic for the electrical function of the solenoid, but not for the hydraulic function.

Scheme 9

The lock-up pressure sensor is positioned in the valve housing, which is mounted behind the side cover for the transmission. The lock-up pressure sensor consists of six electrical pressure switches. The pressure switches indicate the hydraulic pressure in the different transmission systems. The pressure sensor provides the transmission control module (TCM) with information about the system pressure and selected gear. The transmission control module (TCM) uses this information to control the lock-up solenoid, SL.

There are diagnostics for the lock-up pressure sensor.

Scheme 10

The line pressure solenoid, STH, is positioned in the valve housing, which is behind the side cover for the transmission. The line pressure solenoid consists of an electrical coil which controls a hydraulic valve. The solenoid is controlled by pulse width modulation (PWM) voltage and is grounded via the transmission control module (TCM). The function of the solenoid is linear. The hydraulic valve is controlled by the varied current which is the result of the pulse conditions. During high pulse conditions, (at high current (approximately 1A)) the line pressure is low. During low pulse conditions (at low currents) the line pressure is high. In the event of an open-circuit, the line pressure reaches maximum which will result in harsh gear shifting. This can also result in a whining noise from the transmission pump. The hydraulic valve is then completely open.

There are diagnostics for the solenoid. There is a diagnostic for the electrical function of the solenoid. There is also a diagnostic for the hydraulic circuit, but not for the hydraulic function of the solenoid. The hydraulic tests can be carried out using a mechanical pressure gauge. The idle and stop pressure can be checked.

Scheme 11

The transmission input speed sensor, (input shaft speed) is positioned in the transmission housing. The sensor is an active sensor and is supplied with 12 V. When the driven gearwheel rotates, the sensor generates a pulsed current (quadratic wave) where the strength of the current depends on the position of the pulse wheel. The signals from the coil in the sensor are then effected by a magnetic resistance element, which generates a current which oscillates between 7 mA and 14 mA, and the frequency of which increase with speed. The transmission control module (TCM) calculates the transmission input speed using the signal from the sensor.

The input speed is compared with the transmission output speed from the transmission speed sensor signal to calculate the gear ratio.

There are diagnostics for the transmission input speed sensor.

Scheme 12

The transmission output shaft speed sensor is positioned on the transmission housing. The sensor is electro-magnetic and acts on a toothed pulse wheel. The sensor provides signals to the transmission control module (TCM) about the vehicle speed. The transmission speed sensor is an active sensor and is supplied with 12 V. When the pulse wheel rotates, the sensor generates a pulsed current (quadratic wave) where the strength of the current depends on the position of the pulse wheel. The signals from the coil in the sensor are then effected by a magnetic resistance element, which generates a current which oscillates between 7 mA and 14 mA, and the frequency of which increase with speed. The control module calculates the transmission output speed using the signals from the sensor. The signal is compared with the signal from the transmission input speed sensor and is used to calculate the gear ratio as well as for diagnostics.

There are diagnostics for the transmission output speed sensor.

Scheme 13

The temperature sensor is the NTC resistive type. The temperature sensor is positioned on the valve housing inside the side cover and measures the transmission fluid temperature in the oil pan. The temperature sensor is supplied with 5 V and is grounded via the transmission control module (TCM). The control module can determine the transmission fluid temperature by measuring the voltage drop across the NTC resistor of the sensor. The control module stores the time the temperature has been within a certain temperature range. If a certain temperature and time has been exceeded, a diagnostic trouble code (DTC) indicating that a oil change is necessary is stored.

There are diagnostics for the temperature sensor.

Scheme 14

The gear-shift position sensor is located inside the transmission housing. It contains a Park / Neutral position (PNP) switch and switches which inform the transmission control module (TCM) about which gear is selected and whether back-up (reverse) gear is selected so that the reversing lamps are lit. The gear-shift position sensor is a position switch which is grounded via the chassis. The combination of pins A, B, C and PA indicate the current gear selector position (see the table below). The trailing contacts can either be closed or open. The gear-shift position sensor is not available as a replacement part.

There are diagnostics for the gear-shift position sensor.

Scheme 15

Table for the gear-shift position sensor

The value indicates the position of the gear-shift position sensor (A, B, C and PA), see the table.

= High signal (open)

= Low signal (grounded)

Scheme 16

The gear selector assembly is positioned in the center console and is mechanically connected to the transmission by a cable which moves the gear valve in the valve housing. The gear selector module (GSM) is positioned on the top panel of the gear selector assembly.

The gear selector module (GSM) receives gear position signals from the transmission control module (TCM) via serial communication. The transmission control module (TCM) receives the present gear position from the gear-shift position sensor. The LEDs in the top panel indicate the selected gear to the driver. The gear selector module (GSM) communicates serially with the central electronic module (CEM). The central electronic module (CEM) sends a signal to the gear selector module (GSM) to activate the shift-lock. The power supply and ground for the shift-lock solenoid are directly connected to the gear selector module (GSM).

The "W" switch in the gear selector assembly top panel is positioned on the printed circuit board for the gear selector module (GSM) and activates Winter mode. The gear selector module (GSM) checks the back-up (reverse) inhibitor function based on the vehicle speed signal from the transmission control module (TCM).

There are diagnostics for the gear selector module (GSM). Diagnostic trouble codes (DTCs) are stored in the transmission control module (TCM) in the event of a fault.

The control unit has built-in diagnostics, Volvo Diagnostics, which continually monitor the system and the input and output signals.

READING THE CONTROL UNIT IDENTIFICATION

VIDA identifies control units by reading the number of codes from the control unit memory.

The codes contain information on the control unit as follows

1. hardware component number (control unit without software)
2. hardware series number (control unit without software)
3. software component number
4. diagnostic software component number

VIDA identifies the control modules by reading off a number of codes from the control module memory.

The codes contain the following information about the control module

1. the hardware P/N (control modules without software)
2. the hardware serial number (control modules without software)
3. the software P/N
4. the diagnostic software P/N

Scheme 17

The Transmission Control Module (TCM) is integrated with the gear position indicator as one unit. The unit is fitted in the top side of the transmission housing, on the gear selector shaft. The control module's connector is directly connected to the transmission.

The control module can be identified by means of reading off a number of codes.

1. hardware P/N
2. hardware serial number
3. software P/N
4. diagnostic software P/N

SYSTEM OVERVIEW

GENERAL

Scheme 18

TF-80SC (TF-80SC AWD) is 6-speed electronically controlled automatic transmission with lock-up function on the five highest gears. The Transmission Control Module (TCM) adapts gearshifts so that the correct gear is always selected with respect to driving style, engine load, driver requirements, speed etc. This provides good fuel economy and increased comfort through gentler gearshifts and lower noise level.

The Transmission Control Module (TCM) receives information on required gear position and required driving style (driving program) from the driver. Together with signals from a number of sensors in the transmission and the engine management system, this enables the calculation of optimum gearshift timing and lock-up engagement, in contrast to a gearbox with only a hydraulic control system. The control module takes consideration of small changes in operating conditions and adapts the different transmission functions so that the correct gear is always selected in accordance with the driving program selected by the driver.

The Transmission Control Module (TCM) has an adaptive capacity intended to ensure even gearshift quality during the whole service life of the transmission.

In order to be able to determine gearshift timing and lock-up engagement precisely, based on the selected driving program, the control module receives information on the following

1. Selected gear position - from the gear position indicator.
2. Speed of transmission input shaft - from transmission speed sensor, input shaft.
3. Speed of transmission output shaft - from transmission speed sensor, output shaft.
4. Transmission oil temperature - from temperature sensor in the transmission.
5. Engine speed and torque, and throttle opening - from Engine Control Module (ECM) via the Controller Area Network (CAN).
6. Whether and how much the accelerator pedal is depressed - from Engine Control Module (ECM) via the Controller Area Network (CAN).
7. Engine temperature - from Engine Control Module (ECM) via the Controller Area Network (CAN).
8. Vehicle speed - from Brake Control Module (BCM) via the Controller Area Network.
9. Whether and how much the brake pedal is depressed - from Brake Control Module via the Controller Area Network.

Scheme 19

The following components are included in the automatic transmission control system

1. Transmission Control Module - Controls activation/deactivation of the solenoids by means of processing the input signals from the transmission speed and temperature sensors. Also stores adaptive data and diagnostic trouble codes and frozen values for diagnostics.
2. Gear position indicator, integrated with Transmission Control Module - Provides Transmission Control Module information on selected gear position.
3. Solenoid - Controls engine braking on 1st gear.
4. Solenoid - Controls engine braking on 1st gear.
5. Lock-up solenoid - Controls the lock-up function and also used with certain shiftings.
6. Linear pressure solenoid - Controls transmission system pressure.
7. Linear pressure solenoid - Controls transmission shift pressure and also used with certain shiftings.
8. Linear pressure solenoid - Controls transmission shift pressure and also used with certain shiftings.
9. Linear pressure solenoid - Controls transmission shift pressure and also used with certain shiftings.
10. Linear pressure solenoid - Controls transmission shift pressure and also used with certain shiftings.
11. Speed sensor, input shaft (1) - Provides Transmission Control Module (TCM) information on input shaft speed from the engine.
12. Speed sensor, output shaft (2) - Provides Transmission Control Module (TCM) information on output shaft speed from the transmission.
13. Oil temperature sensor (3) - Provides Transmission Control Module (TCM) information on transmission oil temperature.
14. Gear Selector Module (GSM) - Provides Transmission Control Module (TCM) information on Geartronic position and winter mode (W) etc.

see SYSTEM OVERVIEW

Scheme 20

Data from the siren (Siren Control Module) to the upper electronic module contains configuration and status information. This data is carried via serial communication.

When the alarm is activated the siren sends continuous status signals to the upper electronic module.

The siren is equipped with a battery and a built-in battery charger so that it is independent of the vehicle power supply. The battery charger maintains battery voltage in the integrated battery. When the alarm is activated the power supply is monitored for the siren and serial communication between the siren and the upper electronic module. The siren sounds if the car's power supply to the siren is broken or if communication between the upper electronic module and the siren is interrupted. The battery and the battery charger in the siren cannot be changed separately. The entire siren must be replaced if it is faulty.

The siren is located in a protected position under the fender liner in the front right-hand wheel arch. The siren must be configured after replacement. Configuration is carried out using VIDA (Volvo scan tool).

The siren can be diagnosed.

Scheme 21

The Sun Roof Module is operated by one switch. The switch is located in the same unit in the roof as the front reading lamps and the courtesy lighting. The sun roof can be opened, closed and tilted.

The sun roof is powered by a motor in the roof in front of the sun roof. The position of the sun roof is determined by two optical sensors.

There are diagnostics for the sun roof.

Scheme 22

The Mass Movement Sensor detects movement in the passenger compartment using radio waves at 2.450 GHz. The Doppler effect principle is used to determine if the frequency of the received microwave has been modified in comparison to the transmitted microwave. Any change in frequency is interpreted as a movement in the car. When movement is detected, a trigger signal is sent to the upper electronic module which activates the alarm.

The movement sensor is located in the headlining in the center of the car. This allows the sensor to cover as large an area as possible.

There are diagnostics for the movement sensor.

Scheme 23

The rain sensor module optically senses water on the windshield. An infra red beam of specific intensity lights a section of the windshield. The intensity of the reflected beam is measured and compared to the intensity of the transmitted beam. If there is water on the surface of the windshield, the beam distorts, reducing the intensity of the beam. If the beam is not reflected completely it is interpreted as rain on the windshield and the windshield wipers are started.

The signals from the upper electronic module are carried via serial communication. The rain sensor transmits the signals to the upper electronic module. These signals request a particular windshield wiper speed (depending on the amount of rain falling on the windshield), indicate that a sudden large splash has hit the windshield and register the light conditions outdoors.

The rain sensor is located in front of the rear view mirror on the inner side of the windshield. A special windshield is used on cars with rain sensors.

There are diagnostics for the rain sensor.

Scheme 24

There are a number of lamps inside the passenger compartment. The lamps include four reading lamps and a general courtesy lamp.

The front left and front right reading lamps and the courtesy light are located in the same unit in the roof, just above the rear view mirror. The two rear reading lamps are located in the roof above the rear seat.

The five lamps transmit control signals to the control module. These signals allow the control module to determine the status of the lamps and switches This allows faults such as broken bulbs, open circuits or jammed switches to be detected.

The five control signals are distributed as input signals at the four inputs in the upper electronic module. The control signal for the courtesy lighting shares the same inputs as control signals for the front reading lamps. The rear reading lamps each have their own input.

Two different lighting times can be programmed using VIDA depending on the requirements of the customer.

1. Short lighting time which is the time from when the door is unlocked or closed or from when the engine is switched off until the interior lighting goes out. The time can be set between 5 and 255 seconds. Normal setting is 30 seconds
2. Long lighting time, which is the time from when a door is left open or from when a light is lit using a button to when the interior lighting goes out. The time can be set between 0 and 255 minutes. Normal setting is 10 minutes.

There are diagnostics for all lamps in the inner roof lighting.

Scheme 25

The remote control can be used to lock and unlock the doors, unlock the tailgate (V70 and V70XC), open the trunk lid (S80 and S60), to activate the approach lighting, and to activate the panic alarm (certain markets).

The receiver for the remote control is located in the rear view mirror and transmits signals to the upper electronic module. These signals determine

1. which function should be activated
2. at which frequency the receiver receives the signal from the remote control
3. which of the remote controls transmitted the signal
4. the signal strength received from the remote control.

Up to six remote controls can be stored in the upper electronic module. The control module stores the identity and PIN for each remote control.

The remote control identity and PIN are also stored in the central Volvo database When replacing the upper electronic module, this data is transmitted to the car. This means that the remote controls do not need to be replaced and can be used with the new upper electronic module.

There are two different types of remote control, depending on whether the car is a late or an early model. The two variants are programmed into the control module in different ways. The early variant has an 8 digit PIN. The late variant has one 8 digit and one 16 digit PIN.

The early version and late version differ by chassis number.

1. (1); applies to cars manufactured in production plant 1
2. (2); applies to cars manufactured in production plant 2.

Information regarding at which production plant a car was manufactured can be found in the VIN number. The 7th character from the right in the VIN indicates the production plant.

If the seat and power door mirrors in the car have a memory function, these functions are affected by the remote controls which are stored in positions 1, 2 or 3. The memory functions store the seat and power door mirror settings at the time the car was locked using one of these remote controls. Next time the car is unlocked using the same remote control, the seat and the power door mirrors move to the same settings.

The remote control battery can be replaced.

Scheme 26

The rear view mirror has an automatic anti-dazzle function for when light from behind the car is too bright in the mirror (option in certain markets).

One photo sensor on the front of the rear view mirror, and one on the rear side compare light intensity. When the intensities differ by a specified amount the anti-dazzle function compensates to the required degree. The upper electronic module receives and manages the signals from the two photo sensors.

The anti-dazzle function can be set to the customer requirements. The selectable values are Light, Normal and Dark. Initial setting is Normal.

LEDs for the seat belt reminder are located in the rear view mirror, above the mirror lens.

There are diagnostics for the functions in the rear view mirror.

VIDA identifies control modules by reading off a number of codes from the control module memory.

The codes contain information about the control module

1. hardware P/N (control module without software)
2. hardware serial number (control module without software)
3. software P/N
4. diagnostic software P/N.