Electronics - Design and Function - 4 of 4: Other Volvo C70 II

SIGNALS

The following table summarizes the input signals to and output signals from the phone module (PHM). The signal types are divided into directly connected signals, MOST and CAN communication. The illustration below (Scheme 116) displays the same information with the Volvo component designations.

Scheme 116

Scheme 117

There are two different types of control panel

1. for power seats without memory
2. for power seats with memory.

Power seats without memory

In vehicles with power seats without memory, the control panel is directly connected to the motors and does not have a power seat module, left (PSL) and a power seat module, right (PSR).

Power seats with memory

In vehicles with power seats with memory, the control panel is integrated in the power seat module, left (PSL) and power seat module, right (PSR).

An easy way of differentiating between power seats with memory and power seats without memory is to look at the control panel. Seats without memory do not have memory buttons (1-3) or a programming button (MEM).

This information refers to seats with memory, power seat module, left (PSL) and power seat module, right (PSR), unless otherwise stated.

The controls are used to transmit input signals to the control module from the user

1. Runs each of the four motors in the direction required.
2. Memory buttons. Input signal indicating the position of the buttons (Memory 1, 2 and 3 and the programming button).

The control panel cannot be replaced separately, the entire control module must be replaced in the event of a fault.

There are diagnostics for the control panel.

ACTIVATING COMPONENTS AND FUNCTIONS

Use this option to activate components / functions in the power seat module, left (PSL) and power seat module, right (PSR).

READING OFF AND PROGRAMMING DATA

With this option it is possible to read programmed data and to program in data.

Note. If the control module has been replaced, the position of the seat must be initiated using a diagnostic function.

DOWNLOADING SOFTWARE AND REPLACING THE CONTROL MODULE

New software can be downloaded into the power seat module, left (PSL) and power seat module, right (PSR). When ordering software, the hardware and the software in the car is compared to the information in the Volvo central database. If the comparison is OK the software is downloaded to the control module.

If the comparison between the car and Volvo central database is not OK, the database is updated with the car configuration. New software is downloaded after the update is complete.

A control module may already have software installed which will result in incorrect information being updated in the Volvo Central Database. To avoid this, tick the box in the VIDA (Volvo scan tool) software manager indicating the hardware has been replaced when the control module has been replaced.

Note. If the control module has been replaced, the position of the seat must be initiated using a diagnostic function.

A number of customer parameters can be programmed into the power seat module, left (PSL) and the power seat module, right (PSR). These customer parameters are stored in the control module but not in the Volvo central database. This means that the customer parameters must be reprogrammed when hardware is replaced and when downloading software.

It is possible to reprogram the function so that the seat is automatically set by remote control. With this function activated the seat can be set using the remote control. This function is not available if it is deactivated.

Scheme 118

Programming

There are four buttons for programming seat positions

1. three memory buttons called 1, 2 and 3
2. a programming button, MEM.

To program in a new seat position

1. move the seat to the desired position
2. press MEM and one of the memory buttons at the same time.

Moving

To move the seat to the programmed position

1. press the desired memory button and hold it in until the seat stops.

The button must be kept depressed for the seat to move. The seat stops if the button is released.

The seat stops moving when the position of the seat matches the position programmed into the memory. If another button is pressed the seat will stop moving. The seat will not move if no position is programmed.

The vehicle has door mirrors with memory. When the desired memory button is pressed, the mirrors are set to the programmed position. Information is sent from the power seat module, left (PSL) (3/26) to the power seat module, right (PSR) (3/27) and driver door module (DDM) (3/127) to set the door mirrors to the programmed position. The memory positions of the door mirrors are stored in the driver's door module (DDM) (3/126) and passenger door module (PDM). The door mirror position stored is the position of the mirrors when the seat position was programmed. The position of the door mirror on the driver's side is stored in the driver door module (DDM). The position of the door mirror on the passenger side is stored in the passenger door module (PDM).

When the seat is run, a maximum of two motors are activated at the same time. If all motors need to operate to reach the programmed position, there is an order of priority. Motor 1 (front-rear adjustment) and motor 2 (backrest adjustment) operate first.

Each seat motor has a Hall sensor which detects the present position of the seat. When one of the stepper motors for the seat is run, the control module counts the number of pulses from the Hall sensor. The Hall sensor counts the number of revolutions made by the motor by detecting a magnet on the motor shaft. This creates a pulse for each revolution of the motor.

When a seat position is stored, the information about the number of pulses counted from each motor is stored in a memory.

When one of the memory buttons is pressed in, the control module calculates which motors need to be run and in which direction to obtain the desired position.

Scheme 119

On a power seat, the backrest can be adjusted, the seat height can be altered and the seat can be moved forwards or backwards. There are four motors for moving the seat. The control buttons are on the outside of the seat and are in the shape of a small seat and a small backrest. There are two control buttons on each control panel. The buttons are spring-loaded, so they must be held pressed in for the seat to move.

The seat can be operated

1. within 5 minutes of the door being opened
2. within 30 seconds of the door being closed
3. when the key is in position 0 or removed
4. with the ignition on.

Scheme 120

In power seat module, left (PSL) (3/26) and power seat module, right (PSR) (3/27) there are three memories, which store the seat positions for a maximum of 3 remote controls. There are also three further memory positions which can be stored from the control panel. The control module can store a total of six different memory positions.

Vehicles with power seats with memory have a personal setting function. Using this function, the positions of the door mirrors and seat can be stored individually for each remote control (a maximum of three remote controls, i. e. remote memory positions 1, 2 and 3).

The customer parameters in the power seat module, left (PSL) and power seat module, right (PSR) determine whether the remote memory for the seat is activated or not.

The remote control memory for the door mirrors can also be switched off. This is done using a customer parameter in the driver door module (DDM) (3/126) and passenger door module (PDM) (3/127). "Programming of the remote control settings" for seats and mirrors is carried out via VIDA (Volvo scan tool).

The signal from the remote control is transmitted to the central electronic module (CEM) (4/56) when the car is locked or unlocked. The central electronic module (CEM) also identifies which remote control is being used, stores this information and decides what information (see below) must be sent to

1. the power seat module, left (PSL) and power seat module, right (PSR)
2. driver door module (DDM)
3. passenger door module (PDM).

The central electronic module (CEM) transmits information about which remote control locked the vehicle and which remote control unlocked the vehicle. This information is transmitted when the door is opened.

The seat position is first stored when the door is opened after unlocking. If the remote control that unlocked the car is different from the one that locked it, the previous position is stored and the seat position for the remote control being used is retrieved and the seat adjusted accordingly. If the vehicle is locked with another remote control than that used to unlock it, no memory position is stored the next time the car is unlocked.

The remote memory positions for the door mirrors are stored for the driver door module (DDM) and passenger door module (PDM) in the following cases

1. when the key is removed from the ignition switch
2. when a new remote control is activated.

When the vehicle is unlocked, the power seat module, left (PSL) and power seat module, right (PSR) uses the information about which remote control unlocked the car. This is so that the correct remote memory position can be selected (i. e. the seat position last set by the driver for this remote control). When the door is opened the seat starts to move to the programmed remote memory position. The seat can be stopped by pressing one of the buttons on the control panel.

If the vehicle is opened with a key, the memory settings for the seat are not affected. Remote operation of the seat is not possible if the key is in the ignition switch.

In addition, when a door is open, it takes approximately 5 minutes before the power seat module, left (PSL) and power seat module, right (PSR) switch to sleep mode. If this occurs, and the customer then attempts to set a new seat position, the information about which remote control opened the door will have been lost and a new memory position will not be stored.

Scheme 121

Power seats without memory do not have memory management buttons. The seat motors can only be operated directly via the control panel. This type of seat does not have a power seat module, left (PSL) or a power seat module, right (PSR). The seat motors are directly connected to the control panel.

Scheme 122

The "easy-entry" function facilitates passenger entry to the vehicle's rear seats. This is operated using a switch that is located on the upper side's outer edge of the front seats. When using this function the motors are activated that control the movement of the seats, front-rear and up/down. The seat is then moved forwards and downwards to facilitate entry to the rear seats.

Scheme 123

The power seat module, left (PSL) and power seat module, right (PSR) manage the functions for

1. seat operation
2. storage of memory positions (seat positions only).

The control modules are located on the outside of the front seats and are integrated in the control panel. The side panels must be detached to replace the control modules.

The power seat module, left (PSL) and power seat module, right (PSR) communicate with both directly connected components and with other control modules via CAN communication.

The control modules check carried out activations and input and output signals via an integrated diagnostic system. A diagnostic trouble code (DTC) is stored in certain cases if the control modules detect a fault.

Any diagnostic trouble codes (DTCs) are stored in the control modules memory. The data can be read off using VIDA (Volvo scan tool).

A simple way to check that the power seat module, left (PSL) and power seat module, right (PSR) are supplied with power and grounded is to move the seat.

If the voltage is below 8.5 V or above 16.0 V, the power seat module, left (PSL) and power seat module, right (PSR) will not function. If the voltage increases to above 9.0 V or falls below 15.5 V, the control module will function again.

For further information, see SIGNALS .

The table below summarizes the input signals to and output signals from the power seat module, left (PSL) (3/26) and power seat module, right (PSR) (3/27). The signal types are divided into directly connected signals and CAN communication. The illustration below (Scheme 124) displays the same information with the Volvo component designations.

Scheme 124

Scheme 125

The system for digital radio reception consists of

1. antenna for digital satellite and terrestrial radio
2. Remote Digital Audio Receiver (RDAR)

The remote digital audio receiver (RDAR) has the task of receiving digital satellite and terrestrial radio signals. The remote digital audio receiver (RDAR) uses the signal that is the strongest at that instant.

Frequency range for radio reception

1. satellite transmitter 2320.0 - 2332.5 MHz
2. terrestrial 2324.2 - 2328.3 MHz

The quality of the sound does not deteriorate in the event of poor reception, the sound is switched off temporarily instead. For example, if the antenna is covered by a roof box.

A Volvo SIRIUS satellite radio subscription must be activated in order for the satellite radio to function. Activation is carried out by the customer ringing Sirius and giving the serial number of the Remote Digital Audio Receiver (RDAR). The serial number can be obtained in the display for the Infotainment module (ICM).

Scheme 126

The remote digital audio receiver (RDAR) has a corresponding antenna, which receives digital satellite and terrestrial radio signals. The antenna is directly connected to the remote digital audio receiver (RDAR). The antenna is mounted on the trunk lid of the C70.

There are diagnostics for the antenna.

READING OFF INPUT AND OUTPUT SIGNALS

This function can be used to continuously read off the values and status of the control module's input and output signals.

READING OFF EXTENDED FAULT-TRACING INFORMATION

This function can be used to read parameters, status identifiers and counters stored at the same time as a diagnostic trouble code (DTC). These are called frozen values.

Software can be downloaded to the Remote Digital Audio Receiver (RDAR). When software is ordered, the vehicle' software and hardware is compared to Volvo's central database. If they are compatible, the software is downloaded to the system.

If the comparison between the car and Volvo's central database does not correspond, then the database is updated with the vehicle's configuration. When this is complete the software is downloaded.

After replacing the control module the module's unique ID number must be programmed in the Central electronic module (CEM).

If a problem arises after software download and the control module does not work, try switching the ignition off and on.

Select the MOST network for a total download of software to the vehicle.

ACTIVATING A SIRIUS SATELLITE RADIO SUBSCRIPTION

A Volvo SIRIUS satellite radio subscription must be activated for a satellite radio to function.

Activation is carried out by the customer ringing Sirius and giving the serial number for the Remote Digital Audio Receiver (RDAR). The serial number can be obtained in the display for the infotainment control module (ICM).

Scheme 127

During radio reception, the digital radio signals are received by the antenna system and transmitted to the remote digital audio receiver (RDAR) (16/145) where they are decoded. The remote digital audio receiver (RDAR) then transmits the signals onwards via the MOST network to the infotainment control module(ICM) (16/1.2) and the integrated audio module (IAM) (16/1) or the audio module (AUD) (16/105) depending on the vehicle configuration.

Remote Digital Audio Receiver (RDAR) uses the signal, satellite or terrestrial, which is strongest at the time.

CONTROL MODULE

Remote Digital Audio Receiver (RDAR) has the task of receiving both digital satellite and terrestrial radio signals, process them and transmit them onward on the MOST network.

In C70, the remote digital audio receiver (RDAR) is located on the right side at the rear wheel housing above the global positioning system module (GPS).

The control module has serial optical communication with other components in the MOST network. This means that all communication with Remote Digital Audio Receiver (RDAR) occurs via the Infotainment control module (ICM) or on the initiative of the Infotainment control module (ICM).

The control module checks the input and output signals through an integrated diagnostic system.

The control module communicates with directly connected components, and via MOST communication.

Any diagnostic trouble codes are stored in the control module memory. The information can be read out via the data link connector in the vehicle.

For further information, see SIGNALS .

The table below summarizes the input signals to and output signals from the Remote Digital Audio Receiver (RDAR). The signal types are divided into directly connected signals and MOST communication. The illustration below (Scheme 128) displays the same information with the Volvo component designations.

Scheme 128

The system for digital radio reception consists of

1. antenna for digital satellite and terrestrial radio
2. Remote Digital Audio Receiver (RDAR)

The remote digital audio receiver (RDAR) has the task of receiving digital satellite and terrestrial radio signals. The remote digital audio receiver (RDAR) uses the signal that is the strongest at that instant.

Frequency range for radio reception

1. satellite transmitter 2320.0 - 2332.5 MHz
2. terrestrial 2324.2 - 2328.3 MHz

The quality of the sound does not deteriorate in the event of poor reception, the sound is switched off temporarily instead. For example, if the antenna is covered by a roof box.

A Volvo SIRIUS satellite radio subscription must be activated in order for the satellite radio to function. Activation is carried out by the customer ringing Sirius and giving the serial number of the Remote Digital Audio Receiver (RDAR). The serial number can be obtained in the display for the Infotainment module (ICM).

Scheme 129

The Remote Digital Audio Receiver (RDAR) has an antenna. The antenna receives digital satellite and terrestrial radio signals. The antenna is directly connected to the Remote Digital Audio Receiver (RDAR).

The antenna is mounted in the cargo compartment on C70.

There are diagnostics for the antenna.

This function can be used to continuously read off the values and status of the control module's input and output signals.

This function can be used to read parameters, status identifiers and counters stored at the same time as a diagnostic trouble code (DTC). These are called frozen values.

Software can be downloaded to the Remote Digital Audio Receiver (RDAR). When software is ordered, the vehicle' software and hardware is compared to Volvo's central database. If they are compatible, the software is downloaded to the system.

If the comparison between the car and Volvo's central database does not correspond, then the database is updated with the vehicle's configuration. When this is complete the software is downloaded.

After replacing the control module the module's unique ID number must be programmed in the Central electronic module (CEM).

If a problem arises after software download and the control module does not work, try switching the ignition off/on.

Select the MOST network for a total download of software to the vehicle.

A Volvo SIRIUS satellite radio subscription must be activated for a satellite radio to function.

Activation is carried out by the customer ringing Sirius and giving the serial number for the Remote Digital Audio Receiver (RDAR). The serial number can be obtained in the display for the infotainment control module (ICM).

Scheme 130

During radio reception, the digital radio signals are received by the antenna system and transmitted to the remote digital audio receiver (RDAR) (16/145) where they are decoded. The remote digital audio receiver (RDAR) then transmits the signals onwards via the MOST network to the infotainment control module(ICM) (3/281) and the integrated audio module (IAM) (16/1) or the audio module (AUD) (16/105) depending on the vehicle configuration.

Remote Digital Audio Receiver (RDAR) uses the signal, satellite or terrestrial, which is strongest at the time.

Remote Digital Audio Receiver (RDAR) has the task of receiving both digital satellite and terrestrial radio signals, process them and transmit them onward on the MOST network.

In C70, the remote digital audio receiver (RDAR) is located on the right side at the rear wheel housing above the global positioning system module (GPS).

The control module has serial optical communication with other components in the MOST network. This means that all communication with Remote Digital Audio Receiver (RDAR) occurs via the Infotainment control module (ICM) or on the initiative of the Infotainment control module (ICM).

The control module checks the input and output signals through an integrated diagnostic system.

The control module communicates with directly connected components, and via MOST communication.

Any diagnostic trouble codes are stored in the control module memory. The information can be read out via the data link connector in the vehicle.

For further information, see SIGNALS .

The table below summarizes the input signals to and output signals from the Remote Digital Audio Receiver (RDAR). The signal types are divided into directly connected signals and MOST communication. The illustration below (Scheme 131) displays the same information with the Volvo component designations.

Scheme 131

DOWNLOADING SOFTWARE

When software is to be downloaded to the vehicle there are a number of stages in the downloading procedure in VIDA (Volvo scan tool)

1. Preparations
2. Verification
3. Downloading
4. Diagnostic services
5. Confirmation
6. Completion

PREPARATIONS

The preparations involve, among others that the user shall ascertain that the communications tool is connected and that there is sufficient power supply to the vehicle. VIDA (Volvo scan tool) performs a check of the voltage level status and the ignition position.

VERIFICATION

During verification, VIDA (Volvo scan tool) compares the software, hardware and serial number in the vehicle with that supplied in the software package.

If verification is OK, VIDA continues with the download.

If verification is not OK, a mismatch adaptation will be made and the Volvo central database will be updated before downloading can be performed.

DOWNLOADING

All control modules are set to programming mode when software is to be downloaded to a control module. Any existing software in the control module is erased so this cannot affect the new software.

When erasure is complete the new software is downloaded. Once the download has been sent a reset command is sent to the vehicle.

CONFIRMATION

Confirmation involves a confirmation file containing the vehicle's new configuration being created and sent to the Volvo central database. This is to update the Volvo central database with the vehicle's latest status and so a mismatch adaptation is not performed with the next download.

COMPLETION

The software download is completed by erasing all diagnostic trouble codes (DTC) stored in the vehicle.

Note. The clock in the vehicle may stop while downloading some software. Check the clock in the vehicle after downloading and adjust if necessary.

INFORMATION

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 behavior 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.

ORDERING SOFTWARE PRODUCTS

Generally you can divide software downloading into two stages.

First a software product must be ordered and sent from the Volvo central database to the VIDA (Volvo scan tool) station. The software must then be downloaded from the VIDA station to the vehicle.

This section describes ordering of a software product.

Each Volvo spare part has a part number, this also applies to software products. A software product is listed in the spare parts catalogue in exactly the same way as any other part.

Ordering a software product is done as follows

The mechanic specifies which software product is to be ordered and to which vehicle (model and chassis number). This is either done from the spare parts catalogue (via the part number) or via the software tab in VIDA (via software product). Several software products can be ordered at the same time for the same vehicle.

When ordering upgrades no reading is done from the vehicle. VIDA presupposes that the vehicle and the Volvo central database correspond and the software package is supplied to the VIDA station. A verification to ensure that the vehicle and the Volvo central database correspond will be performed before downloading starts.

When ordering re-downloading, VIDA (Volvo scan tool) reads the hardware and serial number from the vehicle and update the Volvo central database with information. The software packages is then supplied to the VIDA station.

The system structure for software controls the content of the software package for the ordered software product. A check is made that the software is applicable for the vehicle in question. If the check is not approved, an error message is shown to the mechanic. The mechanic must assess what the error is and reorder the software once the error has been rectified.

When the software package has been supplied to the VIDA station downloading can begin.

SOFTWARE PRODUCTS

The following types of software products are available

1. Re-downloading
2. Upgrading
3. Total upgrading CAN/MOST
4. Add or remove functionality or accessories
5. Individual configuration

RE-DOWNLOADING

The software product re-downloading is used when a control module has been replaced. In order to obtain software that corresponds with the replaced control module the vehicle data is read when placing the order.

Diagnostic services are run after downloading when necessary (e. g. programming of code).

UPGRADING

Software product upgrading is used to upgrade the software in the control module when there has been a complaint and there is a solution available to correct the issue.

VIDA (Volvo scan tool) does not read the vehicle data on ordering as no hardware is to be replaced during an upgrade.

If the latest software is already installed in the control module, the software package is not put together, the user receives the message that the control module already contains the latest software.

TOTAL UPGRADING CAN/MOST

The software product total upgrade is used to upgrade the software in several control modules on the CAN or MOST network.

Total upgrade involves building a software package for the control modules needing upgraded software. It all the control modules already have the latest software, no software package is formed.

INDIVIDUAL CONFIGURATION

The software product individual configuration is used to replace the software in a control module, so it no longer corresponds with the System structure for software. The system product individual configuration is not included in the spare part catalogue in VIDA (Volvo scan tool).

If an individual configuration has previously been downloaded to the vehicle the mechanic receives a warning before this is replaced.

A list of software products for individual configuration is available in the Technical Journals.

THE VOLVO CENTRAL DATABASE

The Volvo central database contains information about all Volvo cars in the world from model year 1999.

This includes information about the vehicles configuration, i. e. how the car is equipped, where the car was built, the vehicle structure week and VIN number.

It also contains information about which control modules are installed in the vehicle as well as their hardware, software and serial number.

In the system structure for software, there are links between control modules and compatible software. The system structure of the software ensures that it is always the latest release of compatible software, which is included in the software package when ordering software re-downloading or upgrades.

REMOTE UNLOCKING

The vehicle can be unlocked remotely via the Volvo On Call service. If the keys have been locked in the car or lost, the customer can call a Volvo Service Center. The position of the vehicle is determined via the global positioning system module (GPS) in the Telematics system and is transmitted to the Volvo Service Center. The customer must provide a code to the Service Center, which then transmits a signal to the vehicle. This signal activates the central locking system for a certain amount of time. When instructed, the customer must activate the switch in the tailgate/trunk lid. If this is done, the car is unlocked.

The function is market dependent.

Scheme 132

Whether the automatic locking function is activated on delivery or not is market dependent. If this function is activated, the side doors lock when the speed exceeds 7 km/h (5 mph). All the doors must be closed, the engine running and the vehicle moving forward. The only exception is the tailgate/trunk lid which can be open. Information about whether the engine is running or not is transmitted by the engine control module (ECM) to the central electronic module (CEM). Indication about whether the engine is driving the car forwards is different in cars with automatic transmissions and manual transmissions. In vehicles with automatic transmissions, the position of the gear selector is received from the transmission control module (TCM). The gear selector must not be in the park (P) or neutral (N) position for automatic locking to function. In vehicles with manual transmissions, the brake control module (BCM) transmits information about vehicle speed to the central electronic module (CEM). The accelerator pedal (AP) must be partly pressed as well for automatic locking to take place.

The door can be unlocked again as normal with the central locking buttons.

Scheme 133

If the car is unlocked using the remote control or key and the side doors or trunk lid/tailgate are not opened within 2 minutes, the car will be locked automatically. Whether this function is activated on delivery or not depends on the market. This function can be activated later via VIDA (Volvo scan tool) or the infotainment control module (ICM).

"COMFORT" FUNCTIONS

The corresponding function (Comfort Opening) is available when unlocking the vehicle. If the central electronic module (CEM) receives repeated unlock signals, corresponding to a pressed unlock button for approximately 3 seconds, it will unlock all doors and open all windows and the sunroof.

The tables below summarize the input and output signals to the units in the central locking system. The signal types are divided into directly connected signals, serial communication and controller area network (CAN) communication.

CENTRAL ELECTRONIC MODULE (CEM) (4/56)

DRIVER DOOR MODULE (DDM) (3/126)

PASSENGER DOOR MODULE (PDM) (3/127)

DRIVER INFORMATION MODULE (DIM) (5/1)

PHONE MODULE (PHM) (16/60) (OPTION)

CONVERTIBLE ROOF MODULE (CRM) (4/59)

PHONE MODULE (PHM)

Phone module (PHM) (16/60) is an option. The phone module (PHM) communicates with the central electronic module (CEM) via the low speed side of the CAN network. If a phone module (PHM) is installed, the unit can be used for remote unlocking via the Volvo On Call service. This means that the vehicle can be unlocked from a Volvo Service Center.

The phone module (PHM) can also automatically transmit an emergency signal if one or more airbags have been triggered. The emergency signal is also transmitted if the "SOS" button is pressed.

Scheme 134

The customer can personalize some of the central locking settings using the infotainment control module (ICM) (16/1). The infotainment control module (ICM) communicates with the central electronic module (CEM) via the low speed side of the CAN network. The central locking settings are presented via a menu system in the display on the infotainment control module (ICM). For further information about the settings which can be made, see: DESCRIPTION OF PROGRAMMABLE PARAMETERS, CUSTOMER ADAPTATION

The central locking settings are stored in the central electronic module (CEM) and are transmitted to the infotainment control module (ICM) when the ignition is switched on.

Scheme 135

The switch for valet locking is at one edge of the glove compartment in the dashboard. The switch is directly connected to the central electronic module (CEM). The switch is affected after the glove compartment has been locked in the normal way using the key blade (turning 0 to 90 degrees) and then continuing to turn (from 90 to 180 degrees).

Valet locking also includes lockable storage compartments and the lock for the ski hatch.

Scheme 136

The switch for unlocking the fuel tank filler cover is on the light switch module (LSM) (3/111). The switch is directly connected to the central electronic module (CEM). The cover can be opened if the vehicle speed is below 7 km/h (5 mph).

For the American market, the function has a delay before the fuel tank filler cover can be opened. This is to allow for the cancellation of the automatic leak test and for the pressure in the tank to even out.

Scheme 137

The lock units (3/74-77) are in the doors and are directly connected to the door control module in the relevant door.

There are different versions of the lock units, depending on the configuration of the lock motors.

There are two versions of the lock units in the front doors with lock motors for

1. central locking
2. central locking and deadlocking.

The central locking lock motor locks the door.

The door control modules can only unlock the doors on receipt of a command from the central electronic module (CEM). In addition to the lock motors, the lock units contain up to three contract breakers depending on the configuration

1. contact breaker to indicate that the central locking motor is in the locked position
2. contact breaker to indicate that the door is in the latch position (not fully closed)

The lock motors have built in overheating protection which prevents the motor from activating if there is a risk of the motor getting too hot.

Scheme 138

In practice there is no "locked" position for the lock on the tailgate/trunk lid. The difference between locked and unlocked is whether the central electronic module (CEM) will activate the lock motor or not when the switch on the tailgate/trunk lid is pressed.

The tailgate/trunk lid is "locked" and "unlocked" at the same time as other doors if an unlock command is received from the remote control. The tailgate/trunk lid can also be unlocked separately using a dedicated button on the remote control.

For the C70, it is also possible to unlock and open the cargo compartment using a lock cylinder, which is located under the cup holder in the center console (model year 2006 and early 2007 versions). For the C70 (late versions 2007-), the lock cylinder is located on the left-hand front edge of the rear seat.

This lock is mechanically directly connected to the cargo compartment's locking mechanism.

The switch on the tailgate/trunk lid and lock motor (3/78) is directly connected to the central electronic module (CEM).

Scheme 139

The remote control is used to activate function in the system remotely. The basic functions of the remote control are

1. unlocking and locking the side doors
2. unlocking the trunk lid/tailgate
3. activating the local lighting
4. activating alarm functions
5. for the C70: unlocking and locking the storage compartment and ski hatch.

The remote control has a built-in communication circuit and a memory. A coded signal is sent when a button on the remote control is pressed. This signal is received by the remote control receiver and forwarded to the central electronic module (CEM). For the remote control to work with the system, a unique code in the remote control must be learned by the central electronic module (CEM). This takes place during installation at the factory.

The remote control has a key blade which is normally retracted inside the remote control. The key blade can be used in emergency situations to unlock the driver's door. This does not disarm alarm functions however, so should only be used as a last resort to open the car.

The remote control has an integrated battery which is used when commands are sent to the system. This battery must be replaced regularly. The remote control contains an internal voltmeter that measures the voltage of the internal battery. If the battery voltage is low, this information is transmitted in the messages transmitted to the Remote Receiver Module (RRX). The Central electronic module (CEM) receives this information and transmits a message via the CAN network to the Driver information module (DIM), which, in such cases, displays a message that the voltage for the remote control is low. Reduced remote control range is also an indication that the battery charge is low.

Note. It has been shown that in some cases there is a system function fault when communication between the Remote Receiver Module (RRX) and the ignition key are affected for different reasons. The function fault is not due to any electrical fault and no diagnostic trouble codes (DTCs) are stored either.

Due to increased external radiation, for example from TV/radio transmitters and mobile telephones, the signal from the remote control can, on rare occasions, be jammed. This is a rare fault but it can occur, especially in places where different external signals can impair transmitting and reception conditions. This is not only associated with the central locking system but can also affect different types of wireless communication.

Scheme 140

The remote receiver module (RRX) is on the top of the driver information module (DIM).

The remote receiver module (RRX) is connected to the central electronic module (CEM) via serial communication (LIN). The remote receiver module (RRX) receives the signals transmitted from the remote control and forwards them to the central electronic module (CEM). When a key is in the ignition switch, the Central electronic module (CEM) ignores all messages from the Remote Receiver Module (RRX). This prevents the central locking system from unlocking if a button on the remote control is unintentionally pressed in.

The remote receiver module (RRX) checks for a signal from a remote control 4 times per second.

The receiver is powered by the central electronic module (CEM) and grounded in the right-hand A-post.

Scheme 141

The vehicle is equipped with an electric lock for the ski hatch to prevent access to the cargo compartment when the roof is open. Locking/unlocking of the ski hatch is controlled by the Convertible Roof Module (CRM) (4/59).

Scheme 142

The vehicle can be equipped with 4 electrically lockable compartments. Two compartments are located in each door and two compartments are in each side of the rear seat. The compartments are locked and unlocked at the same time as the ski hatch lock and are controlled by the Convertible Roof Module (CRM).

Scheme 143

The central locking system contains a number of functions. The system is monitored by the central electronic module (CEM). The central electronic module (CEM) communicates with the constituent units, whether directly connected or connected in series, via the CAN network.

The functions covered are

1. standard locking function (total or 2 stage)
2. deadlocking
3. private locking mode
4. unlocking the trunk lid/tailgate
5. unlocking the fuel tank filler cover
6. light functions (local lighting and approach lights)
7. indication of the status of the doors and hatches
8. remote unlocking
9. automatic locking function
10. re-locking
11. lockable storage compartment (option C70)
12. lock for ski hatch (C70).

STANDARD LOCKING FUNCTION

The standard locking function unlocks the side doors and activates the lock button so that the tailgate/trunk lid can be opened. On the C70 it also unlocks the storage compartments and the lock for the ski hatch. There are two settings

1. total
2. 2 stage.

Total unlocking unlocks all doors at the same time. 2 stage locking unlocks the driver's door first and then the other doors. The driver's door unlocks on the first press of the unlock button on the remote control. On the C70 the storage compartments and ski hatch unlock as well. Press the button again within 10 seconds and the other doors unlock.

DEADLOCK

Deadlocking is an option. Deadlocking means that the inner door handles and lock buttons are disengaged. It will not then be possible to open a side door from the inside, even if a window is smashed. Deadlocking is activated 25 seconds after the vehicle was locked. The function can be disengaged using the switch for reduced alarm.

VALET LOCKING MODE

The glove compartment and cargo compartment can be locked to "valet' mode. On the C70, the storage compartments and the ski hatch lock also have the valet mode function. This function is used to block access to these compartments when, for example, leaving the car for a service when there are personal belongings left in the car or when the roof is left open (applies to the C70) when parked.

UNLOCKING THE TRUNK LID/TAILGATE

In practice there is no "locked" mode for the lock on the tailgate/trunk lid. The difference between locked and unlocked is whether the central electronic module (CEM) will activate the lock motor or not when the switch on the tailgate/trunk lid is pressed.

The tailgate/trunk lid is "locked" and "unlocked" at the same time as other doors if an unlock command is received from the remote control. The tailgate/trunk lid can also be unlocked separately using a dedicated button on the remote control.

The switch on the tailgate/trunk lid and the lock motor are directly connected to the central electronic module (CEM).

For the C70 (model year 2006 and early 2007 versions), the following applies

To access the cargo compartment when, for example, the vehicle has no power, there is a lock cylinder under the CD compartment in the center console, which is mechanically connected to the cargo compartment lock.

For the C70 (late versions 2007-), the following applies

To access the cargo compartment when, for example, the vehicle has no power, there is a lock cylinder on the left-hand side front edge of the rear seat, which is mechanically connected to the cargo compartment lock.

UNLOCKING THE FUEL TANK FILLER COVER

The unlocking switch for the fuel tank filler cover is on the light switch module (LSM) to the left of the driver. The button is directly connected to the central electronic module (CEM). The lock motor for the fuel tank filler cover is at the rear edge of the fuel tank filler cover. The lock motor is directly connected to the central electronic module (CEM).

LIGHT FUNCTIONS

Local lighting and approach lights are part of the system.

Local lighting is activated using the remote control. Approach lights are activated when the high/low beam switch is pulled backwards.

SWITCHES FOR DOORS, TAILGATE/TRUNK LID AND HOOD

There are switches at the side doors and tailgate/trunk lid which indicate whether the door is open or closed. There is also a switch at the hood if the car has an alarm. There is no switch at the fuel tank filler cover. The switches are closed when the door is closed, providing a ground connection to the central electronic module (CEM).

AUTOMATIC LOCKING

The system can be activated so that the car is locked automatically when the car reaches 7 km/h (5 mph). Whether this function is activated on delivery or not depends on the market.

RE-LOCKING

The system has a function for re-locking. If the car is unlocked using the remote control or key and the side doors or trunk lid/tailgate are not opened within 2 minutes, the car will be locked automatically. This function prevents the car from being left unlocked unintentionally.

TEXT MESSAGE FOR THE LOCK SYSTEM

The text message display in the driver information module (DIM) indicates whether child-proof locking, valet locking or reduced alarm is activated. There is also an alert message if a door opens while driving.

CUSTOMER SETTINGS

The customer can make certain settings to determine how the locking system works. For more information, see: DESCRIPTION OF PROGRAMMABLE PARAMETERS, CUSTOMER ADAPTATION

ACKNOWLEDGMENTS

The turn signal lamps give a long flash to confirm that the car is fully locked. They flash twice when the car is unlocked. The customer can decide whether the acknowledgment is activated or not via the menu system in the infotainment control module (ICM).

REMOTE CONTROL

The central locking system can be unlocked using the remote control.

The remote control has buttons for

1. unlocking
2. locking
3. unlocking the trunk lid/tailgate
4. panic function
5. local lighting.

PANIC FUNCTION

The panic function activates the horn for 25 seconds. This function is to attract attention in an emergency situation.

UNLOCKING USING THE KEY

The driver's door (also the passenger doors and cargo compartment on the C70) can be locked and unlocked using the key blade in the remote control. This is an extra solution should there be a fault in the system. The other doors can be unlocked using the inner central locking buttons after the key is inserted in the ignition.

LOCAL LOCKING (C70)

Usually there are locking buttons in the doors, but the C70 does not have these. The vehicle is equipped with LEDs instead that indicate whether the vehicle is locked or not. The LEDs light for approximately 5 minutes after locking the vehicle. The LEDs are on each door.

The Volvo On Call service can unlock the vehicle from the Volvo Service Center.

PRIVATE LOCKING

The private locking function prevents entry to certain areas and functions in the vehicle.

The key blade must be taken out of the remote control to activate this function. The function is activated by locking the glove compartment in the normal way using the key blade (turning 0 to 90 degrees) and then continuing to turn (from 90 to 180 degrees). This sets the glove compartment and trunk lid to valet mode and blocks outgoing calls on the phone module (PHM) if installed. On the C70, the ski hatch and the lockable storage compartments are also locked. A text message in the driver information module (DIM) indicates that the lock is active. The trunk lid cannot now be opened using the remote control or lock switches in the doors. The key blade is kept by the customer and the remote control can be handed to valet parking attendants or workshop staff who need access to the vehicle.

There are two lock cylinders by the lock mechanism for the rear seat backrests to ensure the degree of security required. These lock cylinders can be locked or unlocked using the key blade. There is no electrical indication that these locks are locked. The customer must check this themselves.

This function is deactivated by inserting the key blade in the lock cylinder in the glove compartment and turning it back a quarter of a turn (from 180 to 90 degrees). The trunk lid can then be opened using the remote control or central locking button.

Scheme 144

Tailgate/trunk lid can be opened using the switch on the tailgate/trunk lid.

The lock motor for the tailgate/trunk lid and switch is directly connected to the central electronic module (CEM). When the switch is affected, the central electronic module (CEM) checks the status of the lock system and activates the lock motor if opening is permitted. The tailgate/trunk lid does not open if the vehicle speed is higher than 7 km/h (5 mph) or if privacy locking is activated.

There is no "unlocked" position for the lock motor for the tailgate/trunk lid. When the motor is activated, it releases the catch in the body and the tailgate/trunk lid can be opened. The tailgate/trunk lid locks when it is closed again.

When the tailgate/trunk lid is to opened, the lock motor is powered for approximately 0.7 seconds or until the central electronic module (CEM) receives a signal from the indicator that it is open. If the trunk lid/tailgate is not indicated as open during this time, a diagnostic trouble code (DTC) is stored in the central electronic module (CEM).

The tailgate/trunk lid can be opened by activating the button on the remote control even if the rest of the vehicle is locked.

Scheme 145

The switch for unlocking the fuel tank filler cover is in the light switch module (LSM). The switch and lock motor are directly connected to the central electronic module (CEM). If the switch is affected, the central electronic module (CEM) is grounded and powers the lock motor which begins to function. The lock motor has a spring-loaded piston which returns to its original position after a fully completed cycle. This means that the lock motor only needs to operate in one direction.

If the function for automatic detection of fuel leakage is installed, there may be a delay of up to 1.5 seconds before the filler cover opens. This is so that the fuel tank has time to release the overpressure before the filler cover is opened. This function is only available on the American market.

The interior lighting is checked by the central electronic module (CEM). The interior lighting comes on when the vehicle is unlocked.

There are also functions for external lights

1. approach lighting
2. approach lights.

Local lighting

Local lighting is activated using the remote control. The following light when activated

1. interior lighting
2. parking lights
3. license plate lighting
4. door mirror lighting (option).

The default setting is for the lighting to be on for 30 seconds or until the key is turned in the ignition switch. This time can be adapted to the wishes of the customer.

Approach lights

There is a function for approach lights as part of the lighting system. When the engine is off, the key is removed from the ignition and the dip switch is activated, the following lights

1. low beam
2. parking lights
3. fog lamps
4. interior lighting.

The default setting for the lighting is 30 seconds. This time can be adapted to the wishes of the customer.

Customer settings

The duration that the local lighting and approach lights are on can be adapted to the wishes of the customer.

For information about customer adaptations, see: DESCRIPTION OF PROGRAMMABLE PARAMETERS, CUSTOMER ADAPTATION

Scheme 146

There are two contact breakers in the lock units in the side doors

1. contact breaker to indicate if the door is ajar (not fully closed)
2. contact breaker to indicate that the central locking motor is in the locked position.

The contact breaker which indicates if the door is ajar is directly connected to the central electronic module (CEM) from all doors.

The signals are used to generate error messages and diagnostic trouble codes (DTCs) if a door is not properly closed when the vehicle is driven or if locking or unlocking of one or more doors has failed one or more times.

There is only one contact breaker in the lock unit in the tailgate/trunk lid. This indicates whether the tailgate/trunk lid is open or closed.

For the C70 there is a LED in each door to indicate when the door is locked or unlocked. The LEDs are used instead of the traditional lock buttons on top of the doors. The LEDs flash for a short time after the doors have been locked or unlocked.

The vehicle can be unlocked at a distance via the service Volvo On Call.

If the keys have been locked in the vehicle or lost, the customer can call a Volvo Service Center. The vehicle's position is determined via Multimedia module (MMM) in the Telematic system and is sent to Volvo Service Center.

The customer states a code to the Service Center, which then sends a signal to the vehicle. This signal activates the central locking system for a time and on a given command the customer has to activate the switch in the tailgate. If this is done, the vehicle is unlocked.

The function is market dependent.

Scheme 147

Whether the automatic locking function is activated on delivery or not is market dependent. If this function is activated, the side doors lock when the speed exceeds 7 km/h (5 mph). All the doors must be closed, the engine running and the vehicle moving forward. The only exception is the tailgate/trunk lid which can be open. Information about whether the engine is running or not is transmitted by the engine control module (ECM) to the central electronic module (CEM). Indication about whether the engine is driving the car forwards is different in cars with automatic transmissions and manual transmissions. In vehicles with automatic transmissions, the position of the gear selector is received from the transmission control module (TCM). The gear selector must not be in the park (P) or neutral (N) position for automatic locking to function. In vehicles with manual transmissions, the brake control module (BCM) transmits information about vehicle speed to the central electronic module (CEM). The accelerator pedal (AP) must be partly pressed as well for automatic locking to take place.

The door can be unlocked again as normal with the central locking buttons.

Scheme 148

If the car is unlocked using the remote control or key and the side doors or trunk lid/tailgate are not opened within 2 minutes, the car will be locked automatically. Whether this function is activated on delivery or not depends on the market. This function can be activated later via VIDA (Volvo scan tool) or the infotainment control module (ICM).

HINT: Comfort Closing is not available in C70, only Comfort Opening.

The Comfort Closing function can be activated from the remote control. If the central electronic module (CEM) receives repeated lock signals, corresponding to a pressed lock button for approximately 2 seconds, it will lock all doors and close the windows and sunroof.

The corresponding function (Comfort Opening) is available when unlocking the vehicle. If the central electronic module (CEM) receives repeated unlock signals, corresponding to a pressed unlock button for approximately 3 seconds, it will unlock all doors and open all windows and the sunroof.

The tables below summarize the input and output signals to the units in the central locking system. The signal types are divided into directly connected signals, serial communication and controller area network (CAN) communication.

CENTRAL ELECTRONIC MODULE (CEM) (4/56)

DRIVER DOOR MODULE (DDM) (3/126)

PASSENGER DOOR MODULE (PDM) (3/127)

DRIVER INFORMATION MODULE (DIM) (5/1)

PHONE MODULE (PHM) (16/60) (OPTION)

CONVERTIBLE ROOF MODULE (CRM) (4/59)

LOCK MOTOR TAILGATE/TRUNK LID

In practice there is no "locked" position for the lock on the tailgate/trunk lid. The difference between locked and unlocked is whether the central electronic module (CEM) will activate the lock motor or not when the switch on the tailgate/trunk lid is pressed.

The tailgate/trunk lid is "locked" and "unlocked" at the same time as other doors if an unlock command is received from the remote control. The tailgate/trunk lid can also be unlocked separately using a dedicated button on the remote control.

For C70 it is also possible to unlock and open the tailgate using a lock cylinder which is located on the rear seat's left leading edge.

This lock is mechanically directly connected to the cargo compartment's locking mechanism.

The switch on the tailgate/trunk lid and lock motor (3/78) is directly connected to the central electronic module (CEM).

Scheme 149

The remote control is used to activate function in the system remotely. The basic functions of the remote control are

1. unlocking and locking the side doors
2. unlocking the trunk lid/tailgate
3. activating the local lighting
4. activating alarm functions
5. for the C70: unlocking and locking the storage compartment and ski hatch.

The remote control has a built-in communication circuit and a memory. A coded signal is sent when a button on the remote control is pressed. This signal is received by the remote receiver (RRX) and forwarded to the central electronic module (CEM). For the remote control to work with the system, a unique code in the remote control must be learned by the central electronic module (CEM). This takes place during installation at the factory.

The remote control has a key blade which is normally retracted inside the remote control. The key blade can be used in emergency situations to unlock the driver's door. This does not disarm alarm functions however, so should only be used as a last resort to open the car.

The remote control has an integrated battery which is used when commands are sent to the system. This battery must be replaced regularly. The remote control contains an internal voltmeter that measures the voltage of the internal battery. If the battery voltage is low, this information is transmitted in the messages transmitted to the Remote Receiver Module (RRX). The Central electronic module (CEM) receives this information and transmits a message via the CAN network to the Driver information module (DIM), which, in such cases, displays a message that the voltage for the remote control is low. Reduced remote control range is also an indication that the battery charge is low.

Note. It has been shown that in some cases there is a system function fault when communication between the Remote Receiver Module (RRX) and the ignition key are affected for different reasons. The function fault is not due to any electrical fault and no diagnostic trouble codes (DTCs) are stored either.

Due to increased external radiation, for example from TV/radio transmitters and mobile telephones, the signal from the remote control can, on rare occasions, be jammed. This is a rare fault but it can occur, especially in places where different external signals can impair transmitting and reception conditions. This is not only associated with the central locking system but can also affect different types of wireless communication.

Scheme 150

Remote Receiver Module (RRX) is located up at the headlining, to the left of the front lighting panel.

Remote Receiver Module (RRX) receives signals sent from the remote control and transmits them on to Central electronic module (CEM) via serial communication (ISO).

When a key is in the ignition the Central electronic module (CEM) ignores all messages that come from the Remote Receiver Module (RRX). This is so that, e. g., the central locking system will not be locked if a button on the remote control is pushed accidentally.

The remote receiver checks for a signal from a remote control 4 times a second.

Remote Receiver Module (RRX) is supplied with voltage directly via 30-feed and is grounded in the A-pillar.

LOCKABLE SKI HATCH (ONLY C70)

The vehicle is equipped with an electric lock for the ski hatch to prevent access to the cargo compartment when the roof is open. Locking/unlocking of the ski hatch is controlled by the Convertible Roof Module (CRM) (4/59).

LOCKABLE STORAGE COMPARTMENT (ONLY C70) (OPTION)

The vehicle can be equipped with 4 electrically lockable compartments. Two compartments are located in each door and two compartments are in each side of the rear seat. The compartments are locked and unlocked at the same time as the ski hatch lock and are controlled by the Convertible Roof Module (CRM).

Scheme 151

The central locking system contains a number of functions. The system is monitored by the central electronic module (CEM). The central electronic module (CEM) communicates with the constituent units, whether directly connected or connected in series, via the CAN network.

The functions covered are

1. standard locking function (total or 2 stage)
2. deadlocking
3. private locking mode
4. unlocking the trunk lid/tailgate
5. unlocking the fuel tank filler cover
6. light functions (local lighting and approach lights)
7. indication of the status of the doors and hatches
8. remote unlocking
9. automatic locking function
10. re-locking
11. lockable storage compartment (option C70)
12. lock for ski hatch (C70).

The standard locking function unlocks the side doors and activates the lock button so that the tailgate/trunk lid can be opened. On the C70 it also unlocks the storage compartments and the lock for the ski hatch. There are two settings

1. total
2. 2 stage.

Total unlocking unlocks all doors at the same time. 2 stage locking unlocks the driver's door first and then the other doors. The driver's door unlocks on the first press of the unlock button on the remote control. On the C70 the storage compartments and ski hatch unlock as well. Press the button again within 10 seconds and the other doors unlock.

Deadlocking is an option. Deadlocking means that the inner door handles and lock buttons are disengaged. It will not then be possible to open a side door from the inside, even if a window is smashed. Deadlocking is activated 25 seconds after the vehicle was locked. The function can be disengaged using the switch for reduced alarm.

The glove compartment and cargo compartment can be locked to "valet' mode. On the C70, the storage compartments and the ski hatch lock also have the valet mode function. This function is used to block access to these compartments when, for example, leaving the car for a service when there are personal belongings left in the car or when the roof is left open when parked.

In practice there is no "locked" mode for the lock on the tailgate/trunk lid. The difference between locked and unlocked is whether the central electronic module (CEM) will activate the lock motor or not when the switch on the tailgate/trunk lid is pressed.

The tailgate/trunk lid is "locked" and "unlocked" at the same time as other doors if an unlock command is received from the remote control. The tailgate/trunk lid can also be unlocked separately using a dedicated button on the remote control.

The switch on the tailgate/trunk lid and the lock motor are directly connected to the central electronic module (CEM).

To access the cargo compartment when, for example, the vehicle has no power, there is a lock cylinder on the left-hand side front edge of the rear seat, which is mechanically connected to the cargo compartment lock.

The unlocking switch for the fuel tank filler cover is on the light switch module (LSM) to the left of the driver. The button is directly connected to the central electronic module (CEM). The lock motor for the fuel tank filler cover is at the rear edge of the fuel tank filler cover. The lock motor is directly connected to the central electronic module (CEM).

Local lighting and approach lights are part of the system.

Local lighting is activated using the remote control. Approach lights are activated when the high/low beam switch is pulled backwards.

There are switches at the side doors and tailgate/trunk lid which indicate whether the door is open or closed. There is also a switch at the hood if the car has an alarm. There is no switch at the fuel tank filler cover. The switches are closed when the door is closed, providing a ground connection to the central electronic module (CEM).

The system can be activated so that the car is locked automatically when the car reaches 7 km/h (5 mph). Whether this function is activated on delivery or not depends on the market.

The system has a function for re-locking. If the car is unlocked using the remote control or key and the side doors or trunk lid/tailgate are not opened within 2 minutes, the car will be locked automatically. This function prevents the car from being left unlocked unintentionally.

The text message display in the driver information module (DIM) indicates whether child-proof locking, valet locking or reduced alarm is activated. There is also an alert message if a door opens while driving.

The customer can make certain settings to determine how the locking system works. For more information, see: DESCRIPTION OF PROGRAMMABLE PARAMETERS, CUSTOMER ADAPTATION

The turn signal lamps give a long flash to confirm that the car is fully locked. They flash twice when the car is unlocked. The customer can decide whether the acknowledgment is activated or not via the menu system in the infotainment control module (ICM).

The central locking system can be unlocked using the remote control.

The remote control has buttons for

1. unlocking
2. locking
3. unlocking the trunk lid/tailgate
4. panic function
5. local lighting.

The panic function activates the horn for 25 seconds. This function is to attract attention in an emergency situation.

The driver's door (also the passenger doors and cargo compartment on the C70) can be locked and unlocked using the key blade in the remote control. This is an extra solution should there be a fault in the system. The other doors can be unlocked using the inner central locking buttons after the key is inserted in the ignition.

LOCAL LOCKING

Usually there are locking buttons in the doors, but the C70 does not have these. The vehicle is equipped with LEDs instead that indicate whether the vehicle is locked or not. The LEDs light for approximately 5 minutes after locking the vehicle. The LEDs are on each door.

The Volvo On Call service can unlock the vehicle from the Volvo Service Center.

Scheme 152

The starter motor consists of

1. Drive cover
2. Gear wheel
3. Solenoid magnet
4. Battery terminal
5. Rear end and bearing
6. Carbon brush holder and carbon brushes
7. Commutator
8. Armature
9. Permanent magnet
10. Armature housing
11. Planetary train
12. Lever with free rotating clutch
13. Pinion engaging drive.

Scheme 153

Starter motor terminals

1. 6/25:1 From the battery positive terminal
2. 6/25:2 From starter motor relay.

Ground terminal via transmission / cylinder block.

Scheme 154

The starter motor is a DC motor which uses a permanent magnet. This type of motor operates following the principle that the same poles (North/North) are forced away from each other and opposite poles (North/South) are drawn to each other.

Scheme 155

The control solenoid has two functions. The first is to mechanically engage the pinion in the flange/flywheel gear collar. The other is to function as a relay and to handle the greater current required to drive the starter motor when the pinion engages with the gear collar.

The control solenoid consists of the following components

1. Moving steel cores. Moved by pull-in winding in the solenoid, slides the pinion into position and moves the moving switch towards the fixed switches
2. Pull-in winding. Pull in the moving steel core. Disconnects when the moving steel core reaches the bottom position
3. Hold-in winding. Holds the moving steel core in position for as long as the solenoid is powered
4. Fixed steel cores. Stop position for the moving steel core
5. Contact spring
6. Fixed contacts. Closes when the moving switches reach the fixed switches
7. Terminals. Two, one for the battery and one for the DC motor
8. Moving switch. Switch which closes the fixed switches
9. Moving shaft. Affected by the moving steel core and connects the moving switches with the fixed switches
10. Return spring. Resets the control solenoid components to the rest position when the starter motor relay is disconnected.

Scheme 156

Functions as a one way clutch (freewheel). The freewheel allows the starter motor to drive the car engine, but not the other way around. This prevents the starter motor from being over-revved. This is carried out by spring-loaded rollers which lock the pinion and gear together when the starter motor operates.

The car engine cannot drive the starter motor because the pinion would turn in the rollers.

The freewheel clutch is attached to the armature shaft by spiral splines, which facilitate engagement and disengagement of the carrier plate/flywheel ring gear.

The example shown in the left-side of the illustration displays the normal position. The starter motor, connected to the outer section drives the pinion (inner section) by means of the rollers, which then lock.

The example shown in the right-side of the illustration displays what happens when the starter motor remains connected when the engine is started. The pinion (inner section) cannot drive the starter motor (outer section) because the rollers disengage.

Scheme 157

The planetary train is used to reduce the rotational speed of the pinion gear in relation to the speed of the armature and to increase the torque of the pinion.

The planetary train consists of

1. Pinion shaft with splines
2. Ring gear (fixed section)
3. Planetary gear (connected to the pinion shaft)
4. Sun gear (connected to the rotor)
5. Armature
6. Commutator.

Scheme 158

When the ignition key is turned to position III, the starter motor relay (2/35) receives power at terminal 86. If the immobilizer check is OK, then the engine control module (ECM) grounds the relay at terminal 85 and the relay is activated. Control solenoid terminal 6/25:2 is powered from relay terminal 87. This creates a magnetic field in hold-in and pull-in winding. This moves the moving steel core. When the core shifts a lever, fixed in the end of the core, presses the starter motor pinion to engage in the ring gear on the flywheel/flange.

The pull-in winding is grounded through the rotor and carbon brushes. This ground connection is lost when the moving switches close the circuit and the current passes from the solenoid to the starter motor.

Scheme 159

When the starter motor rotates, the sun wheel rotates clockwise. The planetary gears, which are constantly engaged with the sun wheel and ring wheel, rotate counter-clockwise. As the ring wheel is secured, the planetary gears are forced to circle around the sun wheel clockwise. The planetary gears rotate more slowly than the sun wheel. It is the clockwise rotation of the planetary gears which drives the pinion. The speed reduction that occurs between the sun gear and the planetary gear, results in greater torque. This means that a smaller and lighter starter motor can be used.

Scheme 160

When the moving steel cores for the solenoids reach their limit position the moving switches break the circuit with the fixes switches and the pull-in winding is disconnected. The hold-in winding keeps the switches closed. The current now passes through the positive carbon brushes and the armature winding. Grounding is carried out through the negative carbon brushes. This current creates a magnetic field in the rotor, which starts the rotor rotating. When the rotor rotates, the magnetic field is generated continuously depending on how the commutator and the windings are organized on the rotor. This allows the rotor to continue rotating.

When the ignition key is released the starter motor relay is deactivated and the circuit for the hold in winding is broken. Then the return spring for the solenoid pulls the pinion back, at the same time as the fixed and moving switches separate and the current to the starter motor is broken.

Scheme 161

This documents describes the principles of starter motor, irrespective of the make.

The purpose of the starter motor (6/25) is to turn the engine at start-up. The starter motor is positioned on the cylinder block side towards the transmission. A solenoid forces a pinion to engage with the gear ring on the flywheel / carrier plate of the engine. When the engine starts and the engine speed exceeds the starter motor speed, the pinion disengages. This prevents the starter motor over-revving.

This type of starter motor is equipped with permanent magnets instead of field winding.

The starter motor gives the greatest torque at low RPM at the same time as the voltage flow through the starter motor is greatest.

Note. The engagement time for the starter motor must not exceed 20-30seconds. Longer engagement time may result in the starter motor overheating and becoming damaged.

A starter motor relay (2/35) controls the starter motor solenoid. The ignition switch (3/1) and engine control module (ECM) (4/46) control the relay. The ignition switch powers the relay and the engine control module (ECM) grounds it.

On vehicles with four-cylinder engines and automatic transmissions the starter motor relay is controlled by both the ignition switch (3/1) and Engine control module (ECM) (4/46), where the ignition voltage feeds the relay and Engine control module (ECM) grounds the relay when the gear selector is in position P or N. When the gear selector is in position N it is also required that the brake pedal is depressed.

Scheme 162

Steering wheel angle sensor is integrated in the SRS-contact reel, which in turn is integrated in the Steering wheel module (SWM).

For Steering wheel module (SWM) with more functionality the steering wheel angle sensor, up to and incl. model year 2007, features a disc with code groove.

A circuit with light-emitting diodes read off the code groove and measures the steering wheel angle during one revolution. The steering wheel angle sensor also measures the current number of steering wheel revolutions using an analogue magnet-resistive sensor. By comparing the different sensors' signals, the control module can decide the exact steering wheel angle. Diagnostic trouble code is generated at ± 2.0 revolutions.

From and incl model year 2008 the disc with code groove was replaced with another analogue magnet-resistive sensor. However, the comparison between sensors takes place in a similar way.

The steering wheel angle sensor gives the Brake control module (BCM) information about the steering wheel speed among other things. Information about the steering wheel speed is also used by the Electrical power steering module (EPS).

Steering wheel module (SWM) with less functionality is only equipped with the analog magnet-resistive sensor that provides the Electrical power steering module (EPS) with information about the steering wheel angle speed.

The Electrical power steering module (EPS) uses the information about the steering wheel angle speed to provide the correct pump pressure for the steering function. As a result, the steering wheel module (SWM) is critical to safety.

It is important that the steering wheel angle sensor is correctly installed and that only Volvo original steering wheels are used.

When replacing the steering wheel, the instructions supplied must be followed to ensure that the 0 position of the steering wheel angle sensor is correctly calibrated.

Scheme 163

The steering wheel buttons control functions and menu selection for

1. traffic information (RTI) (option)
2. audio (option)
3. carphone (option)
4. bluetooth (option)
5. cruise control (option).

The signals from the steering wheel switch left (SWSL) and steering wheel switch right (SWSR) is transmitted via LIN communication.

The steering wheel buttons are connected to the steering wheel module (SWM) via contact reel in the steering wheel hub.

There are diagnostics for the steering wheel buttons.

Scheme 164

The steering wheel control stalks are directly connected to the steering wheel module (SWM).

The right-hand control stalk controls the following functions

1. windshield and tailgate wipers (5 door only)
2. windshield, rear windshield and headlamp washers
3. intermittent wiping
4. rain sensor.

The left-hand control stalk controls the following functions

1. turn signal lamps
2. high beam
3. headlamp flash
4. trip computer/timer start for the parking heater.

There are diagnostics for the functions of the steering wheel control stalks.

This function can be used to continuously read off the status of the control module's input and output signals.

For further information about parameters, see: DESCRIPTION OF PARAMETERS

New software can be downloaded into the steering wheel module (SWM). When ordering software, the hardware and the software in the car is compared to the information in the Volvo central database. If the comparison is OK the software is downloaded to the control module.

If the comparison between the car and Volvo central database is not OK, the database is updated with the car configuration. When this is complete the software is downloaded.

The control module is integrated in the steering wheel bracket. The steering wheel must be removed to replace the control module.

Scheme 165

The steering wheel angle sensor (7/91) is integrated in the Steering wheel module (SWM) (3/254) and registers information about the steering wheel's angle and the number of steering wheel turns that have been made. The Steering wheel module (SWM) then transmits the information via the CAN network to the Brake control module (BCM) (4/16) (only vehicles with DSTC) and the Electrical power steering module (EPS) (4/99).

CONTROLLING FUNCTIONS AND MENU SELECTION USING THE STEERING WHEEL BUTTONS

See

1. audio module (AUD)
2. multimedia module (MMM)
3. engine control module (ECM)
4. phone module (PHM)
5. infotainment control module (ICM).
6. Bluetooth phone module (BPM).

Scheme 166

The left-hand control stalk (3/133) is used to control the trip computer and to display and erase text messages in the driver information module (DIM) (5/1). The steering wheel module (SWM) (3/254) transmits information to the driver information module (DIM) (5/1) on the controller area network (CAN) indicating which function is selected.

The trip computer menu is controlled using the roller on the left-hand control stalk. Turn the roller forwards or backwards to scroll through the menu one step at a time. Some menu selections, such as average speed and fuel consumption, can be reset using the RESET button.

Error messages displayed in the driver information module (DIM) display are erased using the READ button.

The steering wheel module (SWM) has the task of managing the signals for the steering angle sensor and for those functions which can be controlled via the steering wheel control stalks and buttons.

The signals are transmitted to the relevant control modules via the control area network (CAN) or using LIN communication.

Steering wheel module (SWM) is available, from and incl. model year 2005 up to and incl. model year 2008, in two different versions. One version with more and one with less functionality.

Steering wheel module (SWM) with more functionality is installed in vehicles with Dynamic Stability and Traction system (DSTC). From and incl. model year 2009 there is only Steering wheel module (SWM) with more functionality.

The steering wheel module (SWM) manages signals for the following functions

1. steering wheel angle information (only vehicles equipped with DSTC)
2. steering wheel angle speed for electro-hydraulic power steering
3. volume control and CD track / radio selection
4. volume control for hands-free calls and menu selection for Phone module (PHM), which includes starting, ending and receiving calls
5. volume control for hands-free calls and menu selection for Bluetooth phone module (BPM), which includes starting, ending and receiving calls
6. menu selection for traffic information (RTI)
7. windshield washers and wipers
8. tailgate wiper and washer
9. headlamp washers
10. cruise control
11. turn signal lamps
12. high and low beam
13. trip computer and displaying/erasing text messages in the driver information module (DIM)
14. rain sensor module (RSM)
15. parking heater.

The control module is integrated in the steering wheel bracket. The steering wheel must be removed to replace the control module.

Control stalks, key pads and switches can be replaced as separate units.

The Steering wheel module (SWM) communicates with directly connected components (steering wheel buttons) via LIN communication.

The control module also communicates with other control modules via both CAN and LIN communication.

The control module checks activations and input and output signals via an integrated diagnostic system. A diagnostic trouble code (DTC) is stored if the control module detects a fault. For further information, see: DIAGNOSTIC TROUBLE CODES (DTCS)

The diagnostic trouble code (DTC) is stored when the ignition is switched off.

Any diagnostic trouble codes (DTCs) are stored in the control module memory. This information can be read off using VIDA (Volvo scan tool) via the data link connector (DLC) in the vehicle.

A simple way to ensure that the steering wheel module (SWM) is powered and grounded is to activate the turn signal lamps or to change the audio or carphone volume.

For further information, see SIGNALS .

The table below summarizes the input signals to and output signals from the steering wheel module (SWM). The signal types are divided into directly connected signals, LIN and CAN communication. The illustration below (Scheme 167) displays the same information with the Volvo component designations.

Scheme 167

Scheme 168

The Subwoofer module (SUB) contains an amplifier.

The amplifier has two channels, one for each sound axis. The output from each channel of the amplifier is 130 W at 4 ohms. Power booster amplification is set so that the acoustic output from the subwoofer module (SUB) matches the other speaker channels.

When transferring sound signals to the subwoofer module (SUB), the infotainment control module (ICM) allocates a channel on the MOST network. The audio module (AUD) transmits sound signals to the subwoofer module (SUB) via the MOST network. All filtering and sound treatment of the sound signal takes place in the audio module (AUD). Volume control takes place in the subwoofer module (SUB).

The volume of the subwoofer module (SUB) is raised or lowered using the volume knob on the infotainment control module (ICM). The infotainment control module (ICM) transmits a request on the MOST network to the subwoofer module (SUB), which then processes the request and actively raises or lowers the volume.

The limiter function in the subwoofer module (SUB) does not permit an increase in the output level if this would lead to a fall in sound quality.

The subwoofer module (SUB) is powered via the central electronic module (CEM).

Scheme 169

There are two subwoofers, these are located behind the rear seat backrests.

The speaker elements are two 9 inch subwoofers with a voice coil in each. The impedance is 4 ohms for each voice coil.

This function can be used to read parameters, status identifiers and counters stored at the same time as a diagnostic trouble code (DTC). These are called frozen values.

New software can be downloaded into the subwoofer module (SUB). When ordering software, the hardware and the software in the car is compared to the information in the Volvo central database. If the comparison is OK the software is downloaded to the control module.

If the comparison between the car and Volvo's central database does not correspond, then the database is updated with the vehicle's configuration. When this is complete the software is downloaded.

The subwoofer module (SUB) is on the left-hand side in the cargo compartment.

After replacing the subwoofer module (SUB), the unique serial numbers of the control module are checked by the infotainment control module (ICM). The installed subwoofer module (SUB) will not work if the serial number is incorrect.

If a problem arises after software download and the control module does not work, try switching the ignition off and on.

Select the MOST network for a total download of software to the vehicle.

SUBWOOFER MODULE (SUB)

See subwoofer module (SUB).

Scheme 170

The primary task of the subwoofer module (SUB) is to manage sound reproduction from the audio module (AUD) to the subwoofer.

The subwoofer module (SUB) only functions if the audio module (AUD) is connected to the MOST network.

The Subwoofer module (SUB) checks activations and input and output signals via an integrated diagnostic system. A diagnostic trouble code (DTC) is stored in certain cases if the control module detects a fault. Any diagnostic trouble codes (DTCs) are stored in the control module memory.

The subwoofer module (SUB) uses the MOST network to communicate with other control modules.

In order to work correctly on the MOST network, the infotainment control module (ICM) checks that the serial number in the Subwoofer module (SUB) is correct. The subwoofer module (SUB) will not function if the serial number is incorrect. Try switching the ignition off and on if there are problems when replacing the control module.

A simple way to check whether the subwoofer module (SUB) is functioning is to switch the radio on and then change the volume. The volume from the subwoofer module (SUB) should rise and fall with the changes.

Note. Ensure that the bass loudspeaker is selected in the infotainment control module (ICM).

The subwoofer module (SUB) is on the left-hand side in the cargo compartment.

For further information, see SIGNALS .

The table below summarizes the input signals to and output signals from the Subwoofer module (SUB). The signal types are divided into directly connected signals and MOST communication. The illustration below (Scheme 171) displays the same information with the Volvo component designations.

Scheme 171

Scheme 172

The Subwoofer module (SUB) contains an amplifier.

The amplifier has two channels, one for each voice coil. The output from each channel on the amplifier is 130 W at 4 ohms.

Power booster amplification is set so that the acoustic output from the subwoofer module (SUB) matches the other speaker channels.

Subwoofer module (SUB) is 30 supplied.

SUBWOOFER

There are two subwoofers, these are installed behind the backrests.

The speaker elements are two 9 inch subwoofers with a voice coil in each. The impedance is 4 ohms for each voice coil.

READING OFF THE PARAMETERS

This function is used to read the status or value of parameters. The status or value can be presented digitally.

ACTIVATING COMPONENTS/FUNCTIONS

This function can be used to activate components/functions which affect the Subwoofer module (SUB).

READING OFF STATIC DATA

This function allows programmed data to be read off or data such as customer parameters to be programmed in.

This function can be used to read out parameters, identify status and counts stored at the same time as a diagnostic trouble code (known as frozen values).

Scheme 173

During the transmission of sound signals to the Subwoofer module (SUB) (16/79), the Infotainment control module (ICM) (16/1.2) allocates a channel on the MOST network. The Audio module (AUD) (16/105) transmits sound signals to Subwoofer module (SUB) via the MOST network.

All filtering and sound treatment of the sound signal occurs in the Audio module (AUD).

Volume control occurs in the Subwoofer module (SUB).

The volume of the subwoofer module (SUB) is raised or lowered using the volume knob on the infotainment control module (ICM). The infotainment control module (ICM) transmits a request on the MOST network to the subwoofer module (SUB), which then processes the request and actively raises or lowers the volume.

The limiter function in the subwoofer module (SUB) does not permit an increase in the output level if this would lead to a reduction in sound quality.

SOFTWARE DOWNLOAD AND REPLACING THE CONTROL MODULE

New software can be downloaded into the subwoofer module (SUB). When ordering software, the hardware and the software in the car is compared to the information in the Volvo central database. If the comparison is OK the software is downloaded to the control module.

If the comparison between the car and Volvo's central database does not correspond, the database is updated with the vehicle's configuration. When this is complete, new software is downloaded.

The subwoofer module (SUB) is on the left-hand side in the cargo compartment.

Select download MOST network for a total download of software to the vehicle.

The primary task of the subwoofer module (SUB) is to manage sound reproduction from the audio module (AUD) to the subwoofers.

The subwoofer module (SUB) only functions if the audio module (AUD) is connected to the MOST network.

The Subwoofer module (SUB) checks activations and input and output signals via an integrated diagnostic system. A diagnostic trouble code (DTC) is stored in certain cases if the control module detects a fault. Any diagnostic trouble codes (DTCs) are stored in the control module memory.

The subwoofer module (SUB) uses the MOST network to communicate with other control modules.

In order to function in the MOST network, the Infotainment control module (ICM) checks that the correct serial number is in the Subwoofer module (SUB).

If the number is not correct, the Subwoofer module (SUB) will not function. If the problem persists when replacing the control module, try with the ignition on/off.

A simple way of checking if the Subwoofer module (SUB) functions is to activate the radio and then adjust the volume.

The sound from the Subwoofer module (SUB) should rise and fall as the control is adjusted.

Note. Make sure that the bass speaker is activated in the infotainment control module (ICM).

The subwoofer module (SUB) is on the left-hand side in the cargo compartment.

For further information, see SIGNALS .

The table below summarizes the input signals to and output signals from the Subwoofer module (SUB). The signal types are divided into directly connected signals and MOST communication. The illustration below (Scheme 174) displays the same information with the Volvo component designations.

Scheme 174

The Subwoofer module (SUB) contains an amplifier.

The amplifier has two channels, one for each voice coil. The output from each channel on the amplifier is 130 W at 4 ohms.

Power booster amplification is set so that the acoustic output from the subwoofer module (SUB) matches the other speaker channels.

Subwoofer module (SUB) is 30 supplied.

There are two subwoofers, these are installed behind the backrests.

The speaker elements are two 9 inch subwoofers with a voice coil in each.

The impedance is 4 ohms for each coil.

This function is used to read the status or value of parameters. The status or value can be presented digitally.

This function can be used to activate components/functions which affect the Subwoofer module (SUB).

This function allows programmed data to be read off or data such as customer parameters to be programmed in.

This function can be used to read out parameters, identify status and counts stored at the same time as a diagnostic trouble code (known as frozen values).

New software can be downloaded into the subwoofer module (SUB). When ordering software, the hardware and the software in the car is compared to the information in the Volvo central database. If the comparison is OK the software is downloaded to the control module.

If the comparison between the car and Volvo's central database does not correspond, the database is updated with the vehicle's configuration. When this is complete, new software is downloaded.

The subwoofer module (SUB) is on the left-hand side in the cargo compartment.

Select download MOST network for a total download of software to the vehicle.

Scheme 175

During the transfer of sound signals to the Subwoofer module (SUB) (16/79), the Infotainment control module (ICM) (3/281) allocates a channel on the MOST network. The Audio module (AUD) (16/105) transmits sound signals to Subwoofer module (SUB) via the MOST network.

All filtering and sound treatment of the sound signal occurs in the Audio module (AUD).

Volume control occurs in the Subwoofer module (SUB).

The volume of the subwoofer module (SUB) is raised or lowered using the volume knob on the infotainment control module (ICM). The infotainment control module (ICM) transmits a request on the MOST network to the subwoofer module (SUB), which then processes the request and actively raises or lowers the volume.

The limiter function in the subwoofer module (SUB) does not permit an increase in the output level if this would lead to a reduction in sound quality.

The primary task of the subwoofer module (SUB) is to manage sound reproduction from the audio module (AUD) to the subwoofers.

The subwoofer module (SUB) only functions if the audio module (AUD) is connected to the MOST network.

The Subwoofer module (SUB) checks activations and input and output signals via an integrated diagnostic system. A diagnostic trouble code (DTC) is stored in certain cases if the control module detects a fault. Any diagnostic trouble codes (DTCs) are stored in the control module memory.

The subwoofer module (SUB) uses the MOST network to communicate with other control modules.

In order to function in the MOST network, the Infotainment control module (ICM) checks that the correct serial number is in the Subwoofer module (SUB).

If the number is not correct, the Subwoofer module (SUB) will not function. If the problem persists when replacing the control module, try with the ignition on/off.

A simple way of checking if the Subwoofer module (SUB) functions is to activate the radio and then adjust the volume.

The sound from the Subwoofer module (SUB) should rise and fall as the control is adjusted.

Note. Ensure that the bass loudspeaker is selected in the infotainment control module (ICM).

The subwoofer module (SUB) is on the left-hand side in the cargo compartment.

For further information, see SIGNALS .

The table below summarizes the input signals to and output signals from the Subwoofer module (SUB). The signal types are divided into directly connected signals and MOST communication. The illustration below (Scheme 176) displays the same information with the Volvo component designations.

Scheme 176

Scheme 177

The primary task of the supplemental restraint system module (SRS) is to minimize injuries to the driver and passengers in different types of accident. To do this, the control module measures the acceleration signals generated by a collision and then determines the required action. The control module has internal and external sensors. Using the data collected from the sensors, the control module determines which of the following protection systems will be activated

1. seat belt tensioners front seat
2. front airbags
3. adaptive steering column.
4. adaptive seatbelt force limiter.
5. seat belt tensioners rear seat
6. side impact protection (SIPS) bags
7. door mounted inflatable curtains
8. ROPS (Roll Over Protection System).

The collision sensors in the control module and the frontal collision sensor and the side collision sensors register the mechanical stresses that occur in the event of a collision. The stresses are measured by the acceleration and pressure sensors. If the stresses exceed a certain level, the collision pulse starts to be calculated. The calculation evaluates whether the collision pulse was sufficient to activate the protection system. Airbags and seat belt tensioners can be activated individually.

Certain markets also use

1. an occupant weight sensor (OWS) located under the seat cushion on the front passenger seat
2. two seat position sensors located on the rail under the driver's seat and front passenger seat.

The driver and passenger airbags and the seat belt tensioners are designed to deploy in the event of a frontal collision as necessary. In USA/CDN, the adaptive steering column and the function for adaptive seatbelt force limiting are also activated as necessary.

In the event of a side impact, the side airbags and the door mounted inflatable curtain on the impact side activate, as well as the seat belt tensioners in the front seat.

In the event of a rear impact, the front seat belt tensioners and the ROPS (Roll Over Protection System) are activated as necessary.

The control module has a local CAN network connected to it (only applies to USA/CDN). The occupant weight sensor (OWS) is connected to the controller area network (CAN).

Note. The on/off switch for the front passenger airbag and occupant weight sensor (OWS) must not be installed in the vehicle together.

The control module has a collision recording function. This records certain system information in the event of a collision. If necessary, this information can be analyzed and used after a collision. This information is used to develop the collision safety systems of the future. The control module can store information from 3 collisions. If 3 collisions have occurred no more information can be stored and the control module must be replaced. A diagnostic trouble code (DTC) is stored when the control module has stored information from 3 collisions.

In the event of a frontal collision, side on collision, rear collision or a roll, a collision signal is transmitted from the supplemental restraint system module (SRS) to the phone module (PHM) and the central electronic module (CEM) using a directly connected cable. The purpose of this signal is to

1. switch off the fuel pump (FP)
2. switch off the engine cooling fan (FC)
3. switch off the windshield wipers when the car is stationary
4. switch on the interior lighting and the courtesy lighting
5. set the vehicle to collision status
6. unlock the central locking system and
7. if the vehicle is equipped with Volvo On Call (Plus), send an automatic alarm to CSC (Customer Service Center).

A collision signal is also sent to the phone module (PHM) and the central electronic module (CEM) via the Controller area network (CAN).

The supplemental restraint system module (SRS) decides to deploy the airbags and/or the seat belt tensioners and/or adaptive steering column and/or the function for adaptive seatbelt force limiting in the event of a frontal collision. This depends on whether

1. if the driver and front passenger are wearing seat belts or not
2. if there is a fault in the seat belt buckles
3. if there is a fault in the controller area network (CAN) communication.

As a result of the above conditions, in the event of a low impact collision the seat belt tensioner may deploy on the driver's side (belted driver) while the airbag is deployed on the passenger side (non belted passenger).

The SRS indicator lamp lights when the ignition is switched on. If no faults are registered by the control module, either internally or from the sensors, wiring or igniters, a signal is transmitted via the CAN network to the Driver information module (DIM) confirming that the SRS indicator lamp can be switched off. If there is a fault, the supplemental restraint system module (SRS) transmits information to the driver information module (DIM) indicating which lamp should be lit and the text to be displayed in the combined instrument panel

1. The SRS indicator lamp
2. the general warning lamp or
3. the yellow information lamp.

The driver information module (DIM) continuously transmits information to the supplemental restraint system (SRS) control module via the controller area network (CAN) about the status of the SRS indicator lamp.

If the SRS indicator lamp stops working, the general red warning lamp is used instead.

Note that after a collision, it may be necessary to replace the cable harness for the components of the protection system which have deployed. This is because the connectors may melt at the moment of deployment. If a connector has melted, the cable harness adjacent to the connector must be replaced.

Scheme 178

The side impact sensors in the vehicle are used to measure the mechanical stresses that occur in the event of a collision.

The four sensors which are used in the car are

1. 1 side impact sensor in each left and right B post
2. 1 side impact sensor in each left and right door.

The side impact sensors in the B-post are acceleration sensors while the side impact sensors in the doors are pressure sensors. The sensors transmit data continuously to the control module. In the event of a collision, the control module uses the acceleration and pressure data from the sensors, and the control module's internal sensors to determine if the collision severity is enough to activate the side impact protection system.

Only the side impact protection system on the collision side is activated.

In the event of a fault in the side impact sensor, the control module stores a diagnostic trouble code (DTC). A diagnostic trouble code (DTC) is also stored if the communication between the control module and one of the side impact sensors does not function. Each side impact sensor has a serial number. The serial number is used to check that the correct side impact sensor is installed.

If one (or several) of the side impact sensors stops functioning, the control module uses the remaining sensor to determine when the collision protection should be activated.

Note. The side impact sensors in the B-posts are the same and can be installed on the left or right side, but cannot be used in the doors. The side impact sensors in the doors are also the same and can be either installed in the left or right door.

Data is transmitted on the same cable used for power supply. There is a signal/power supply cable to each side impact sensor and a ground lead.

Scheme 179

The frontal impact sensors are used to provide the supplemental restraint system module (SRS) with advance information about the collision pulse. This enables the control module to determine the components to be activated more accurately.

The frontal impact sensors have integrated logic which transmits acceleration data to the supplemental restraint system module (SRS) in the same way as the side impact sensors.

In the event of a collision, the control module calculates the acceleration data from the frontal collision sensors and the internal sensors of the control module to check if the impact is sufficiently great to activate the frontal impact protection.

In the event of a fault in a frontal impact sensor, the control module stores a diagnostic trouble code (DTC). A diagnostic trouble code (DTC) is also stored if the communication between the control module and one of the frontal impact sensors does not function. Each frontal impact sensor has a serial number. The serial number is used to check that the correct frontal impact sensor is installed.

If one or both of the frontal impact sensors stops functioning, the control module uses the remaining acceleration sensor to determine when the collision protection should be activated.

Data is transmitted on the same cable used for power supply. There is a signal/power supply cable to each frontal impact sensor and a ground lead.

The two frontal impact sensors are behind the left and right-hand headlamps.

Scheme 180

The seat position sensor is used to determine the size of the person sitting on the seat. There are two seat position sensors in the vehicle, one under the driver's seat and one under the front passenger seat. The seat position sensors are directly connected to the supplemental restraint system module (SRS). The seat position sensors have separate signal cables to the control module and a common ground.

The seat position sensor consists of a Hall sensor which modifies the current depending on the position of the seat. The seat position sensor has two classifications, these are a small person and a large person. A small person means that the seat is approximately 10 cm from the first seat position and forwards. Other positions are classified as a large person.

This information is used by the function for adaptive seatbelt force limiting.

Scheme 181

The occupant weight sensor (OWS) consists of three interactive components

1. The pressure sensor, installed under the front passenger seat
2. The seatbelt force sensor, mounted in the seat frame on the outside of the front passenger seat
3. Occupant weight sensor module, installed under the front passenger seat.

The pressure sensor registers the pressure the seat is exposed to, for example when someone is sitting in the car. Information from the seat belt force sensor is also used to ensure the good performance of the system. The seatbelt force sensor informs the occupant weight sensor module what force the belt is tensioned with. This is done because the pressure measured by the pressure sensor can be affected by the passenger fastening the seatbelt over themselves or child seat tightly. This means that the passenger or child seat exerts greater pressure on the seat than during normal seatbelt use. The passenger or child seat is then interpreted as being heavier than he or she is. The occupant weight sensor module uses the information from both the pressure sensor and seatbelt force sensor to calculate the actual weight of the passenger. The occupant weight sensor (OWS) transmits continuous signals on the local controller area network (CAN) which the supplemental restraint system module (SRS) and occupant weight sensor (OWS) are connected to. If the occupant weight sensor (OWS) does not function correctly the supplemental restraint system module (SRS) will

1. deactivate the front passenger airbag
2. light the warning lamp for passenger airbag disconnected (PAD) in the roof console
3. light the SRS (supplemental restraint system) indicator lamp and display the alert message in the driver information module (DIM).

If a fault occurs in any of the components the following should be noted

1. The pressure sensor and occupant weight sensor module must be replaced at the same time
2. The seatbelt force sensor is replaced separately.

Note. The on/off switch for the front passenger airbag and occupant weight sensor (OWS) must not be installed in the vehicle together.

Scheme 182

The adaptive seatbelt force limiter improves the seatbelt function in the event of a frontal collision when the airbag has been activated. There are two adaptive seatbelt force limiters in the car. These are integrated in the seat belt reel, positioned at shoulder height on the driver's and front passenger seatbelts.

The adaptive seatbelt force limiters are electrically separated from each other. The adaptive seatbelt force limiters have a pyrotechnic charge which adapts the seatbelt force to a lower level against the chest on activation.

The adaptive seatbelt force limiter, seat belt reel, seat belt (inertia) reel sensor and seat belt tensioner are installed in a single unit. In the event of a fault in any of these the whole unit must be replaced.

Scheme 183

When the collision protection system in the collapsible steering column is activated, a pin deploys enabling the steering column to be adjusted for length. The steering wheel is pressed in further towards the dashboard than if the steering column was rigid.

The steering is not affected by the deployment of the pin. The pin is deployed by a pyrotechnical charge and is located in the center of the steering column. The collision protection system in the adaptive steering column only activates if the driver is wearing the seatbelt and if the airbag deploys. The entire steering column must be replaced if the collision protection system in the adaptive steering column has deployed.

Scheme 184

The airbags at the front of the vehicle are

1. driver airbag, 2 stage deployment
2. front passenger airbag, 2 stage deployment.

The driver's airbag is located in the steering wheel. The passenger airbag is located above the glove compartment in the dashboard.

The front airbags have two ignition components each. These are electrically separated from each other. This means that the different ignition components have their own separate power supply and grounding points from the control module. Two power supply outputs are required from the control module for each airbag, one for each ignition component. This means that in total four pins on the control module, two power supply pins and two ground pins, are used for each airbag.

When activating the airbags electrical signals are transmitted from the supplemental restraint system module (SRS) to the relevant airbag stage.

Stage 1

Stage 1 of the driver's airbag is pyrotechnic. In the event of activation the charge combusts and the gas which develops is blown into the airbag.

Stage 1 on the passenger airbag consists of a pyrotechnic component in combination with a reservoir which stores a gas. On activation the pyrotechnic charge combusts and mixes with the stored gas. The gas mixture inflates the airbag.

Stage 2

Stage 2 of the driver's and passenger airbags is pyrotechnical. In the event of activation the charge combusts and the gas which develops inflates the airbag.

The pace of the airbag 2 stage activation is dependent on the collision type and seat belt use. Both stages always activate. The difference is that in the event of a lesser impact, there is a greater time delay between stage 1 and stage 2. For more serious impacts the time delay is shorter between stages 1 and 2, which gives a stiffer airbag.

Scheme 185

There are two side impact protection (SIPS) bags connected to the supplemental restraint system module (SRS). Their connectors are electrically separated from each other. The side impact protection (SIPS) bags are on the outside of the backrest, underneath the upholstery, on the front seats. The side impact protection (SIPS) bags deploy on the side of the impact. Their task is to protect the hips, chest and upper body in the event of a side on collision.

The side airbags together with the door mounted inflatable curtains and other safety systems can help to protect the driver and front passenger in the event of a collision.

The side impact protection (SIPS) bag uses a pyrotechnic component in combination with a reservoir which stores a gas. On activation the pyrotechnic charge combusts and mixes with the stored gas. The gas mixture inflates the airbag.

Scheme 186

There are four seat belt tensioners in the vehicle. These are located at shoulder height, one for each seat belt reel, two at the front (1 and 2) and two in the rear seat (3 and 4).

Note. The seat belt tensioners for the USA/CDN market are marked " 1a " and " 2a " in the illustration. The seat belt tensioners for other markets (not USA/CDN) (1b and 2b) are marked " 1b " and " 2b " in the illustration.

The seat belt tensioner tensions the seat belt to reduce the forward movement of the body.

The supplemental restraint system module (SRS) determines whether to deploy the seat belt tensioners based on whether the seat belts are being used. The seat belt tensioner will not be activated if the seat belt is not engaged. If the seat belt is fastened and the seatbelt indication does not function for the front seat belt buckles, the seat belt tensioners will be activated anyway. Rear seat belt tensioner activation is market dependent.

The seat belt tensioner consists of a pyrotechnical charge and a cylinder with a piston. The piston is connected to a steel cable which is secured to the seat belt reel. When the control module activates the seat belt tensioner the piston is forced downwards by the expanding gas. The piston pulls in the steel cable which reels in the belt.

For USA/CDN: the adaptive seatbelt force limiter, seat belt reel, and seat belt tensioner are installed in a single unit. In the event of a fault in any of these the whole unit must be replaced.

Scheme 187

There are two inflatable curtains installed in the doors connected to the supplemental restraint system module (SRS). Their connectors are electrically separated from each other.

The door mounted inflatable curtains are positioned in the upper section of the left and right doors. They have only one ignition component each. The task of the door mounted inflatable curtains is to protect the head and the upper body in the event of a side impact. The Supplemental restraint system module (SRS) activates the door mounted inflatable curtains on the side of the impact.

The door mounted inflatable curtain uses a pyrotechnic component in combination with a reservoir which stores a gas. On activation the pyrotechnic charge combusts and mixes with the stored gas. The gas mixture is blown into the door mounted inflatable curtain, which inflates and covers the side windows.

Scheme 188

The retractable roof has a lower level of protection than a vehicle with a fixed roof. ROPS (Roll Over Protection System) is available to sufficiently protect the passengers in the event of the vehicle rolling over. The system consists of two roll-over bars and sensors in the Supplemental restraint system module (SRS).

The roll-over bars are integrated in a cassette and the entire roll-over bar cassette must be replaced if replacing the roll-over bars. Both roll-over bar cassettes are installed between the body plates behind the rear seat backrest. The roll-over bar cassettes are directly connected to the Supplemental restraint system module (SRS).

The sensors for roll-over are installed in the Supplemental restraint system module (SRS) and the entire control module must be replaced if replacing a sensor.

The system is normally inactive and is only activated when the vehicle rolls.

In this case, the roll-over bar cassettes and the seat belt tensioners and the door mounted inflatable curtains activate as well.

SRS INDICATION

The supplemental restraint system module (SRS) continuously checks the system. A diagnostic trouble code (DTC) is stored and an SRS indication is made.

SRS indication is accompanied by a text message in the Driver information module (DIM), partly through

1. an SRS warning lamp
2. a general warning lamp
3. a yellow information lamp.

The lamps light depending on how serious the fault is: Information about which lamp should be lit is transmitted by the supplemental restraint system module (SRS) on the controller area network (CAN).

The SRS indicator lamp lights when the ignition is switched on. If no faults are registered by the control module, either internally or from the sensors, wiring or igniters, a signal is transmitted on the controller area network (CAN) to the driver information module (DIM) confirming that the SRS indicator lamp can be switched off. If no faults are detected when the ignition is switched on, the lamp will remain lit for a few seconds. The lamp goes out when the system has been checked and is operating without faults.

The control module has an EEPROM memory which retains data about diagnostic trouble codes (DTCs) even when the battery has been disconnected.

The driver information module (DIM) continuously indicates to the supplemental restraint system module (SRS) the function of the SRS indicator lamp. If the lamp stops working, the general warning lamp lights up and a message is displayed.

Note. If a diagnostic trouble code (DTC) is stored because the resistance in an SRS ignition cable is too high or too low, it is important that the resistance of the SRS ignition cable is not measured when the collision protection system is connected. Special tools with the same resistance as the collision protection system must be used for fault-tracing.

Scheme 189

The supplemental restraint system module (SRS) transmits signals on the controller area network (CAN) to the central electronic module (CEM) indicating whether the front passenger airbag is activated or not. If the central electronic module (CEM) receives information that the passenger airbag is deactivated, it transmits a signal to the passenger airbag disconnected warning lamp (PAD). The signals are transmitted on a directly connected signal cable. The warning lamp which is in the roof console, lights and remains lit while the passenger seat airbag is disconnected.

Depending on the market, if the switch for activating and deactivating the front passenger airbag is used to deactivate it, the passenger airbag disconnected (PAD) warning lamp lights.

The warning lamp goes out when the airbag is reactivated.

If an occupant weight sensor (OWS) is installed (market dependent), the passenger airbag disconnected (PAD) warning lamp lights when the airbag is deactivated. However there is an exception to this

1. The passenger airbag disconnected warning lamp will remain unlit if the occupant weight sensor (OWS) registers that the passenger seat is unoccupied. This means that the passenger airbag is deactivated.

The warning lamp goes out when the airbag is reactivated.

Reasons that the passenger airbag disconnected warning lamp lights may also be

1. communication problems between the supplemental restraint system module (SRS) and central electronic module (CEM)
2. faulty function in the on/off switch for the front passenger airbag
3. defective occupant weight sensor (OWS) function.

Scheme 190

The two front seat belt buckles have Hall sensors and are connected to the SRS module. These connections are electrically separated from each other.

The Hall sensor detects whether the belt is engaged in the seat belt buckle or not and indicates this to the supplemental restraint system module (SRS). The information is used to set the activation level for airbags and seat belt tensioners. If a fault is detected in the seat belt buckles or in their terminals, an adjustment is made for this, depending on the type of fault.

The rear seat belt buckles can be connected (market dependent) to the central electronic module (CEM) which then transmits the status of the seat belt buckles to the SRS (supplemental restraint system) module via the controller area network (CAN). In the event of a fault in the rear seat belt buckles the seat belt tensioners will function as if the seatbelts are fastened (market dependent).

ACTIVATING AIRBAGS/SEAT BELT TENSIONERS

The collision safety system is extremely advanced. It is able to adapt airbag deployment and the activation of the seat belt tensioners to suit the specific circumstances of a collision. In general it is extremely unlikely that all airbags and seat belt tensioners will be deployed in the same accident. It is possible that only one airbag or seat belt tensioner is deployed. This is determined by the supplemental restraint system module (SRS) based on the forces that occur during the collision.

If the control module deploys the front airbags, both stages will always be activated. By varying the time between the two deployment phases, the inflation of the airbag is more gentle for a low speed collision.

DEPLOYMENT LEVELS FOR AIRBAGS/SEAT BELT TENSIONERS

The table below shows how the SRS system activates the protection system as necessary in the event of a frontal impact.

Level 1= Low speed collision

Level 5 = Severe collision

ACTIVATING THE SIDE IMPACT PROTECTION SYSTEM

The table below shows how the SRS system activates the protection system as necessary in the event of a side impact.

ACTIVATING THE COLLISION PROTECTION SYSTEM

The table below shows how the SRS system activates the protection system as necessary in the event of a rear impact.

Scheme 191

The on-board diagnostic (OBD) system for the supplemental restraint system module (SRS) continually diagnoses the function of supplemental restraint system components and stores any diagnostic trouble codes (DTCs). The diagnostic trouble codes (DTCs) can then be read off. Information is presented in the same way as with other diagnostic systems.

FAULT INDICATION

If a fault occurs in the SRS system the driver is warned in various ways via the combined instrument panel

1. the SRS indicator lamp lights up and text appears in the display
2. the general warning lamp lights and text appears in the display
3. the yellow information lamp lights and text appears in the display.

The diagnostic tool must be connected to the data link connector (DLC) in order to identify the source of the fault.

Data can be read off from the supplemental restraint system module (SRS) using this function.

New software for the supplemental restraint system module (SRS) can be downloaded. When ordering software, the hardware and the software in the car is compared to the information in the Volvo central database. If the comparison is OK, the software is downloaded to the control module.

If the comparison between the vehicle and Volvo central database is not OK, software downloading cannot occur.

When the control module is replaced, the new control module will have certain pre-programmed software.

The software which is pre-programmed is

1. application software
2. diagnostic software
3. collision algorithm software.

The software which will be downloaded is parameter files containing

1. parameters unique to this model
2. equipment for the vehicle (passenger air bag, adaptive seatbelt force limiter etc.)
3. a signal configuration file.

Scheme 192

When the ignition key is turned from 0 to I, II or III, the communication on the controller area network (CAN), the status of the internal functions in the supplemental restraint system module (SRS) (4/9) as well as all directly connected components are checked

1. airbags driver (8/30 and 8/61)
2. airbags passenger (8/31 and 8/32)
3. seat belt tensioners (8/33, 8/34, 8/55 and 8/56)
4. side impact sensors (7/115, 7/116, 7/208 and 7/209)
5. door mounted inflatable curtains (8/66 and 8/67)
6. SIPS bags (8/51 and 8/52)
7. frontal impact sensor (7/178 and 7/179)
8. front seat belt buckles (3/93 and 3/94)
9. adaptive steering column (8/99) (USA/CDN only)
10. seat position sensors (3/255 and 3/256) (USA/CDN only)
11. adaptive seatbelt force limiter (8/128 and 8/129) (USA/CDN only)
12. switch on/off, front passenger airbag (3/157) (not USA/CDN)
13. occupant weight sensor (OWS) (7/93) (USA/CDN only)
14. roll-over bar cassette (8/57 and 8/58).

The supplemental restraint system module (SRS) transmits information via the controller area network (CAN) to the driver information module (DIM) (5/1) indicating that this test is in progress. The central electronic module (CEM) (4/56) also transmits the parameter values during the status check.

The driver information module (DIM) then lights the SRS indicator lamp. The SRS indicator lamp is lit while the supplemental restraint system (SRS) is being checked. When the supplemental restraint system (SRS) has been tested and no faults have been detected, the SRS indicator lamp goes out.

If a fault is detected during the check it will be indicated in one of the following ways, depending on how serious it is

1. the SRS indicator lamp continues to light and a warning text is displayed in the driver information module (DIM)
2. the general red warning lamp lights and a warning text is displayed in the driver information module (DIM).
3. the general yellow warning lamp lights and a warning text is displayed in the driver information module (DIM).

The driver information module (DIM) continuously transmits a signal to the supplemental restraint system module (SRS) via the controller area network (CAN) with information about whether the SRS indicator lamp is working or not. The red general warning lamp lights up if the SRS indicator lamp stops working. If the CAN communication between the supplemental restraint system (SRS) module and the driver information module (DIM) fails, the SRS warning lamp lights up and text is displayed in the driver information module (DIM). If the faults disappear and the driver information module (DIM) can transmit information to the supplemental restraint system module (SRS) and the status of the SRS warning lamp is OK, the warning lamps will return to normal function.

Scheme 193

In the event of a side-on collision, the sensors in the Supplemental restraint system module (SRS) (4/9) and the side impact sensors (7/115, 7/116, 7/208 and 7/209) evaluate the force of the mechanical stresses. The Supplemental restraint system module (SRS) determines which protection system is to be activated in the situation.

If the impact fulfils the conditions to activate the side airbags (8/51 and 8/52) and the door mounted inflatable curtains (8/66 and 8/67) and/or seat belt tensioners front (8/33 and 8/34), the control module sends a current pulse to those protection systems that are to be deployed. The side impact protection system will only be deployed on the side where the impact is registered.

The control module also transmits a collision signal on a directly connected cable to the central electronic module (CEM) (4/56) and the phone module (PHM) (16/60), so that these control modules can take certain actions.

A collision status signal is also sent to the phone module (PHM) and the central electronic module (CEM) via the controller area network (CAN).

Scheme 194

In the event of a frontal collision, the sensors in the Supplemental restraint system module (SRS) (4/9) and frontal impact sensors (7/178 and 7/179) evaluate the mechanical stresses. The Supplemental restraint system module (SRS) determines which protection system is to be activated in the situation.

If the impact fulfils the conditions to activate the protection system the Supplemental restraint system module (SRS) sends an activation signal, a current pulse, to

1. front airbags (8/30, 8/31, 8/32 and 8/61) and/or
2. seat belt tensioner (8/33, 8/34, 8/55 and 8/56) and/or
3. the adaptive steering column (8/99) and/or
4. the function for adaptive seatbelt force limiting.

The passenger airbag will not be deployed if it is deactivated using the Occupant weight sensor (OWS) (7/93).

A collision signal is transmitted on a direct connection from the supplemental restraint system module (SRS) to the central electronic module (CEM) (4/56) and phone module (PHM) (16/60) when the collision protection system is activated. These two control modules ensure that

1. switch off the fuel pump (FP)
2. switch off the engine cooling fan (FC)
3. switch off the windshield wipers when the car is stationary
4. switch on the interior lighting and the courtesy lighting
5. set the vehicle to collision status
6. unlock the central locking system and
7. if the vehicle is equipped with Volvo On Call (Plus), send an automatic alarm to CSC (Customer Service Center).

Scheme 195

In the event of a roll over, the sensors, mounted in the Supplemental restraint system module (SRS) (4/9), evaluate the angle of the vehicle and how quickly the vehicle angle will change. When the movement has exceeded the predetermined limit, the following components are activated

1. door mounted inflatable curtains (8/66 and 8/67)
2. seat belt tensioners (8/33, 8/34, 8/55 and 8/56)
3. roll-over bar cassettes (8/57 and 8/58).

A collision signal is transmitted on a direct connection from the supplemental restraint system module (SRS) to the central electronic module (CEM) (4/56) and phone module (PHM) (16/60) when the collision protection system is activated. These two control modules ensure that

1. switch off the fuel pump (FP)
2. switch off the engine cooling fan (FC)
3. switch off the windshield wipers when the car is stationary
4. switch on the interior lighting and the courtesy lighting
5. set the vehicle to collision status
6. unlock the central locking system and
7. if the vehicle is equipped with Volvo On Call (Plus), send an automatic alarm to CSC (Customer Service Center).

Scheme 196

In the event of a frontal collision where the front airbags and the front seat belt tensioners have deployed (8/33 and 8/34), the function for adaptive seatbelt force limiting may be activated. The supplemental restraint system module (SRS) also receives information from the seat position sensor (3/255, 3/256) about the positions of the passenger or driver's seats. The control module can determine whether the occupant is a large or small person. Using this information, the supplemental restraint system module (SRS) determines whether the adaptive seatbelt force limiter should be activated. If the adaptive seatbelt force limiter (8/128, 8/129) is activated, the supplemental restraint system module (SRS) transmits an activation signal, current pulse, to the adaptive seatbelt force limiter which reduces the force of the seatbelt on the chest.

Scheme 197

Under normal conditions the information from the occupant weight sensor (OWS) system (7/93) is the basis for whether the supplemental restraint system module (SRS) (4/9) should activate or deactivate the front passenger airbag (8/31 and 8/32). The occupant weight sensor (OWS) communicates continuously with the supplemental restraint system (SRS) module via the local controller area network (CAN). When a passenger weighing more than a certain weight is in the seat, the supplemental restraint system module (SRS) is informed by the occupant weight sensor (OWS). The control module software activates the front passenger airbag, which means that the airbag has full functionality in the event of a collision. At the same time the supplemental restraint system module (SRS) transmits a signal on the controller area network (CAN), to the central electronic module (CEM) (4/56), with a request to switch off the passenger airbag disconnected warning lamp. The central electronic module (CEM) then switches off the passenger airbag disconnected (PAD) warning lamp.

If the weight on the front passenger seat is below a certain level the supplemental restraint system module (SRS) is informed by the occupant weight sensor (OWS). The control module software deactivates the front passenger airbag, which means that the airbag has no functionality in the event of a collision. At the same time the supplemental restraint system module (SRS) transmits a signal on the controller area network (CAN), to the central electronic module (CEM), with a request to switch on the passenger airbag warning lamp (passenger airbag disconnected). The central electronic module (CEM) then switches on the passenger airbag warning lamp (passenger airbag disconnected). However there is an exception to this

1. The passenger airbag disconnected warning lamp will remain unlit if the occupant weight sensor (OWS) registers that the passenger seat is unoccupied. This means that the passenger airbag is deactivated.

Note. The on/off switch for the front passenger airbag and occupant weight sensor (OWS) must not be installed in the vehicle together.

THE OCCUPANT WEIGHT SENSOR (OWS) SYSTEM (ONLY USA/CDN)

The occupant weight sensor (OWS) is designed to meet the regulatory requirements of Federal Motor Vehicle Safety Standard (FMVSS) 208 and is designed to disable (will not inflate) the passenger's side front airbag under certain conditions.

The occupant weight sensor (OWS) works with sensors that are part of the front passenger's seat and safety belt. The sensors are designed to detect the presence of a properly seated occupant and determine if the passenger's side front airbag should be enabled (may inflate) or disabled (will not inflate).

The occupant weight sensor (OWS) will disable (will not inflate) the passenger's side front airbag when

1. the front passenger seat is unoccupied, or there are small/medium objects in the front passenger seat
2. the system determines that an infant is present in a rear-facing infant seat that is installed according to the manufacturer's instructions
3. the system determines that a small child is present in a forward-facing child restraint that is installed according to the manufacturer's instructions
4. the system determines that a small child is present in a booster seat
5. a front passenger takes his/her weight off of the seat for a period of time
6. a child or a small person occupies the front passenger seat.

The occupant weight sensor (OWS) uses a passenger airbag warning lamp (PAD) which will illuminate and stay lit to remind you that the passenger's side front airbag is disabled. The passenger airbag warning lamp (PAD) is located in the overhead console.

Note. The passenger airbag warning lamp (PAD) will illuminate for a short period of time when the ignition is turned on to confirm it is functional.

When the front passenger seat is not occupied (empty seat) or in the event that the passenger's side front airbag is enabled (may inflate), the passenger airbag warning lamp (PAD) will be unlit.

The occupant weight sensor (OWS) is designed to disable (will not inflate) the passenger's side front airbag when a rear facing infant seat, a forward-facing child restraint, or a booster seat is detected. The passenger airbag warning lamp (PAD) will illuminate and stay lit to remind you that the passenger's side front airbag is disabled.

Note. Volvo recommends that children always be properly restrained in appropriate child restraints in the rear seats.

In rare situations when the safety belt is not latched, some child restraints may not be detected by the OWS because there is very little weight on the vehicle seat cushion. In these cases the passenger's side front airbag may be disabled, but the passenger airbag warning lamp (PAD) will not be lit. Do not assume that the passenger's side front airbag is disabled unless the passenger airbag warning lamp (PAD) is lit.

The occupant weight sensor (OWS) is designed to enable (may inflate) the passenger's side front airbag anytime the system senses that a person of adult size is sitting properly in the front passenger seat. The passenger airbag warning lamp (PAD) will be unlit and stay unlit.

The occupant weight sensor (OWS) detects pressure on the front passenger seat cushion as a result of load put in the seat. The occupant weight sensor (OWS) classifies the occupant as small or large based on whether the induced pressure is below or above a predetermined threshold. The threshold is defined between the pressure induced by children and the pressure induced by adults in accordance with the regulatory requirements of Federal Motor Vehicle Safety Standard (FMVSS) 208. If the occupant weight sensor (OWS) determines a small occupant classification, the passenger's side front airbag will be disabled and the passenger airbag warning lamp (PAD) will be lit. If The occupant weight sensor (OWS) determines a large occupant classification, the passenger's side front airbag will be enabled and the passenger airbag warning lamp (PAD) will be unlit.

The supplemental restraint system module (SRS) handles functions for

1. seat belt tensioners
2. side impact sensors
3. frontal impact sensor
4. seat position sensors
5. adaptive seatbelt force limiter
6. side impact protection (SIPS) bags
7. front airbags
8. door mounted inflatable curtains
9. SRS indication
10. passenger airbag indication
11. collision output signal
12. collision registration
13. adaptive steering column.
14. front seat belt buckles
15. local CAN network, Supplemental restraint system module (SRS)
16. occupant weight sensor (OWS).
17. ROPS (Roll Over Protection System).

The control module is in the transmission tunnel, between the gear selector lever and the parking brake.

The supplemental restraint system module (SRS) communicates with directly connected wiring and with other control modules via the controller area network (CAN). Depending on the market, the control module can also communicate with components via a local CAN network.

The control module checks the input and output signals through an integrated diagnostic system. A diagnostic trouble code (DTC) is stored if the control module detects a fault.

Any diagnostic trouble codes (DTCs) are stored in the control module memory. The information can be read out.

The control module can process multiple collisions, frontal collisions, collisions from behind, side-on collisions and overturning.

The control module function can be easily checked by switching on the ignition. The SRS indicator lamp in the combined instrument panel must light up when the key is in ignition positions I-III. The lamp goes out after a short while if no faults are detected. This means that the supplemental restraint system (SRS) is functioning correctly.

For further information, see SIGNALS .

The table below summarizes the input signals to and output signals from the supplemental restraint system module (SRS). The signal types are divided into directly connected signals and CAN communication. The illustration below (Scheme 198) displays the same information with the Volvo component designations.

Scheme 198

The primary task of the supplemental restraint system module (SRS) is to minimize injuries to the driver and passengers in different types of accident. To do this, the control module measures the acceleration signals generated by a collision and then determines the required action. The control module has internal and external sensors. Using the data collected from the sensors, the control module determines which of the following protection systems will be activated

1. seat belt tensioners front seat
2. front airbags
3. adaptive steering column (USA/CDN only)
4. adaptive seatbelt force limiter (USA/CDN only)
5. seat belt tensioners rear seat
6. side impact protection (SIPS) bags
7. door mounted inflatable curtains
8. ROPS (Roll Over Protection System).

The collision sensors in the control module and the frontal collision sensor and the side collision sensors register the mechanical stresses that occur in the event of a collision. The stresses are measured by the acceleration and pressure sensors. If the stresses exceed a certain level, the collision pulse starts to be calculated. The calculation evaluates whether the collision pulse was sufficient to activate the protection system. Airbags and seat belt tensioners can be activated individually.

Certain markets also use

1. an occupant weight sensor (OWS) located under the seat cushion on the front passenger seat
2. two seat position sensors located on the rail under the driver's seat and front passenger seat.

The driver and passenger airbags and the seat belt tensioners are designed to deploy in the event of a frontal collision as necessary. In USA/CDN, the adaptive steering column and the function for adaptive seatbelt force limiting are also activated as necessary.

In the event of a side impact, the side airbags and the door mounted inflatable curtain on the impact side activate, as well as the seat belt tensioners in the front seat.

In the event of a rear impact, the front seat belt tensioners and the ROPS (Roll Over Protection System) are activated as necessary.

The control module has a local CAN network connected to it (only applies to USA/CDN). The occupant weight sensor (OWS) is connected to the controller area network (CAN). There is also a switch on the passenger side of the dashboard. This switch can be used to activate or deactivate the passenger airbag using the ignition key (does not apply to USA/CDN).

Note. The activating switch, on/off, for the front passenger airbag and occupant weight sensor (OWS) must not be installed in the vehicle together.

The control module also has an accident data recorder that records certain system information in the event of a collision. This information can be analyzed and used after a collision as necessary and is used to develop the supplemental restraint systems of the future. The control module can store information from 3 collisions. Once 3 collisions have occurred, no more information can be stored and the control module must be replaced. A diagnostic trouble code is generated when the control module has stored information from 3 collisions.

In the event of a frontal collision, side on collision, rear collision or a roll, a collision signal is transmitted from the supplemental restraint system module (SRS) to the phone module (PHM) and the central electronic module (CEM) using a directly connected cable. The purpose of this signal is to

1. switch off the fuel pump (FP)
2. switch off the engine cooling fan (FC)
3. switch off the windshield wipers when the car is stationary
4. switch on the interior lighting and the courtesy lighting
5. set the vehicle to collision status
6. unlock the central locking system and
7. if the vehicle is equipped with Volvo On Call (Plus), send an automatic alarm to CSC (Customer Service Center).

A collision signal is also sent to the phone module (PHM) and the central electronic module (CEM) via the Controller area network (CAN).

The supplemental restraint system module (SRS) decides to deploy the airbags and/or the seat belt tensioners and/or adaptive steering column and/or the function for adaptive seatbelt force limiting in the event of a frontal collision. This depends on whether

1. if the driver and front passenger are wearing seat belts or not
2. if there is a fault in the seat belt buckles
3. if there is a fault in the controller area network (CAN) communication.

As a result of the above conditions, in the event of a low impact collision the seat belt tensioner may deploy on the driver's side (belted driver) while the airbag is deployed on the passenger side (non belted passenger).

The SRS indicator lamp lights when the ignition is switched on. If no faults are registered by the control module, either internally or from the sensors, wiring or igniters, a signal is transmitted via the CAN network to the Driver information module (DIM) confirming that the SRS indicator lamp can be switched off. If there is a fault, the supplemental restraint system module (SRS) transmits information to the driver information module (DIM) indicating which lamp should be lit and the text to be displayed in the combined instrument panel

1. The SRS warning lamp
2. the general warning lamp or
3. the yellow information light

The driver information module (DIM) continuously transmits information to the supplemental restraint system (SRS) control module via the controller area network (CAN) about the status of the SRS warning lamp.

If the SRS indicator lamp stops working, the general red warning lamp is used instead.

Note that after a collision, it may be necessary to replace the cable harness for the components of the protection system which have deployed. This is because the connectors may melt at the moment of deployment. If a connector has melted, the cable harness adjacent to the connector must be replaced.

SIDE IMPACT SENSOR

The side impact sensors in the vehicle are used to measure the mechanical stresses that occur in the event of a collision.

The four sensors which are used in the car are

1. 1 side impact sensor in each left and right B post
2. 1 side impact sensor in each left and right door.

The side impact sensors in the B-post are acceleration sensors while the side impact sensors in the doors are pressure sensors. The sensors transmit data continuously to the control module. In the event of a collision, the control module uses the acceleration and pressure data from the sensors, and the control module's internal sensors to determine if the collision severity is enough to activate the side impact protection system.

Only the side impact protection system on the collision side is activated.

In the event of a fault in the side impact sensor, the control module stores a diagnostic trouble code (DTC). A diagnostic trouble code (DTC) is also stored if the communication between the control module and one of the side impact sensors does not function. Each side impact sensor has a serial number. The serial number is used to check that the correct side impact sensor is installed.

If one (or several) of the side impact sensors stops functioning, the control module uses the remaining sensor to determine when the collision protection should be activated.

Note. The side impact sensors in the B-posts are the same and can be installed on the left or right side, but cannot be used in the doors. The side impact sensors in the doors are also the same and can be either installed in the left or right door.

Data is transmitted on the same cable used for power supply. There is a signal/power supply cable to each side impact sensor and a ground cable.

FRONT IMPACT SENSOR

The front impact sensors are used to provide the supplemental restraint system module (SRS) with advance information about the collision pulse. This enables the control module to more accurately determine which components to deploy.

The front impact sensors have integrated logic which transmits acceleration data to the supplemental restraint system module (SRS) in the same way as the side impact sensors.

In the event of a collision, the control module calculates the acceleration data from the frontal collision sensors and the internal sensors of the control module to check if the impact is sufficiently great to activate the frontal impact protection.

In the event of a fault in a frontal impact sensor, the control module stores a diagnostic trouble code (DTC). A diagnostic trouble code (DTC) is also stored if the communication between the control module and one of the frontal impact sensors does not function. Each frontal impact sensor has a serial number. The serial number is used to check that the correct frontal impact sensor is installed.

If one or both of the frontal impact sensors stops functioning, the control module uses the remaining acceleration sensor to determine when the collision protection should be activated.

Data is transmitted on the same cable used for power supply. There is a signal/power supply cable to each front impact sensor and a ground cable.

The two front impact sensors are behind the left and right-hand headlamps.

SEAT POSITION SENSORS

The seat position sensor is used to determine the size of the person sitting on the seat. There are two seat position sensors in the vehicle, one under the driver's seat and one under the front passenger seat. The seat position sensors are directly connected to the supplemental restraint system module (SRS). The seat position sensors have separate signal cables to the control module and a common ground.

The seat position sensor consists of a Hall sensor which modifies the current depending on the position of the seat. The seat position sensor has two classifications, these are a small person and a large person. A small person means that the seat is approximately 10 cm from the first seat position and forwards. Other positions are classified as a large person.

This information is used by the function for adaptive seatbelt force limiting.

OCCUPANT WEIGHT SENSOR (OWS)

The occupant weight sensor (OWS) consists of three interactive components

1. The pressure sensor, installed under the front passenger seat.
2. Belt force sensor, mounted in the seat frame on the outside of the front passenger seat.
3. Occupant weight sensor module, installed under the front passenger seat.

The pressure sensor and occupant weight sensor are linked via a hose. The pressure sensor registers the pressure the seat cushion is exposed to, for example when someone is sitting in the seat.

Information from the seat belt force sensor is also used to ensure the good performance of the system. The seatbelt force sensor informs the occupant weight sensor module what force the belt is tensioned with. This is done because the pressure measured by the pressure sensor can be affected by the passenger fastening the seatbelt tightly. This means that the passenger exerts greater pressure on the seat than during normal seatbelt use. The passenger is then interpreted as being heavier than he or she is.

Using information from both the pressure sensor and the seat belt force sensor, the occupant weight sensor module carries out calculations and classifications of what is affecting the system. This forms the basis for the recommendation that is communicated to the supplemental restraint system.

The occupant weight sensor (OWS) transmits continuous signals on the local controller area network (CAN), which the supplemental restraint system module (SRS) and occupant weight sensor (OWS) are connected to. If the occupant weight sensor (OWS) does not function correctly the supplemental restraint system module (SRS) will

1. disable the front passenger airbag
2. light the passenger airbag warning lamp (PAD) in the roof console
3. light the SRS (supplemental restraint system) warning lamp and display the alert message in the driver information module (DIM).

If a fault occurs in any of the components the following should be noted

1. The pressure sensor and occupant weight sensor module must be replaced at the same time
2. The seat belt force sensor is replaced separately.

Note. The activating switch, on/off, for the front passenger airbag and occupant weight sensor (OWS) must not be installed in the vehicle together.

ADAPTIVE SEATBELT FORCE LIMITER

The adaptive seatbelt force limiter improves the seatbelt function in the event of a frontal collision when the airbag has been activated. There are two adaptive seatbelt force limiters in the car. These are integrated in the seat belt reel, positioned at shoulder height on the driver's and front passenger seatbelts.

The adaptive seatbelt force limiters are electrically separated from each other. The adaptive seatbelt force limiters have a pyrotechnic charge which adapts the seatbelt force to a lower level against the chest on activation.

The adaptive seatbelt force limiter, seat belt reel, seat belt (inertia) reel sensor and seat belt tensioner are installed in a single unit. In the event of a fault in any of these the whole unit must be replaced.

ADAPTIVE STEERING COLUMN

When the collision protection system in the collapsible steering column is activated, a pin deploys enabling the steering column to be adjusted for length. The steering wheel is pressed in further towards the dashboard than if the steering column was rigid.

Steering is not affected by the deployment of the pin. The pin is deployed by a pyrotechnical charge and is located in the center of the steering column. The impact protection system in the adaptive steering column only deploys if the driver is wearing the seat belt and when the airbag is deployed. The entire steering column must be replaced if the impact protection system in the adaptive steering column has deployed.

FRONT AIRBAGS

The airbags at the front of the vehicle are

1. driver airbag, 2 stage deployment
2. front passenger airbag, 2 stage deployment.

The driver's airbag is located in the steering wheel. The passenger airbag is located above the glove compartment in the dashboard.

The front airbags have two ignition components each. These are electrically separated from each other. This means that the different ignition components have their own separate power supply and grounding points from the control module. Two power supply outputs are required from the control module for each airbag, one for each ignition component. This means that in total four pins on the control module, two power supply pins and two ground pins, are used for each airbag.

During airbag deployment, electrical signals are transmitted from the supplemental restraint system module (SRS) to the relevant airbag stage.

Stage 1

Stage 1 of the driver's airbag is pyrotechnic. In the event of activation the charge combusts and the gas which develops is blown into the airbag.

Stage 1 on the passenger airbag consists of a pyrotechnic component in combination with a reservoir which stores a gas. In the event of deployment, the pyrotechnic charge combusts and mixes with the stored gas. The gas mixture inflates the airbag.

Stage 2

Stage 2 of the driver's and passenger airbags is pyrotechnical. In the event of activation the charge combusts and the gas which develops inflates the airbag.

The pace of the airbag 2 stage activation is dependent on the collision type and seat belt use. Both stages always activate. The difference is that in the event of a lesser impact, there is a greater time delay between stage 1 and stage 2. For more serious impacts the time delay is shorter between stages 1 and 2, which gives a stiffer airbag.

SIDE IMPACT AIR BAGS

There are two side impact protection (SIPS) bags connected to the supplemental restraint system module (SRS). Their connectors are electrically separated from each other. The side impact protection (SIPS) bags are on the outside of the backrest, underneath the upholstery, on the front seats. The side impact protection (SIPS) bags deploy on the side of the impact. Their task is to protect the hips, chest and upper body in the event of a side on collision.

The side airbags together with the door mounted inflatable curtains and other safety systems can help to protect the driver and front passenger in the event of a collision.

The side airbag uses a pyrotechnic component in combination with a reservoir which stores a gas. In the event of deployment, the pyrotechnic charge combusts and mixes with the stored gas. The gas mixture inflates the airbag.

BELT TENSIONERS

There are four seat belt tensioners in the vehicle. These are located at shoulder height, one for each seat belt reel, two at the front (1 and 2) and two in the rear seat (3 and 4).

Note. USA/CDN have seatbelt tensioners (1a and 2a) as shown above. Other markets (not USA/CDN) have seatbelt tensioners (1b and 2b) as shown above.

The seat belt tensioner tensions the seat belt to reduce the forward movement of the body.

The supplemental restraint system module (SRS) determines whether to deploy the seat belt tensioners based on whether the seat belts are being used. The seat belt tensioner will not be activated if the seat belt is not engaged. If the seat belt is fastened and the seatbelt indication does not function for the front seat belt buckles, the seat belt tensioners will be activated anyway. Rear seat belt tensioner activation is market dependent.

The belt tensioner consists of a pyrotechnical charge and a cylinder with a piston. The piston is connected to a steel cable which is secured to the seat belt retractor. When the control module deploys the belt tensioner, the piston is forced downward by the expanding gas. The piston pulls in the steel cable which retracts the belt.

For USA/CDN: the adaptive seatbelt force limiter, seat belt reel, and seat belt tensioner are installed in a single unit. In the event of a fault in any of these the whole unit must be replaced.

DOOR MOUNTED INFLATABLE CURTAINS

There are two inflatable curtains installed in the doors connected to the supplemental restraint system module (SRS). Their connectors are electrically separated from each other.

The door mounted inflatable curtains are positioned in the upper section of the left and right doors. They have only one ignition component each. The task of the door mounted inflatable curtains is to protect the head and the upper body in the event of a side impact. The Supplemental restraint system module (SRS) activates the door mounted inflatable curtains on the side of the impact.

The door mounted inflatable curtain uses a pyrotechnic component in combination with a reservoir which stores a gas. On activation the pyrotechnic charge combusts and mixes with the stored gas. The gas mixture is blown into the door mounted inflatable curtain, which inflates and covers the side windows.

ROPS (ROLL OVER PROTECTION SYSTEM)

The retractable roof has a lower level of protection than a vehicle with a fixed roof. ROPS (Roll Over Protection System) is available to sufficiently protect the passengers in the event of the vehicle rolling over. The system consists of two roll-over bars and sensors in the Supplemental restraint system module (SRS).

The roll-over bars are integrated in a cassette and the entire roll-over bar cassette must be replaced if replacing the roll-over bars. Both roll-over bar cassettes are installed between the body plates behind the rear seat backrest. The roll-over bar cassettes are directly connected to the Supplemental restraint system module (SRS).

The sensors for roll-over are installed in the Supplemental restraint system module (SRS) and the entire control module must be replaced if replacing a sensor.

The system is normally inactive and is only activated when the vehicle rolls.

In this case, the roll-over bar cassettes and the seat belt tensioners and the door mounted inflatable curtains activate as well.

The supplemental restraint system module (SRS) continuously checks the system. A diagnostic trouble code (DTC) is stored and an SRS indication is made.

SRS indication is accompanied by a text message in the Driver information module (DIM), partly through

1. an SRS warning lamp
2. a general warning lamp
3. a yellow information lamp.

The lamps light depending on how serious the fault is: Information about which lamp should be lit is transmitted by the supplemental restraint system module (SRS) on the controller area network (CAN).

The SRS warning lamp lights when the ignition is switched on. If no faults are registered by the control module, either internally or from the sensors, wiring or igniters, a signal is transmitted on the controller area network (CAN) to the driver information module (DIM) confirming that the SRS warning lamp can be switched off. If no faults are detected when the ignition is switched on, the lamp will remain lit for a few seconds. The lamp goes out when the system has been checked and is operating without faults.

The control module has an EEPROM memory which retains data about diagnostic trouble codes (DTCs) even when the battery has been disconnected.

The driver information module (DIM) continuously indicates to the supplemental restraint system module (SRS) the function of the SRS warning lamp. If the lamp stops working, the general warning lamp lights up and a message is displayed.

Note. If a diagnostic trouble code is stored because the resistance in an ignition cable is too high or too low, it is important that the resistance of the ignition cable is not measured when the collision protection system is connected. Special tools with the same resistance as the collision protection system must be used for troubleshooting.

Scheme 199

Supplemental restraint system module (SRS) sends signals on the CAN-net to Central electronic module (CEM) about the airbag for passenger front is activated or not.

If Central electronic module (CEM) receives information that passenger airbag is activated, it sends signals on a directly connected cable to light warning light activated airbag passenger (PAE) (1).

It works in the same way if Central electronic module (CEM) receives information that the passenger airbag is deactivated, but then the signal to light the warning light airbag passenger (PAD) (2) is sent.

The lights are located in the overhead panel. Each light is on until Central electronic module (CEM) receives information that status of the passenger airbag has been changed.

Depending on the market, if the switch for activating and deactivating the front passenger airbag is used to deactivate it, the passenger airbag disconnected (PAD) warning lamp lights.

The warning light goes off when the airbag is activated again and then warning light activated passenger (PAE) is lit instead.

If an occupant weight sensor (OWS) is installed (market-dependent), the passenger airbag warning light (PAD) lights when the airbag is deactivated.

The warning lamp goes out when the airbag is enabled.

If Occupant weight sensor (OWS) is installed, there is no warning light activated airbag passenger (PAE) installed.

Reason the passenger airbag warning lamp (PAD) lights could also be

1. communication problems between the supplemental restraint system module (SRS) and central electronic module (CEM)
2. faulty function in the on/off switch for the front passenger airbag
3. defective occupant weight sensor (OWS) function.

SEATBELT BUCKLE

The two front seat belt buckles have Hall sensors and are connected to the SRS module. These connections are electrically separated from each other.

The Hall sensor detects whether the belt is engaged in the seat belt buckle or not and indicates this to the supplemental restraint system module (SRS). The information is used to set the activation level for airbags and seat belt tensioners. If a fault is detected in the seat belt buckles or in their terminals, an adjustment is made for this, depending on the type of fault.

The rear seat belt buckles can be connected (market dependent) to the central electronic module (CEM) which then transmits the status of the seat belt buckles to the SRS (supplemental restraint system) module via the controller area network (CAN). In the event of a fault in the rear seat belt buckles the seat belt tensioners will function as if the seatbelts are fastened (market dependent).

The collision safety system is extremely advanced. It is able to adapt airbag deployment and the activation of the seat belt tensioners to suit the specific circumstances of a collision. In general it is extremely unlikely that all airbags and seat belt tensioners will be deployed in the same accident. It is possible that only one airbag or seat belt tensioner is deployed. This is determined by the supplemental restraint system module (SRS) based on the forces that occur during the collision.

If the control module deploys the front airbags, both stages will always be activated. By varying the time between the two deployment phases, the inflation of the airbag is more gentle for a low speed collision.

The table below shows how the SRS system activates the protection system as necessary in the event of a frontal impact.

Level 1= Low speed collision

Level 5 = Severe collision

DEPLOYING THE SIDE IMPACT PROTECTION SYSTEM

The table below shows how the SRS system activates the protection system as necessary in the event of a side impact.

The table below shows how the SRS system activates the protection system as necessary in the event of a rear impact.

If a fault occurs in the SRS system the driver is warned in various ways via the combined instrument panel

1. the SRS indicator lamp lights up and text appears in the display
2. the general warning lamp lights and text appears in the display
3. the yellow information lamp lights and text appears in the display.

The diagnostic tool must be connected to the data link connector (DLC) in order to identify the source of the fault.

Data can be read off from the supplemental restraint system module (SRS) using this function.

New software for the supplemental restraint system module (SRS) can be downloaded. When ordering software, the hardware and the software in the car is compared to the information in the Volvo central database. If the comparison is OK, the software is downloaded to the control module.

If the comparison between the vehicle and Volvo central database is not OK, software downloading cannot occur.

When the control module is replaced, the new control module will have certain pre-programmed software.

The software which is pre-programmed is

1. application software
2. diagnostic software
3. collision algorithm software.

The software which will be downloaded is parameter files containing

1. parameters unique to this model
2. equipment for the vehicle (passenger air bag, adaptive belt force limiter etc.)
3. a signal configuration file.

CHECKING THE SRS SYSTEM

When the ignition key is turned from 0 to I, II or III, the communication on the controller area network (CAN), the status of the internal functions in the supplemental restraint system module (SRS) (4/9) as well as all directly connected components are checked

1. airbags driver (8/30 and 8/61)
2. airbags passenger (8/31 and 8/32)
3. seat belt tensioners (8/33, 8/34, 8/55 and 8/56)
4. side impact sensors (7/115, 7/116, 7/208 and 7/209)
5. door mounted inflatable curtains (8/66 and 8/67)
6. SIPS bags (8/51 and 8/52)
7. front impact sensor (7/178 and 7/179)
8. front seat belt buckles (3/93 and 3/94)
9. adaptive steering column (8/99) (only USA/CDN)
10. seat position sensor (3/255 and 3/256) (only USA/CDN)
11. adaptive seat belt force limiter (8/128 and 8/129) (only USA/CDN)
12. switch on/off, front passenger airbag (3/157) (not USA/CDN)
13. occupant weight sensor (OWS) (7/93) (only USA/CDN)
14. roll-over bar cassette (8/57 and 8/58).

The supplemental restraint system module (SRS) transmits information via the controller area network (CAN) to the driver information module (DIM) (5/1) indicating that this test is in progress. The central electronic module (CEM) (4/56) also transmits the parameter values during the status check.

The driver information module (DIM) then lights the SRS warning lamp. The SRS warning lamp is lit while the supplemental restraint system (SRS) is being checked. When the supplemental restraint system (SRS) has been tested and no faults have been detected, the SRS warning lamp goes out.

If a fault is detected during the check it will be indicated in one of the following ways, depending on how serious it is

1. the SRS indicator lamp continues to light and a warning text is displayed in the driver information module (DIM).
2. the general red warning light lights and a warning text is displayed in the driver information module (DIM).
3. the general yellow warning lamp lights and a warning text is displayed in the driver information module (DIM).

The driver information module (DIM) continuously transmits a signal to the supplemental restraint system module (SRS) via the controller area network (CAN) with information about whether the SRS warning lamp is working or not. The red general warning lamp lights up if the SRS warning lamp stops working. If the CAN communication between the supplemental restraint system (SRS) module and the driver information module (DIM) fails, the SRS warning lamp lights up and text is displayed in the driver information module (DIM). If the faults disappear and the driver information module (DIM) can transmit information to the supplemental restraint system module (SRS) and the status of the SRS warning lamp is OK, the warning lamps will return to normal function.

SIDE IMPACT

In the event of a side-on collision, the sensors in the Supplemental restraint system module (SRS) (4/9) and the side impact sensors (7/115, 7/116, 7/208 and 7/209) evaluate the force of the mechanical stresses. The Supplemental restraint system module (SRS) determines which protection system is to be activated in the situation.

If the impact fulfils the conditions to activate the side airbags (8/51 and 8/52) and the door mounted inflatable curtains (8/66 and 8/67) and/or seat belt tensioners front (8/33 and 8/34), the control module sends a current pulse to those protection systems that are to be deployed. The side impact protection system will only be deployed on the side where the impact is registered.

The control module also transmits a collision signal on a directly connected cable to the central electronic module (CEM) (4/56) and the phone module (PHM) (16/60), so that these control modules can take certain actions.

A collision status signal is also sent to the phone module (PHM) and the central electronic module (CEM) via the controller area network (CAN).

FRONT-END COLLISION

In the event of a frontal collision, the sensors in the Supplemental restraint system module (SRS) (4/9) and frontal impact sensors (7/178 and 7/179) evaluate the mechanical stresses. The Supplemental restraint system module (SRS) determines which protection system is to be activated in the situation.

If the impact fulfils the conditions to activate the protection system the Supplemental restraint system module (SRS) sends an activation signal, a current pulse, to

1. front airbags (8/30, 8/31, 8/32 and 8/61) and/or
2. seat belt tensioner (8/33, 8/34, 8/55 and 8/56) and/or
3. the adaptive steering column (8/99) and/or
4. the function for adaptive seatbelt force limiting.

The passenger airbag will not be deployed if it is deactivated using the Occupant weight sensor (OWS) (7/93).

A collision signal is transmitted on a direct connection from the supplemental restraint system module (SRS) to the central electronic module (CEM) (4/56) and phone module (PHM) (16/60) when the collision protection system is activated. These two control modules ensure that

1. switch off the fuel pump (FP)
2. switch off the engine cooling fan (FC)
3. switch off the windshield wipers when the car is stationary
4. switch on the interior lighting and the courtesy lighting
5. set the vehicle to collision status
6. unlock the central locking system and
7. if the vehicle is equipped with Volvo On Call (Plus), send an automatic alarm to CSC (Customer Service Center).

ROLL OVER

In the event of a roll over, the sensors, mounted in the Supplemental restraint system module (SRS) (4/9), evaluate the angle of the vehicle and how quickly the vehicle angle will change. When the movement has exceeded the predetermined limit, the following components are activated

1. door mounted inflatable curtains (8/66 and 8/67)
2. seat belt tensioners (8/33, 8/34, 8/55 and 8/56)
3. roll-over bar cassettes (8/57 and 8/58).

A collision signal is transmitted on a direct connection from the supplemental restraint system module (SRS) to the central electronic module (CEM) (4/56) and phone module (PHM) (16/60) when the collision protection system is activated. These two control modules ensure that

1. switch off the fuel pump (FP)
2. switch off the engine cooling fan (FC)
3. switch off the windshield wipers when the car is stationary
4. switch on the interior lighting and the courtesy lighting
5. set the vehicle to collision status
6. unlock the central locking system and
7. if the vehicle is equipped with Volvo On Call (Plus), send an automatic alarm to CSC (Customer Service Center).

FUNCTION FOR ADAPTIVE SEAT BELT FORCE LIMITATION

In the event of a frontal collision where the front airbags and the front seat belt tensioners have deployed (8/33 and 8/34), the function for adaptive seatbelt force limiting may be activated. The supplemental restraint system module (SRS) also receives information from the seat position sensor (3/255, 3/256) about the positions of the passenger or driver's seats. The control module can determine whether the occupant is a large or small person. Using this information, the supplemental restraint system module (SRS) determines whether the adaptive seatbelt force limiter should be activated. If the adaptive seatbelt force limiter (8/128, 8/129) is activated, the supplemental restraint system module (SRS) transmits an activation signal, current pulse, to the adaptive seatbelt force limiter which reduces the force of the seatbelt on the chest.

ACTIVATING/DEACTIVATING FRONT PASSENGER AIRBAG

In normal conditions it is the information from the Occupant weight sensor (OWS) (7/93) that is the basis for if the Supplemental restraint system module (SRS) (4/9) shall activate or deactivate the front passenger airbag (8/31 and 8/32). Occupant weight sensor (OWS) communicates continuously with Supplemental restraint system module (SRS) on the local CAN-network. When a passenger is seated, with a weight exceeding a certain level, in the passenger seat the Occupant weight sensor (OWS) will inform the Supplemental restraint system module (SRS) about this. Then the control module's software activates the front passenger airbag, which means that the airbag has full function in case of a collision. At the same time, the Supplemental restraint system module (SRS) sends a signal on the CAN-network, to the central electronic module (CEM) (4/56), with a request that the warning light passenger airbag (PAD) shall be turned off. Then the Central electronic module (CEM) turns off the warning light for passenger airbag (PAD).

If the weight in the passenger seat front is under a certain level, then the Occupant weight sensor (OWS) will inform Supplemental restraint system module (SRS) about this. The control module's software then deactivates airbag passenger front, which means that the airbag remains inactive in case of a collision. At the same time the Supplemental restraint system module (SRS) sends a signal on the CAN-net, to Central electronic module (CEM), with a request to turn on warning light airbag passenger (PAD). Then Central electronic module (CEM) turns on warning light airbag passenger (PAD).

Note. The activating switch, on/off, for the front passenger airbag and occupant weight sensor (OWS) must not be installed in the vehicle together.

THE OCCUPANT WEIGHT SENSOR (OWS) SYSTEM

The occupant weight sensor (OWS) is designed to meet the regulatory requirements of Federal Motor Vehicle Safety Standard (FMVSS) 208 and is designed to disable (will not inflate) the passenger's side front airbag under certain conditions.

The occupant weight sensor (OWS) works with sensors that are part of the front passenger's seat and safety belt. The sensors are designed to detect the presence of a properly seated occupant and determine if the passenger's side front airbag should be enabled (may inflate) or disabled (will not inflate).

The occupant weight sensor (OWS) will disable (will not inflate) the passenger's side front airbag when

1. the front passenger seat is unoccupied, or there are small/medium objects in the front passenger seat
2. the system determines that an infant is present in a rear-facing infant seat that is installed according to the manufacturer's instructions
3. the system determines that a small child is present in a forward-facing child restraint that is installed according to the manufacturer's instructions
4. the system determines that a small child is present in a booster seat
5. a front passenger takes his/her weight off of the seat for a period of time
6. a child or a small person occupies the front passenger seat.

The occupant weight sensor (OWS) uses a passenger airbag warning lamp (PAD) which will illuminate and stay lit to remind you that the passenger's side front airbag is disabled. The passenger airbag warning lamp (PAD) is located in the overhead console.

Note. The passenger airbag warning lamp (PAD) will illuminate for a short period of time when the ignition is turned on to confirm it is functional.

In cases when the airbag on the passenger side front (inflation possible) is activated, then warning light airbag passenger (PAD) will not be on.

The occupant weight sensor (OWS) is designed to disable (will not inflate) the passenger's side front airbag when a rear facing infant seat, a forward-facing child restraint, or a booster seat is detected. The passenger airbag warning lamp (PAD) will illuminate and stay lit to remind you that the passenger's side front airbag is disabled.

Note. Volvo recommends that children always be properly restrained in appropriate child restraints in the rear seats.

The occupant weight sensor (OWS) is designed to enable (may inflate) the passenger's side front airbag anytime the system senses that a person of adult size is sitting properly in the front passenger seat. The passenger airbag warning lamp (PAD) will be unlit and stay unlit.

The occupant weight sensor (OWS) detects pressure on the front passenger seat cushion as a result of load put in the seat. The occupant weight sensor (OWS) classifies the occupant as small or large based on whether the induced pressure is below or above a predetermined threshold. The threshold is defined between the pressure induced by children and the pressure induced by adults in accordance with the regulatory requirements of Federal Motor Vehicle Safety Standard (FMVSS) 208. If the occupant weight sensor (OWS) determines a small occupant classification, the passenger's side front airbag will be disabled and the passenger airbag warning lamp (PAD) will be lit. If the occupant weight sensor (OWS) determines a large occupant classification, the passenger's side front airbag will be enabled and the passenger airbag warning lamp (PAD) will be unlit.

The supplemental restraint system module (SRS) handles functions for

1. seat belt tensioners
2. side impact sensors
3. frontal collision sensors
4. seat position sensors (USA/CDN only)
5. adaptive seatbelt force limiter (USA/CDN only)
6. side impact protection (SIPS) bags
7. front airbags
8. door mounted inflatable curtains
9. SRS indication
10. passenger airbag indication
11. collision output signal
12. collision registration
13. adaptive steering column (USA/CDN only)
14. front seat belt buckles
15. local CAN network, supplemental restraint system module (SRS)
16. occupant weight sensor (OWS) (USA/CDN only)
17. switch on/off, front passenger airbag (not USA/CDN)
18. ROPS (Roll Over Protection System).

The control module is in the transmission tunnel, between the gear selector lever and the parking brake.

The supplemental restraint system module (SRS) communicates with directly connected components and with other control modules via the controller area network (CAN). Depending on the market, the control module can also communicate with components via a local CAN network.

The control module checks the input and output signals through an integrated diagnostic system. A diagnostic trouble code (DTC) is stored if the control module detects a fault.

Any diagnostic trouble codes (DTCs) are stored in the control module memory. The information can be read out.

The control module can process multiple collisions, frontal collisions, collisions from behind, side-on collisions and overturning.

The control module function can be easily checked by switching on the ignition. The SRS indicator lamp in the combined instrument panel must light up when the key is in ignition positions I-III. The lamp goes out after a short while if no faults are detected. This means that the supplemental restraint system (SRS) is functioning correctly.

For further information, see SIGNALS .

The table below summarizes the input signals to and output signals from the supplemental restraint system module (SRS). The signal types are divided into directly connected signals and CAN communication. The illustration below see scheme 143 displays the same information with the Volvo component designations.

Scheme 200

1. Upper bearing, upper mount and spring seat
2. Rear bushing
3. Clamp
4. Anti-roll bar
5. Spring
6. Lower seat
7. Wheel spindle
8. Sub-frame
9. Front bushing
10. Control arm
11. Ball joint
12. Spring strut.

The front suspension is of the McPherson type, which means that the wheels are independently sprung.

The suspension on either side consists of: sprint strut (12), control arm (10) and wheel spindle (7). The anti-roll bar (4) is secured in the sub-frame (8) with two clamps (3) and in the spring strut (12). There are a number of anti-roll bar variants.

Spring strut

The upper end of the spring strut is anchored to the wheel arch by way of the upper bearing and the upper mounting (1). The lower end of the spring strut (12) is attached to the wheel spindle (7). The spring strut consists of a pipe into the lower part of which the wheel spindle is pressed and bolted. The wheel spindle is attached to the control arm via the ball joint (11). The ball joint is secured in the lower part of the wheel spindle. The lower spring seat (6) welded to the upper part of the tube.

Shock absorber

The shock absorber is integrated in the spring strut.

The shock absorber is located in the pipe and is held in place by a screw in the upper end and a seat in the bottom of the pipe.

The shock absorber piston rod is guided by the upper bearing (1). The upper bearing is secured in the upper mount. The bearing consists of a bearing pressed into a plate sleeve which is vulcanized with rubber. Against the upper bearing, the spring provides support via the upper spring seat (1). On the underside of the spring seat there is a buffer and a protective sleeve for the shock absorber piston.

Control arm

The control arm (10) is mounted on the sub-frame (8) using the front bushing (9) and the rear bushing (2).

The Toe-in/Toe-out is adjusted using the tie rods.

Sub-frame

The sub-frame (8) is made of two welded plates and a number of smaller plates.

The rear bushing (2) is bolted to the sub-frame.

Settings

There are two different settings for shock absorber, spring and anti-roll bar: dynamic setting or comfort setting.

Axle shaft

The drive shaft joint is secured with a locking bolt.

STEERING

See: STEERING

Scheme 201

1. Lower control arm
2. Sub-frame
3. Anti-roll bar
4. Wheel sensor
5. Upper control arm
6. Tie rod
7. Lateral link.

Upper control arm

The upper control arm (5) is cast.

Tie rod

The tie rod (6) is produced as a single steel stamp.

Lower control arm

The lower control arm (1) is steel stamped. It is installed between the lateral link (7) and the sub-frame (2).

The Toe-in/Toe-out can be adjusted using the inner mounting on the control arm. The anti-roll bar (3) is mounted in the lower control arm. There are two different mounting variants.

Anti-roll bar

There are a number of anti-roll bar variants (3).

Sub-frame

The sub-frame (2) is made of metal.

Wheel sensor

The wheel sensors (4) are located on the rear wheel bearings. They measure the speed of the vehicle using magnetic discs.

Scheme 202

1. Steering column
2. Steering shaft
3. Inner seal
4. Outer seal
5. Tie rod
6. Steering gear
7. Servo pump
8. Filling container for servo oil
9. Heat shield
10. Pump motor
11. Electrical power steering module (EPS).

Mechanical

Mechanical steering wheel movements are transferred to the wheels via the steering column (1), steering shaft (2), steering gear (6) and tie rods (5). The wheel deflection is limited by a stop in the steering gear.

Hydraulics

The steering system is electro-hydraulic and is servo operated. The electric power steering module (EPS) (11), pump motor (10), oil reservoir (8) and servo pump (7) constitute a single unit.

The steering gear is of the rack and pinion type and grease lubricated.

It is installed with two screws in the sub-frame.

The total oil volume in the steering system is 1.2 liters.

The oil level is checked with the aid of the filling container (8).

The outer seal (4) is secured with catches in the steering gear pinion housing. The inner seal (3) is secured with plastic mounting elements against the cowl panel from inside the passenger compartment. The seals prevent sound from the engine compartment being transferred into the passenger compartment. They also seal against water, dirt and fire.

The heat shield (9) is secured to the steering gear housing using three screws. It protects the steering gear from heat radiation from the three-way catalytic converter (TWC), exhaust pipe and turbocharger (TC).

Scheme 203

The adaptive steering column is a complete unit. It contains the following components

1. Fixed bracket
2. Running bracket
3. Upper steering section
4. Adjuster lever
5. Lock mechanism
6. Upper joint
7. Lower joint
8. Steering shaft.

The fixed bracket (1) is mounted in a bracket on the pipe arm and the cowl panel.

The steering column is adjustable for both height and reach.

It has an electrical steering lock with a mechanical locking function.

The steering shaft is divided into two parts and has two joints. A joint between the upper and lower steering shaft sections and a joint as the connection to the steering gear.

Scheme 204

1. Input shaft
2. Torsion bar
3. Dust boot
4. Seal
5. Rotary valve
6. Seal
7. Journal bearing
8. Gear drive
9. Actuating piston
10. Bearing
11. Steering gear housing
12. Rack
13. Cylinder pipe
14. Tie rod
15. Protecting bellow
16. Seal
17. Internal pipe.

This description refers to the steering gear.

The steering gear is of the rack and pinion type with the mechanical and servo assisted elements combined in one module.

The mechanical element consists of the gear drive (8), steering rack (12) and tie rods (14).

The gear drive is carried by a journal bearing (7) and a roller bearing (10) in the steering gear housing.

The steering rack is carried by a journal bearing on the right end and in the housing is guided by the gear drive (8) and the sprung actuating piston (9).

A cylinder pipe (13) is secured to the steering gear housing (11). This pipe functions as the power steering working cylinder for the hydraulic piston fastened to the steering rack.

The oil flow to the hydraulic cylinder is regulated in the valve housing which is integrated into the steering gear housing.

Valve assembly

The gear drive is driven by the steering gear input shaft (1) which has exterior lugs. There is radial play between the lugs.

A torsion bar (2) which joins the input shaft to the gear drive holds the lugs in a position where the play is equal on each side when there is no steering input on the shaft.

The torsion bar is pressed into the gear drive. The gear drive is fastened to the input shaft with a pressed in lock pin.

A rotary valve (5) is located in the valve assembly and fixed to the gear drive with a lock pin. The valve operating range is radial between four narrow vertical channels in the rotary valve and four milled grooves in the input shaft.

The valve is balanced as a complete unit and cannot be rebalanced.

Scheme 205

1. Electrical power steering module (EPS)
2. Oil reservoir and servo pump
3. Pump motor and sealed control module
4. Filling container for servo oil
5. Steering gear.

The electric power steering module (EPS) (1), pump motor (3), oil reservoir and servo pump (2) constitute a replaceable unit.

The electrical connections for the control module are located on the top of the control module.

The servo pump contains a gear pump and a pump motor. The pump is located in the oil reservoir (2). The pump motor (3) is located under the oil reservoir. The pump motor is a DC motor containing no brushes. The pump motor has four rotary windings. The control module is sealed in the pump motor.

Scheme 206

1. Fixed bracket
2. Running bracket
3. Upper steering section
4. Adjuster lever
5. Steering shaft
6. Tear plate
7. Pin (only USA/CDN)
8. Explosive charge (only USA/CDN)
9. Steering lock.

Deformation in the event of a collision

An impact of approximately 2 kN is required for the steering column to start to deform. Deformation takes place in three stages

1. The upper steering section (3) is pushed into the running bracket (2) equivalent to the remaining potential adjustment in the adjustment mechanism (4)
2. The tear plate (6) is deformed. The running bracket (2) is pushed into the fixed bracket (1). The groove for the running bracket controls the length of deformation
3. The steering shaft (5) with its telescopic design slides together.

The maximum movement (deformation) of the steering column is approximately 95 mm.

Collision process (only USA/CDN)

Driver not wearing seat belt

The pin (7) engages. This results in the tear plate using its entire structure to absorb energy. The deformation takes place stiffly and slowly.

Driver wearing seat belt

The explosive charge (8) is activated and pushes down the pin (7) out of the tear plate (6). The tear plate is weakened and the kinetic energy of the collision is transferred on in the system. This produces a relatively soft deformation process.

The collision protection system only works if the driver is wearing a seat belt and the airbag deploys.

Collision process (not USA/CDN)

The steering column does not have an explosive charge. The pin (7) is therefore always engaged. This means that the tear plate (6) uses its entire structure to absorb energy, irrespective of whether or not the driver is wearing a seat belt. The deformation takes place stiffly and slowly.

Electrical steering lock with mechanical locking function

The steering lock (9) is secured in the steering column with two security bolts.

The mechanical locking function for the locking mechanism consists of

1. a lug on the steering wheel lock
2. a pipe and catch on the steering column
3. a pin for locking the lug.

The lug is pushed into the tube with the catch, locking the steering wheel. In the event of damage to the steering lock cover, the pin blocks the lug in the locked position.

Scheme 207

1. Neutral
2. Steering left
3. Steering right
4. Servo oil, free flow
5. Servo oil, high pressure
6. Servo oil, low pressure
7. Air.

The steering gear power steering function is schematically displayed in (Scheme 207) and under STEERING, VALVE SECTION.

The force of oil pressure built up in the power steering pump affects the piston on the steering rack. The oil flow to the right or left-hand side of the piston is regulated in the valve housing. External pipes lead to both sides from the valve housing. The power steering pump pressure hose is connected to the valve housing.

The valve spool has three radial grooves, a small one that is fed by the power steering pump and an upper and a lower groove that are connected with the working cylinders via the outer pipe.

Scheme 208

Neutral

1. To the right-hand side of the piston

2. To the left-hand side of the piston

3. Outward

4. Fluid return

5. Servo oil, free flow

The valve is open when the vehicle's engine is running and there is no steering input. In the open position, none of the ducts to the operating cylinders are blocked. The servo oil circulates freely through the valve.

Scheme 209

Steering left

6. Servo oil, low pressure

7. Servo oil, high pressure

When the steering wheel is turned to the left and the wheel resistance is so great that the torsion bar inertia is overcome, the steering gear input shaft moves to the left in relation to the worm screw, within the play between the lugs.

With this movement the input shaft stops the free flow through the valve and sends the fluid through the upper feed pipe to the right-hand side of the piston.

As long as the torsion bar is affected by steering input, the oil pressure continues to push the steering rack to the left and servo assistance is obtained. If the steering input reduces, the torsion bar springs back. The valve section then reverts to the center position so that the oil can circulate freely through the valve housing.

Scheme 210

Steering right

6. Servo oil, low pressure

7. Servo oil, high pressure

The function when turning right is, in principle, the same as to the left. The only difference is that the steering gear input shaft stops the flow of high pressure oil through the return and down through the groove on the inside of the valve and out through the low pressure pipe to the left-hand side of the piston.

STEERING, ELECTRICAL POWER STEERING MODULE (EPS)

The power steering system employs the electro-hydraulic principle and is controlled by the electric power steering module (EPS).

Its task is to regulate the power steering affect for the vehicle optimally, using relevant input signals, and always to provide optimum servo assistance, regardless of whether the vehicle is stationary with the engine running or being driven at high speed.

The pump is a gear type pump.

The pump motor is controlled by the electric power steering module (EPS). The pump motor has Hall sensors, which inform the electric power steering module (EPS) about the present pump motor speed. At the same time, information is provided about the relevant hydraulic pressure, which is indirectly dependent on the speed.

Scheme 211

Front wheel suspension

The front suspension is of the McPherson type.

Rear suspension

The rear suspension comprises a "Multi link rear axle".

Steering

The electrical power steering pump consists of

1. servo pump
2. pump motor
3. electrical power steering module (EPS).

Servo assistance is determined by the steering gear torsion valve together with the electrical power steering module (EPS).

The torsion valve determines

1. if servo assistance is required
2. in which direction servo assistance should go
3. how much of the available pump assistance should be used.

The electrical power steering module (EPS) determines the RPM of the pump using

1. the vehicle speed
2. the steering wheel angle sensor.

The electric motor provides the pump with the power required to supply the correct hydraulic flow and pressure to the steering gear.

The adaptive steering column allows a relatively gentle deformation process in the event of a collision (only applies to drivers wearing seat belts, USA/CDN).

Steering shaft

The steering shaft is divided into two parts. The upper part of the steering column is further divided to prevent intrusion into the passenger compartment in event of a collision.

CAN NETWORK

CAN (control area network) is a standardized system for multiplex-communication. Multiplex communication means that several control modules can use the same cables for communication without traffic from one control module interfering with traffic from another.

Volvo has developed a new standard for multiplex communication - VOLCANO. VOLCANO is a development of CAN and uses real time operation and prioritization. The description of prioritization is based on VOLCANO but is designated CAN.

The control area network (CAN) standard specifies

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

Scheme 212

The CAN H and CAN L cables must not be confused with HS CAN and LS CAN which are speeds on the control 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.

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.

When measuring between CAN L and ground, the average voltage level during normal use is about 1.8-2.2 V.

When measuring between CAN H and ground, the average voltage level during normal use is about 2.8-3.2 V.

The difference in voltages is due to vehicle configuration and equipment level. Thus, voltages may differ between vehicles of the same model.

When measuring between the two CAN-cables, at normal traffic on the network, the average voltage level is approx. 0.55-0.90 V (up to max. 0.6-1.4 V)

Volvo's CAN-net meets ISO 11898-2. Other standard is 11898-3 where the voltage on CAN H changes from approx. 5 V to approx. 1 V, and CAN L from approx. 0 V to approx. 4 V when changing from logic "0" to logic "1". Other standard is SAE J2411 where only one cable is used for CAN-communication.

Scheme 213

The message consists of the following components

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

A complete CAN-message is called a frame.

PRIORITIZATION

Conflicts can arise in a network when several control modules try to transmit messages at the same time. For example, if the driver brakes at the same time as the front seat passenger changes the climate control settings and a passenger in the rear seat uses the power windows.

To ensure safe operation the messages must be prioritized. In addition, the delays that arise when messages are queued must be reasonable. This is so the customer does not feel the system is slow.

To resolve conflicts and delays messages are prioritized ensuring functionality.

The prioritization of messages is determined by the number of zeroes at the beginning of a message. The more zeroes the higher the priority.

Prioritization occurs as follows

1. When the network is available all the control modules with "something to say" send bit one in their message
2. All the control modules detect what has been transmitted on the network
3. If a control module has transmitted 0 those that have sent 1 stop and wait until the next time the network is available
4. Those that transmitted 0 transmit bit two of the message
5. If a control module has transmitted 0 as bit two those that have sent 1 stop and wait until the next time the network is available and so on.

The message with the highest priority (most zeroes at the beginning) "wins" and is sent first.

The end of a message is seven zeroes. The control modules then know that the network is available and a new message can be sent in priority order.

TWO TYPES OF MESSAGE

There are two types of message in the system

1. Periodical frames. These messages are sent regularly and give the present status of a parameter. They are used for information which is frequently updated, speed signals for example
2. Event frames, which are only sent when predetermined conditions have been met. This type of message is used for things that seldom occur, raising / lowering a window for example.

The message can contain an update bit which states how "fresh" the information is.

The system assumes that the receiver has received the message so an acknowledgment is not sent. A reply is only sent to a direct question from another control module.

But the receiver "knows" how often it should receive a message about the status that applies. If the message is missing the receiver can connect an emergency program and / or set a diagnostic trouble code.

QUALITY FACTOR

In a distributed system where information (signals) is sent between different control modules in a network, it is usually the control module that generates/creates information (the signal) that knows the quality of the information that is sent. To be able to inform receiving control modules about the quality of information, a quality factor (Q-factor) is sent over the network at the same time as the information (signal). The quality factor describes status of the information. For example, if the signal is defective due to a faulty sensor, a receiving control module can use the quality factor to decide if the control module shall take any action.

The quality factor can be of the following status

1. OK The value indicates that the signal is normal and shows a credible status and accuracy.
2. Outside specified range Even though the value indicates that the signal is normal and may be usable, some fault has been detected that indicates that accuracy has been reduced so that performance may be affected or instability can occur.
3. No data found The value indicates that the signal has its initial start-up value and has not yet had time to receive measured or calculated value. This may occur when the control module's start-up process is not completely finished. As soon as the control module has started, the signal shall have a correct value. Receiving control module has a built-in delay to wait for correct signal.
4. No data exists The value indicates that the signal is faulty. This prevents the signal from being used by receiving control modules.

SUMMARY OF QUALITY FACTOR THAT MAY APPLY.

* Diagnostic trouble code may be stored.

COMPATIBILITY

The units must "speak" the same language and must be compatible with each other. A standardized communication protocol is used for this.

Signal configuration contains the language between the units. If any module has a signal configuration which does not correspond to other units the module cannot communicate. This means that all the units must have compatible signal configuration.

To check this the central electronic module transmits an identification number for its signal configuration over the controller area network. The other control modules receive this number and compare it with their own. If this identity does not correspond the control modules store a diagnostic trouble code. The signal configuration is occasionally modified so that the new messages are added and old messages removed.

CONFIGURATION

Instructions for the following are downloaded when a system is configured

1. Which control modules are included in the system
2. Which control module should do what
3. Which functions should be included
4. Which components are connected to the control modules
5. Which messages a control module is to transmit and which it is to receive
6. Where the different data should be stored.

The configuration must be changed after installing accessories and it must be downloaded again after replacing any control module. The information is stored and retrieved from Volvo's central database when downloading software.

Note. Even if two cars appear identical they may behave differently due to differing configurations, a parameter may have been modified by the customer or workshop.

CONSTRUCTION OF THE NETWORK

The network is made up of a number of control modules 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 the control modules are connected to a number of different spurs. 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. However, a failure in one of the spurs can lead to communication failure with one control module while communication in the rest of the same network is working.

Scheme 214

The network consists of two parts: a high speed side which transmits signals/messages between the central electronic module and control modules mainly in the engine compartment, and a low speed side which transmits signals/messages between the central electronic module 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 which converts the transmission speed up or down for communication between the two network sides.

Scheme 215

The data link connector is located in the passenger compartment near the driver's station. Cables for high-speed side and low-speed side are connected to the data link connector.

Scheme 216

1. Pin 3 LS CAN
2. Pin 4 Chassis ground
3. Pin 5 Signal ground
4. Pin 6 HS CAN
5. Pin 11 LS CAN
6. Pin 14 HS CAN
7. Pin 16 Voltage feed

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

TRANSMISSION SPEEDS

The Volvo control area network has two transmission speeds.

1. The HS CAN has a transfer speed of 500 kbit/s
2. The LS CAN has a transfer speed of 125 kbit/s.

1 kbit/s = 1024 bits per second.

For serial communication between a control module and a slave control module the transmission speed is 9.6 kbit/s.

TERMINATING RESISTOR

High-speed net HS CAN, example

Scheme 217

Low-speed net LS CAN, example

Scheme 218

To prevent electrical reflections and interference in the CAN network, there are terminating resistors which bridge CAN H and CAN L, one at each end on both the high and low speed sides of the network. Each terminating resistor has a resistance of 120 ohms.

1. For the HS CAN the terminating resistor is in the steering wheel module and the engine control module
2. For the LS CAN the terminating resistors are in the driver information module and the supplemental restraint system module.

Resistance measurement of parallel circuit with terminating resistor

Both the terminating resistors create a parallel circuit. The following resistances can be measured under specified conditions

1. When the control area network is intact the resistance on each side of the network is approximately 60 ohms.
2. In case of open circuits on the cables, so that a terminating resistor is not included in the circuit, the resistance in the net is approx. 120 ohm.
3. An open circuit on the cables to control modules located "outside" the measured circuit cannot be detected with this measurement.
4. In case of short-circuiting between the communication cables, the resistance is approx. 0 ohm between the cables, regardless of where the short-circuiting is located.

Scheme 219

Scheme 220

Scheme 221

The number of control modules in the CAN varies depending on the level of equipment, the vehicle model and the structure week.

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

ERROR MANAGEMENT IN THE CONTROLLER AREA NETWORK (CAN)

The control area network (CAN) is monitored and controlled by the central electronic module (CEM). When the central electronic module (CEM) detects a fault in the controller area network (CAN) a diagnostic trouble code (DTC) is stored in the central electronic module (CEM). There are different types of diagnostic trouble codes (DTCs) depending on the type of fault.

Fault types which are processed are

1. Electrical faults
2. No communication from a 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.

ELECTRICAL FAULTS

In the event of errors in the signal levels on the communication cables for the central electronic module (CEM) a diagnostic trouble code (DTC) is stored in the central electronic module (CEM). A check is carried out on each communication cable to the central electronic module (CEM), CAN L, CAN H on the low speed side and CAN L and CAN H on the high speed side. The faults that can be detected by the central electronic module (CEM) are

1. Short-circuit of controller area network (CAN) wiring to supply voltage
2. Short-circuit of controller area network (CAN) wiring to ground
3. Short-circuit between the control area network (CAN) cables
4. Open-circuit in the CAN H.

This allows a total of 12 electrical diagnostic trouble codes (DTCs) in the controller area network (CAN).

The diagnostic trouble codes for electrical faults are CEM-DF0X for the low speed network and CEM-DF1X for high speed network.

NO COMMUNICATION FROM A CONTROL MODULE

The central electronic module (CEM) knows which control modules are in the control area network and checks that all the control modules communicate. If any control module on the control area network (CAN) does not communicate a diagnostic trouble code is stored in the central electronic module (CEM). There is a diagnostic trouble code (DTC) for each control module. The diagnostic trouble codes (DTCs) are CEM-DEXX.

FAULTY COMMUNICATION

Each control module except for the central electronic module (CEM) has two diagnostic trouble code (DTC) types related to faulty communication. The central electronic module (CEM) only has one type of diagnostic trouble code (DTC).

These are

1. Faulty messages
2. Faulty configuration.

There is no diagnostic trouble code (DTC) for faulty configuration in the central electronic module (CEM) because the CEM is always the Master in the network.

Faulty messages

The diagnostic trouble codes (DTCs) for faulty communication are XXX-E000 for the high speed network and XXX-E001 for the low speed network.

The control modules continuously monitor the traffic on the controller area network (CAN). If a control module receives a message that it cannot interpret, it transmits an error message on the controller area network (CAN). This is called an Error-Frame. The control modules also have a function to detect faulty messages that they transmit themselves. This stops interference with other communication on the controller area network (CAN). If there is significant interference on the network the control modules that are not communicating properly can shut themselves down (this state is called Bus-Off). When a control module shuts itself down it neither receives or transmits information.

So that the vehicle does not suddenly stop and so that functions do not disappear entirely when controller area network (CAN) communication fails, certain control modules have a Limp-Home function. This means that control modules necessary for driving or safety (for example the engine control module (ECM) and transmission control module (TCM)) continue in a state of limited functionality with predefined or estimated values. As an example, if communication is lost with the transmission control module (TCM) the transmission will use a predefined gear. The intention here is that the customer can at least drive to a workshop. The control module remains in this mode until the power supply to the control module is switched off. When the power supply is connected the control module will make a new attempt to communicate.

Configuration fault

The diagnostic trouble code for configuration fault is XXX-E003.

The central electronic module (CEM) transmits its configuration ID in the frames it transmits to other control modules. For the control modules on the controller area network (CAN) to communicate with each other they must have the same configuration ID. This is because a control module only listens for messages containing its own configuration ID. If the signal configuration of a control module does not correspond to the signal configuration of the central electronic module (CEM), a diagnostic trouble code (DTC) is stored in the control module with the faulty signal configuration.

Note. This means that a control module will store diagnostic trouble code (DTC) XXX-E003 if it does not "hear" the central electronic module (CEM) at all. This also applies if there is a fault in the control module software. If there is an open-circuit in controller area network (CAN) this means that a control module cannot "hear" the central electronic module (CEM).

THE NETWORK

Increasing demands for further functionality in the vehicle, both by statutory requirement and customers, have led to an 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. Every command or message used to require 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.

ADVANTAGES OF A NETWORK

Easier to add further functions and install accessories

Because the control modules in the network are already connected to each other and are easy to add more information to, all that is required is

1. To connect the sensors to the nearest control module
2. To connect the controlled component to the nearest control module
3. To download software to the control module to modify the configuration.

The length of the wiring and the number of components which are introduced with the car is less than previously.

An example of this is the addition of cruise control for the car.

Before the introduction of the network the installation of control modules, switches, vacuum pumps, vacuum servos, hoses and cable harnesses was necessary.

With the network all that is required is the installation of a switch and the downloading of software which alters the configuration of the car.

Easier to introduce logical functions

Logical functions can be explained as "If this occurs then the following corrective action must be carried out". For example, the system is programmed so that if a tail light is broken, a message is transmitted via the control area network (CAN) to the driver information module (DIM) to warn the driver.

All that is required to introduce a logical function is to change the programming of the affected control module - the central electronic module (CEM) and driver information module (DIM) in the example above. Introduction of logic functions does not increase the number of components or cables.

Easy to adapt the system to customer and market requirements

The functions can be modified depending on the requirements of the customer and market. An example of this could be fog tail lamps. Certain markets use two fog tail lamps, others only use one on the driver's side. Previously it was required that different replacement parts were stored for different markets. Now the same replacement part can be used for all markets, by changing the programming depending on the market.

Similar basic systems can be used for a whole model program

Similar networks (hardware) can be used for a large number of different cars.

The only thing which differentiates the cars is

1. Which components (control modules, sensors controlled components etc.) are connected to the system
2. Which components do what
3. Which components/functions are standard /optional/accessories
4. Configuration/programming of the system.

Scheme 222

The purpose of the tire pressure monitoring system, TPMS, is to enable the driver to have optimum tire pressure by giving a warning when the pressure in any of the tires becomes too low. Correct tire pressure is important for

1. achieving good fuel economy
2. achieving optimum comfort and good driving characteristics
3. preventing flat tires due to too low tire pressure.

The function is integrated in the central electronic module (CEM). Sensors are installed together with the air valve on each wheel to measure the air pressure in the tires.

Note. The system must be regarded as a driver aid to maintain the correct tire pressure. The system must NOT be regarded as a warning system that indicates that there is a serious problem with the vehicle. No tire is completely sealed - there is always slight leakage as the tire can never be completely sealed to the rim. When inflating the tire with air, you must, as much as possible, ensure that the tires are at same temperature as the outside temperature. Furthermore, "Comfort pressure" should not be applied as this gives a tire pressure that is too close to the parameter for the monitoring system, which means that even small changes in temperature or load can cause the pressure in the tires to be too low for the system to consider acceptable. When inflating with air, the tires must be filled to the pressure stated on the decal located on the car body. The pressure is calculated with regard to fuel economy, comfort and safety. Therefore, these pressures MUST be followed. If the decal is missing or damaged, a new one must be ordered and applied. This is especially important on vehicles with TPMS.

Scheme 223

The tire pressure sensors are installed together with the air valve on the rim. The sensor consists of a pressure sensor, a communication circuit, an acceleration sensor and a battery.

Note. Special procedures are required for removing the tire from the rim depending on vehicle model and tire type. This is to prevent damaging the sensor.

TIRE PRESSURE MONITORING SYSTEM (TPMS)

The central electronic module (CEM) can store diagnostic trouble codes (DTCs) if there is a fault in the receiver or a fault in any of the sensors. In order to carry out a correct evaluation of the function, the vehicle must have traveled faster than 40 km/h (25 mph) for longer than 570 seconds (approximately 9.5 minutes). This time is accumulated time, i. e. the time is interrupted if the vehicle drops below 40 km/h (25 mph), if stopping at traffic lights for example. Counting continues as soon as the vehicle exceeds 40 km/h (25 mph) again.

The central electronic module (CEM) can store two diagnostic trouble codes (DTCs) per sensor. A diagnostic trouble code (DTC) for lost communication when traveling, a diagnostic trouble code (DTC) for low battery voltage and a diagnostic trouble code (DTC) when a learned sensor is not obtained during the current operating cycle. Diagnostic trouble codes (DTCs) are also stored if the configuration of the system is not carried out, fails or is interrupted.

When a diagnostic trouble code (DTC) is stored, the ID number of the sensor that applies to the diagnostic trouble code (DTC) is also stored. When a diagnostic trouble code (DTC) is stored, a message is shown in the driver information module (DIM).

CONFIGURATION OF THE TPMS SYSTEM

The TPMS system is self-learning. This means that when the vehicle is driven and the sensors transmit messages, the Central electronic module (CEM) receives and registers the ID numbers that the sensors transmitted.

After a process of elimination during a certain period, the Central electronic module (CEM) then decides that the sensors with the four most frequently received ID numbers belong to the vehicle.

There are two diagnostic procedures that can be activated from the diagnostic tool to make the system fully functioning from the factory or if any remedial actions has been carried out at the workshop.

1. EOL test (End Of Line, factory test). The procedure is run after the ID number has been programmed in the vehicle. The purpose of this is to check that the entire chain with receiver, Central electronic module (CEM) and Driver information module (DIM) function and that the vehicle can receive transmissions from the sensors when the last tests are run in the factory.
2. WS test (Workshop test). The procedure is used to program new IDs to the Central electronic module (CEM) and to check that the system functions correctly. For example, when a sensor has needed to be replaced or if the Central electronic module (CEM) has been replaced.

The differences between the two procedures are that the factory tests only finish OK after the four sensor IDs that are already programmed have been received properly. The workshop test finishes OK as soon as the four sensor IDs have been received.

Note. During the workshop test, it is important to check that no other tests are running around the vehicle. There is a risk that a sensor ID from another vehicle is received by the vehicle being programmed.

Scheme 224

The system can be checked using the diagnostic tool by activating a read out at the same time as activating the sensors using a special tool. The special tool is positioned against the tire, where the sensor is located, at the same time as a button is pressed on the special tool. The special tool transmits a signal that activates the sensor so that it starts transmitting signals to the central electronic module (CEM). The activated sensor's ID number and tire pressure is then shown in the display in the diagnostic tool.

Note. The special tool for TPMS on S80 (-06)/S60/V70/XC70/XC90 does not work with the sensors on S40 (04-)/V50/C30/C70 (06-).

Scheme 225

The system contains the central electronic module (CEM) (4/56), Remote Receiver Module (RRX) (4/119) (or remote keyless entry (RKE) if the function for keyless function is installed) and sensors mounted in the wheels. The sensors in the wheels are activated when the vehicle exceeds 40 km/h (25 mph). The sensors then start transmitting data messages approximately once every minute, which are received by the receiver. The signals are then transmitted onwards to the central electronic module (CEM). These messages contain information about the identity number of the sensor and the air pressure of each tire.

The transmitting frequency of the sensors is the same for all sensors. The control module can receive signals from other vehicles with the same system installed. Therefore, the ID number in each sensor is unique. The sensors that are mounted on the actual vehicle are determined via a statistical elimination procedure in the central electronic module (CEM).

When the ignition is switched on the Remote Receiver Module (RRX) (Remote Keyless Entry (RKE) if the keyless function is installed) starts to listen for messages from the sensors. The signals transmit the receiver to the Central electronic module (CEM).

The control module registers the ID numbers that are in the received messages, which the sensors transmit, both from the actual and from other vehicles. All ID numbers that are received are placed in a list in the central electronic module's (CEM) internal memory. For each ID number that is received, the number of times that ID number is received is stored as well.

Because the number of received ID numbers increases, an evaluation of which ID numbers were received the most times is carried out. The ID numbers received the most times receive the highest "rank" and are then considered to belong to the actual vehicle. In this way, there is differentiation between any ID numbers that have been received from other vehicles with the same type of system, which have, for example, been driven in another lane next to the actual vehicle.

This evaluation takes a maximum of approximately 10 minutes if the Central electronic module (CEM) has no data.

If the evaluation has been carried out, the sensors that are assumed to belong to the actual vehicle are stored in the control module. The information remains between each driving cycle. In this case, it is sufficient for the control module to receive a message from each sensor with corresponding ID number to complete evaluation.

There are programmed tables in the central electronic module (CEM) containing the recommended air pressure for that vehicle model. The information about the air pressure in the tires found in the messages transmitted from the sensors, is compared with the programmed values in the central electronic module (CEM). If the pressure, which was reported from a sensor, deviates too much from the recommended value a warning message is displayed in the driver information module (DIM) (5/1).

There are two warning levels that generate different warning messages, one warning for low pressure and a warning for very low pressure.

A message is also displayed if a sensor stops transmitting or receives insufficient battery voltage.

A warning lamp also lights in the Driver information module (DIM) at the same time as the warning message appears.

The easiest way to reset a warning is to stop the vehicle, fill the tire with low pressure with air. The warning in the Driver information module (DIM) disappears the next time the ignition is switched on.

If air is filled in a tire that has warned of low pressure and the ignition is on during the entire process, the warning will go out as soon as the pressure in the tire exceeds the normal level.

If a sensor must be replaced for a tire that has warned of low pressure, the system must "learn" the new sensor ID. This can be carried out in different ways

1. Drive the vehicle faster than 40 km/h (25 mph) for longer than 10 minutes. The warning for low pressure remains in the Driver information module (DIM) until the Central electronic module (CEM) has identified the new sensor.
2. Programming "by hand". This is carried out using the function in VIDA (Volvo scan tool).

Note. The vehicle must be parked for longer than 15 minutes to learn the new ID.

TIRE PRESSURE MESSAGES

The tire pressure warning function is checked by the central electronic module (CEM). The system must give a warning to driver in the driver information module (DIM) display if the air pressure in one of the tires is lower than the predetermined parameter.

The table below summarizes the input signals to and output signals from the central electronic module (CEM). The signal types are divided into serial communication and controller area network (CAN) communication. No directly connected signals are included in the function.

CENTRAL ELECTRONIC MODULE (CEM) (4/56)

Scheme 226

The traffic message channel module (TMC) stores a list of the stations (or frequencies) found during the most recent search. When started, the control module tunes to the last set station. If there is no information about the station, the control module will search automatically starting at 99.4 MHz. If a new TMC station is found that is not already in the list, this station is stored automatically.

If the signal from the present frequency does not contain any RDS data, the control module will automatically begin a new search. The search continues until a station is found which transmits traffic messages. If the control module does not find any TMC stations, the control module returns to the last set frequency.

Automatic searching only takes place if none of the stations in the stored list have better reception than the station currently tuned in. During automatic searching, the list of saved stations is erased and a new list is created. Automatic searching may take up to 10 minutes.

The traffic message channel module (TMC) is controlled via the menu system in the multimedia module (MMM).

When the ignition is switched off the power consumption of the traffic message channel module (TMC) and antenna must not exceed 0.1 mA.

The system can endure temperatures between -40 °C and 85 °C.

The control module checks the input and output signals through an integrated diagnostic system.

The control module communicates with directly connected components, and via MOST communication.

Scheme 227

On the S40 a combined AM/FM (main and sub) and TMC-antenna is used. The antenna is integrated in the rear windshield.

There is a combined AM/FM main antenna integrated in the right door window. There is also an antenna for FMsub, which s a combined FMsub/TMC antenna integrated in the rear window.

On the C70 there are two antennas. A combined AM/FM rod antenna, which is integrated on the rear right-hand side. An FMsub antenna, which is a combined FMsub/TMC antenna and is behind the bumper.

The frequency range of the antenna is 87.5 - 108.0 MHz.

The signals from the antenna are amplified or adjusted by an antenna amplifier.

The antenna amplifier transmits TMC/FM sub-signals on to the Traffic message channel module (TMC). The FM sub-signals are then transmitted to the AM/FM tuner module (AFM) (applies to vehicles with structure week up to and including 200445) or Integrated Audio Module (IAM) (applies to vehicles with structure week from and including 200446).

This function can be used to continuously read off the values and status of the control module's input and output signals.

The following parameters can be read off

1. TMC Frequency. Indicates the frequency the TMC receiver is set to
2. Signal strength TMC. Indicates the strength of the TMC signal.

This function can be used to read parameters, status identifiers and counters stored at the same time as a diagnostic trouble code (DTC). These are called frozen values.

New software can be downloaded into the traffic message channel module (TMC). When ordering software, the hardware and the software in the car is compared to the information in the Volvo central database. If the comparison is OK the software is downloaded to the control module.

If the comparison between the car and Volvo central database is not OK, the database is updated with the car configuration. When this is complete the software is downloaded.

In C70, the traffic message channel module (TMC) is located behind the right wheel housing.

After replacing a control module, the unique ID number of the control module must be programmed in the central electronic module (CEM).

Scheme 228

The traffic message signal which is transmitted via radio is received by the antenna. The signal is sent onwards via the antenna amplifier (16/16) to the traffic message channel module (TMC) (16/49). The traffic message channel module (TMC) sends the signal onwards via the MOST network to the receiver in the multimedia module (MMM) (16/108).

The multimedia module (MMM) presents this information on the directly connected display (16/46).

Scheme 229

The traffic message channel module (TMC) is an option only available in the European market for vehicles with a navigation system. The traffic message channel module (TMC) receives radio transmitted traffic messages.

TMC (Traffic Message Channel) is a standardized code system for traffic messages giving information about road repairs, traffic queues etc.

In C70, the traffic message channel module (TMC) is located behind the right wheel housing.

The control module uses optical serial communication to communicate with other components on the MOST network. This means that all communication with the control module is via the infotainment control module (ICM).

Any diagnostic trouble codes (DTCs) are stored in the control module memory. This information can be read off using VIDA (Volvo scan tool) via the data link connector (DLC) in the vehicle.

The table below summarizes the input signals to and output signals from the traffic message channel module (TMC). The signal types are divided into directly connected signals and MOST communication. The illustration below (Scheme 230) displays the same information with the Volvo component designations.

Scheme 230

Scheme 231

The trailer module (TRM) manages the electrical connection between the vehicle and the trailer.

The primary task of the control module is to manage output signals to the tow hitch cable harness for

1. Turn signal lamps
2. Brake light
3. Parking lamps
4. Back-up lamp
5. Fog lamps
6. +12 V.

The trailer module (TRM) communicates on the controller area network (CAN) with

1. central electronic module (CEM)
2. driver information module (DIM)
3. differential electronic module (DEM) (option)
4. parking assistance module (PAM) (option).

Scheme 232

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 stores any diagnostic trouble codes (DTCs). The diagnostic trouble codes (DTCs) can then be read using VIDA (Volvo scan tool). Information is presented in VIDA in the same way as with other diagnostic systems.

If a fault arises in the tow hitch system the driver is warned via the driver information module (DIM) when the information lamp lights and an alert message is displayed.

A VIDA (Volvo scan tool) station must be connected to the data link connector (DLC) in order to identify the source of the fault.

Data can be read off from the trailer module (TRM) using this function.

Battery voltage

Reads off the level of the power supply to the control module.

Input signal

Reads out the status of the stop lamp signal from the vehicle's right tail lamp.

Output signals

Reads out the status of the output signals to the cable harness for the tow hitch.

Tow hitch connector

Reads out whether the tow hitch connector is connected to the socket on the cable harness for the tow hitch.

A new trailer module (TRM) is not preprogrammed. New software must always be downloaded.

New software can be downloaded into previously installed control modules.

When downloading new software a P/N must be entered. This must be done to obtain the correct software and full operation of the control module. The P/N corresponds to the type of socket used on the cable harness for the tow hitch.

Scheme 233

The trailer module (TRM) (4/110) ensures that the correct type of signals are transmitted to the tow hitch cable harness.

The trailer module (TRM) receives messages on the controller area network (CAN) from the central electronic module (CEM) (4/56) regarding when output signals to the turn signal lamps, parking lamps, back-up (reversing) lamps and fog lamps should be activated.

The stop lamp signals are directly connected from the vehicle's right-hand tail lamp.

The trailer module (TRM) forwards the signal to the tow hitch cable harness.

The output signal for +12 V voltage is activated when the ignition key /starter knob is turned from position 0 to I, II or III. The trailer module (TRM) transmits the signal via a relay and an separate fuse.

The trailer module (TRM) transmits messages on the controller area network (CAN) to the central electronic module and driver information module, regarding the status of the trailer stop lamps. If the stop lamp bulbs are defective the information lamp in the driver information module lights and a warning message is displayed.

The trailer module transmits messages on the controller area network to the central electronic module, driver information module, differential electronic module and the parking assistance module if a trailer is connected to the tow hitch connector socket. A separate indicator lamp in the driver information module indicates when the turn signal lamps are used and the trailer is connected. If one of the turn signal lamp bulbs is defective the separate indicator lamp will not light.

The output signals for back-up lamps, fog lamps and +12 V in the socket for the tow hitch connector are market dependent. The socket for the tow hitch connector is available in a number of variants with different numbers of pins.

The trailer module manages the electrical connection between the vehicle and the trailer.

The control module is located in the cargo compartment, behind the right wheel arch.

The trailer module communicates with directly connected components and with other control modules via the controller area network.

The control module checks the input and output signals through an integrated diagnostic system. A diagnostic trouble code is stored if the control module detects a fault. Any diagnostic trouble codes are stored in the control module memory. The data can be read off using VIDA (Volvo scan tool).

An easy way to check if the control module has power and is grounded, is to switch on the ignition and the turn signal lamps when the tow hitch connector is connected to its socket. The driver information module indicator lamp lights and the trailer turn signal lamps should flash as they do on the vehicle. The trailer's connectors, cable harness and lights must not be damaged or defective when this check is carried out.

For further information, see SIGNALS .

The table below summarizes the input signals to and output signals from the trailer module. The signal types are divided into directly connected signals and CAN communication. The illustration below (Scheme 234) displays the same information with the Volvo component designations.

Scheme 234

Scheme 235

The automatic transmission has five forward gears and one back-up gear. The fifth gear is an overdrive which saves fuel during highway driving.

The mechanical components of the transmission are enclosed within the torque converter cover, the transmission housing and valve housing.

Gearshifts are controlled by an hydraulic operating system. Gearshifts take place without freewheeling and completely automatically in terms of load and speed.

The solenoid valves are located under the valve housing cover on the transmission, in the valve housing for the hydraulic system. These are activated by the transmission control module.

The transmission input speed sensor is electro-magnetic and acts on a toothed pulse wheel. By comparing the engine and transmission speeds, the control module can determine the amount of slippage in the torque converter.

The gear-shift position sensor has three separate functions

1. using an electrical route to inform the transmission control module of the selected gear position
2. to activate the back-up light when the gear selector is in -position
3. To allow engine start if the gear selector is in or -position. This signal is also transmitted to the engine's control system and is used for drive position compensation of idle.

The transmission and final drive share a common oil pan. A dipstick in the transmission is used to check the oil level in the transmission.

Scheme 236

The torque converter is between the engine and the automatic transmission.

When the engine is idling the pump effect is too weak to drive the turbine and the vehicle will not move. As the engine speed rises it successively starts to drive in a gradual way. At higher engine speeds the power transfer to the turbine can be up to 95%. The torque converter functions as an hydraulic clutch. It also amplifies the torque of the engine at lower engine speeds and therefore an automatic transmission does not require as many gears as a manual transmission.

The torque converter consists of a round metal casing which contains two impeller wheels and is filled with oil. One of the impeller wheels, the pump wheel, is fixed to the casing. Both are connected to the engine crankshaft and rotate with it. The other impeller wheel, the turbine wheel, is connected to the input shaft of the transmission and is driven by the oil which is pumped around by the pump wheel. The rotating impeller wheels and the oil in the torque converter "slip" slightly and creates a slight loss of power, which raises fuel consumption slightly.

Thanks to a third, smaller wheel, the stator wheel, the torque converter also reinforces the engine torque at low engine speeds.

Scheme 237

The differential distributes power equally between the drive wheels, even if they are rotating at different speeds.

The differential consists of the differential housing, large and small side gears, shaft journals and thrust washers.

The differential has 6 gearwheels. The differential housing is completely sealed so that if a drive shaft is removed no dirt can penetrate and no oil can run out.

TRANSMISSION, GENERAL

The basic parameters for shifting are the accelerator pedal position and the vehicle speed.

The gear shift quality is determined by the torque control by reading off speed changes of the transmission input shaft and comparing the calculated value.

This is used to calculate the pressure setting for the clutches and brakes.

DIFFERENTIAL

The differential distributes power equally between the drive wheels, even if they are rotating at different speeds.

When driving straight ahead, the ring wheel and differential housing rotate at the same speed as the drive shafts and the driving wheels.

When cornering, the differential gears rotate to compensate for the different speeds of the wheels. Because the small side gears are rotating on the shaft journal, the drive shafts can rotate at different speeds. Power is transferred from the differential housing to the drive shafts via the small side gears in the same way as when driving straight ahead. Both drive wheels still have the same driven power.

Cars with four wheel drive have a splined pin on the differential housing. The sleeve on the pin connects the differential housing with the bevel gear. This transfers the power to the rear wheels.

Scheme 238

Scheme 239

The gear selector assembly is positioned in the center console and is mechanically connected to the transmission by a cable which affects the gear valve.

Gear selectors and cables are shaped differently depending on which car model they are installed in.

Gear selector assemblies with Geartronic, in addition to P/R/N/D modes, also have a manual shifting mode. The manual gear positions can be selected at any point while driving. The engaged gear is locked until the driver selects another gear. The automatic transmission only down shifts if the vehicle slows down to very low speed.

To downshift the gear selector must be moved to minus. To upshift the gear selector must be moved to plus. At start, 3rd is the highest possible gear.

The engine can only be started in position P or N .

THE DIFFERENT GEAR SELECTOR POSITIONS

POWER FLOW

When throttling off, the output shaft's power in 5th, 4th, 3rd, 2nd or reverse gear goes directly to the input shaft without any freewheel, which provides engine braking. 1st gear does not have any engine braking since the power transmission is interrupted by freewheel.

Position

Scheme 240

Primary shaft

The input shaft rotates clockwise. All clutches and brakes are disengaged, and no power is transferred to the planetary trains.

Output shaft

No power is transmitted to the output shaft. Brake band locks the sun gear so that it cannot rotate in any direction. Shiftlock, which is affected by the mechanical link system, is engaged with the lock wheel on the output shaft and prevents the vehicle from rolling.

Position

Scheme 241

Primary shaft

The input shaft rotates clockwise. All clutches and brakes are disengaged, and no power is transferred to the planetary trains.

Output shaft

No power is transmitted to the output shaft. Brake band locks the sun gear so that it cannot rotate in any direction. Shift-lock is disengaged. The planetary gears can rotate freely around the sun gear and the vehicle will start to roll if it is on an incline.

The reason for the brake being activated in both as -position is to minimize the engagement shock that otherwise is produced when several brakes and clutches are activated at the same time when the gear selector is moved to or -position. Since is still activated in both first gear and reverse, in this way simultaneous engagements are reduced.

Position and 1st gear

Scheme 242

Main section

The input shaft rotates clockwise. Clutch connects the input shaft to the rear ring gear, which rotates clockwise. The rear planetary gear rotates clockwise. The front large planetary gear rotates clockwise with the rear planetary gear as a unit.

The front small planetary gear rotates clockwise. The front ring gear rotates counter-clockwise. Freewheel locks the front ring gear's rotation counter-clockwise.

The front and rear planetary carriers are turned clockwise because of the reactive forces from the small gear. The primary intermediate gear rotates clockwise with the front and rear planetary carriers as a unit.

U/D section

The secondary intermediate gear rotates counter-clockwise. The front ring gear rotates counter-clockwise with secondary intermediate gear as a unit.

The front planetary gear rotates clockwise. The front planetary gear rotates clockwise. The rear sun gear rotates clockwise with the front sun gear as a unit.

The rear planetary gear rotates counter-clockwise. Brake locks the rear planetary carrier's rotation. The rear ring gear rotates counter-clockwise. The front planetary carrier and final drive pinion rotates counter-clockwise with the rear ring gear as a unit. The final drive rotates clockwise.

Engine brake

The primary intermediate gear and front and rear main planetary carriers rotate clockwise. The rear planetary carrier rotates clockwise. The rear planetary gear is turned counter-clockwise while it rotates counter-clockwise because of the resistance from the rear ring gear.

The front large gear wheel is turned clockwise while it rotates counter-clockwise and the small gear wheel is turned clockwise while it rotates clockwise. The front planetary carrier is turned clockwise.

The front ring gear rotates clockwise because the front small gear rotates clockwise, but drive force is reduced because freewheel is disengaged. Therefore the engine brake does not operate.

Position and 2nd gear

Scheme 243

Main section

The input shaft rotates clockwise. Clutch connects the input shaft to the rear ring gear. The rear ring gear rotates clockwise. The rear planetary gear rotates clockwise.

The front large planetary gear rotates clockwise with the rear planetary gear as a unit. Brake, freewheel and brake lock the sun gear's rotation.

The front and rear planetary carriers are turned clockwise because of the reactive forces from the front large gear. The primary intermediate gear rotates clockwise with the front and rear planetary carriers as a unit.

U/D section

The secondary intermediate gear rotates counter-clockwise. The front ring gear rotates counter-clockwise with the secondary intermediate gear as a unit. The front planetary gear rotates clockwise. The front planetary gear rotates clockwise.

The rear sun gear rotates clockwise with the front sun gear as a unit. The rear planetary gear rotates counter-clockwise. Brake locks the rear planetary carrier's rotation. The rear ring gear rotates counter-clockwise.

The front planetary carrier and final drive pinion rotates clockwise with the rear ring gear as a unit. The final drive rotates clockwise.

Engine brake

Drive force is transferred directly to the input shaft without the one way clutch. Therefore the engine brake operates.

Position and 3rd gear

Scheme 244

Main section

The input shaft rotates clockwise. Clutch connects the input shaft to the rear ring gear. The rear ring gear rotates clockwise. The rear planetary gear rotates clockwise.

The front large planetary gear rotates clockwise with the rear planetary gear as a unit. Brake, freewheel and brake lock the sun gear's rotation.

The front and rear planetary carriers are turned clockwise because of the reactive forces from the front large gear. The primary intermediate gear rotates clockwise with the front and rear planetary carriers as a unit.

U/D section

The secondary intermediate gear rotates counter-clockwise. The front ring gear rotates counter-clockwise with the secondary intermediate gear as a unit. The front planetary gear rotates clockwise. Brake locks the rotation of the front and rear sun gear.

The front planetary carrier is turned clockwise because of the reactive forces from the front large planetary gear. The front planetary carrier and final drive pinion rotate clockwise with the rear ring gear as a unit. The final drive rotates clockwise.

Engine brake

Drive force is transferred directly to the input shaft without the one way clutch. Therefore the engine brake operates

Position and 4th gear

Scheme 245

Main section

The input shaft rotates clockwise. Clutch connects the input shaft to the rear ring gear. The rear ring gear rotates clockwise. The rear planetary gear rotates clockwise.

The front large planetary gear rotates clockwise with the rear planetary gear as a unit. Brake, freewheel and brake lock the sun gear's rotation.

The front and rear planetary carriers are turned clockwise because of the reactive forces from the front large gear. The primary intermediate gear rotates clockwise with the front and rear planetary carriers as a unit.

U/D section

The secondary intermediate gear rotates clockwise. The front ring gear rotates counter-clockwise with the secondary intermediate gear as a unit. Clutch C3 connects the sun gear to the front planetary carrier.

The front planetary gear cannot rotate and the U/D unit rotates counter-clockwise as a unit. The final drive pinion rotates counter-clockwise with the U/D unit as a unit. The final drive rotates clockwise.

Engine brake

Drive force is transferred directly to the input shaft without the one way clutch. Therefore the engine brake operates.

Position and 5th gear

Scheme 246

Main section

The input shaft rotates clockwise. Clutch connects the input shaft to the rear ring gear. Clutch connects the input shaft to the sun gear.

The rear planetary gear cannot rotate and the rear planetary gear unit rotates clockwise as a unit. The front planetary gear cannot rotate with the rear planetary gear as a unit. The front planetary unit rotates clockwise as a unit. The primary intermediate gear rotates clockwise with the front planetary unit as a unit.

U/D section

The secondary intermediate gear rotates counter-clockwise. The front ring gear rotates counter-clockwise with the secondary intermediate gear as a unit. Clutch connects the sun gear to the front planetary carrier.

The front planetary gear cannot rotate and the U/D unit rotates counter-clockwise as a unit. The final drive pinion rotates counter-clockwise with the U/D unit as a unit. The final drive rotates clockwise.

Engine brake

Drive force is transferred directly to the input shaft without the one way clutch. Therefore the engine brake operates.

Position

Scheme 247

Main section

The input shaft rotates clockwise. Clutch connects the input shaft to the sun gear. The sun gear rotates clockwise.

The rear planetary gear rotates counter-clockwise. The front large planetary gear rotates counter-clockwise with the rear planetary gear as a unit. The front small planetary gear rotates clockwise.

Brake locks the front ring gear's rotation counter-clockwise. The front and rear planetary carriers are turned clockwise because of the reaction forces from the front small gear. The primary intermediate gear rotates counter-clockwise with the front and rear planetary carriers as a unit.

U/D section

The secondary intermediate gear rotates clockwise. The front ring gear rotates clockwise with the secondary intermediate gear as a unit. The front planetary gear rotates clockwise. The front sun gear rotates counter-clockwise.

The rear sun gear rotates counter-clockwise with the front sun gear as a unit. The rear planetary gear rotates clockwise. Brake locks the rear planetary carrier's rotation. The rear ring gear rotates clockwise. The front planetary carrier and final drive pinion rotate clockwise with the rear ring gear as a unit. The final drive rotates counter-clockwise.

Engine brake

Drive force is transferred directly to the input shaft without the one way clutch. Therefore the engine brake operates.

TOWING

Towing is only permitted in the vehicle's forward direction at max. 80 km/h for max. 80 km.

The gear selector shall be in position.

Scheme 248

AW55-51 is a 5 speed electronically controlled automatic transmission with a lock-up function for the three highest gears. The transmission control module (TCM) adapts the gear changes to ensure that the correct gear is selected for the driving mode, engine load, driver requirements, speed etc. This gives good fuel economy combined with increased comfort by ensuring smoother gear changes and lower noise levels.

In a vehicle with an automatic transmission, the driver neither needs to decide which gear should be used nor shift gear. There is a operating system in the AW55-51 which uses a torque converter and gear shift system to do this.

Scheme 249

M66 is a six gear manual transmission. All gears, including back-up (reverse), are synchronized. The transmission is intended to be part of a transverse drive line with front wheel or four wheel drive.

The transmission is built together with the final driven in a common aluminum housing. This unique construction makes the transmission very compact while enabling it to transmit high torque.

The engine and transmission have damped mountings, either on the side members with pendulum mounting or on a sub frame.

The transmission and final drive are extremely compact.

The oil is synthetic and does not normally need to be changed. The oil is heat resistant and tolerates high loads. The hole in the level plug is used to top up the oil and check its level. The oil is drained through the drain plug in the base of the transmission.

The gear wheels are located on four shafts. They are

1. input shaft (A)
2. intermediate shaft 1-2, 5-6 (B)
3. intermediate shaft 3-4 (C)
4. back-up (reverse) shaft (D).

The clutch gears are welded directly to the idler wheel to shorten the length of the shaft. To further shorten the length of the transmission, needle bearing with inner rings are used instead of snap rings.

The inner rings sit on the shaft inside the idler gears and extend lengthwise a little outside each idler gear. When the components on the shafts are pulled together the inner rings counterhold, so that the idler wheels have the clearance that they require to rotate.

The components of the input shafts are pulled together with a bolt located in the end of the shaft. Components of intermediate shaft 3-4 are held together with a press joint and a bolt located in the end of the shaft. The components of intermediate shaft 1-2, 5-6 are held together with the press joint of the 5th and 6th gear pinion.

Scheme 250

Scheme 251

The gear selector is in a single complete unit with the exception of the ball limiter for the gear position. This is threaded in the transmission housing. The gear selector is held in position by 4 screws. 2 guide pins in the control housing and a needle bearing in the bottom of the gear selector unit control the position in the transmission housing.

Back-up (reverse) gear in the gear selector assembly is furthest to the right and down. Neutral is between 3rd and 4th.

The back-up (reversing) lamp switch is in the control housing and is affected by the shaft for lateral movement. The back-up (reversing) lamp switch is directly connected to the central electronic module (CEM).

The gear selector unit must not be dismantled. In the event of a fault the whole gear selector unit must be replaced.

4 gear selector forks transfer the movement from the control to the relevant coupling sleeve.

Scheme 252

1. Locking the adjustable mechanical transmission cable for lateral travel
2. Solenoid
3. Gear selector assembly
4. Mechanical cables
5. Mechanical cables bracket.

The mechanical cables are in a cable assembly. In the event of a fault or damage with any of these the whole mechanical cable assembly must be replaced.

The cable sleeves are secured using quick connectors in the gearshift assembly and in the cable bracket on the transmission.

The mechanical transmission cable for lateral travel is adjustable lengthwise. The adjuster is positioned on the mounting towards the lever on the transmission (1).

The gear selector assembly is made of plastic. It has rubber feet (to reduce noise and vibration).

The gear selector assembly has a lever and a lever arm. There is a return spring on the lateral movement lever.

BACK-UP (REVERSE) INHIBITOR

The shift lever assembly houses a solenoid that serves as an electronically controlled reverse inhibitor.

There is an electronic damping function on the solenoid which gives the solenoid a soft action. This reduces noise. The solenoid can be replaced.

The differential distributes drive shaft torque equally between the drive wheels, even if they are rotating at different speeds.

The differential consists of the differential housing, large and small side gears, shaft journals and thrust washers.

Applies to AWD

On the M66 AWD a sleeve for power transfer is located on the differential.

SYNCHRONIZATION

The synchronizing hub assembly consists of a coupling sleeve, flange and the hub. Each synchronizing hub is joined to its shaft by splines and rotates with it.

There are idler wheels on both sides of each synchronizing hub. The idler wheels rotate freely on the shaft (does not apply to reverse gear). Each idler wheel is constantly engaged in its pinion. The synchronizing set is positioned between the synchronizing hub and the idler wheel.

The synchronizing units are positioned on the shafts in the transmission as follows

1. The synchronizing unit for 1st - 2nd gear is on the intermediate shaft 1-2, 5-6
2. The synchronizing unit for 3rd - 4th gear is on the intermediate shaft 3-4
3. 5th-6th the synchronizing unit is on the input shaft
4. the synchronizing unit for back-up (reverse) gear is on the back-up (reverse) shaft.

The synchronizing rings expand when heated by the same amount as the components they are in contact with. As a result no safety margin is required to counter expansion.

The idler wheels for single and double synchronization have no cones. An inner ring on the synchronizer unit performs this function instead.

The synchronizer unit is a modular system. This makes it easy to upgrade from a single synchronizer to double synchronization by replacing the synchronizer kit.

Scheme 253

Single synchronization , which has one friction surface, is on

1. back-up (reverse) gear
2. 4th gear
3. 5th gear
4. 6th gear.

The outer ring (to the left in the illustration) is manufactured in pressed steel. The inner ring is pressed steel and the friction surface is coated with brass.

Scheme 254

Double synchronization , two friction surfaces, is on

1. 3rd gear.

The outer ring (to the left in the illustration) is manufactured in pressed steel. The sealing ring is pressed steel and the friction surfaces are coated with brass. The inner ring is machined steel.

Scheme 255

Triple synchronization , three friction surfaces, is on

1. 1st gear
2. 2nd gear.

The outer ring (to the left in the illustration) is made of pressed metal. The intermediate ring is made of pressed metal with a brass coating on the friction surfaces. The inner ring is of pressed metal with a brass coating on the inner friction surface. Triple synchronization also includes a ring integrated with the idler wheel.

Scheme 256

The main task of the clutch system is to transfer torque, disengage during shifting, allow comfortable starting and to act as an efficient vibration damper to eliminate noise and vibration in the chassis and drive train.

The clutch is located between the engine and the transmission. The main components are a pressure plate and a clutch driven plate. The clutch is used to connect the torque from the engine to and from the transmission and therefore to drive the wheels.

The clutch is a single disc dry clutch. The clutch disc is connected to the transmission input shaft on the transmission.

On vehicles with more powerful engines, self-adjusting clutches are used to lower the engagement forces.

Scheme 257

The clutch control mechanism is fully hydraulic. The slave cylinder is inside the clutch cover. There is no mechanical transfer (fork) inside the clutch cover from an external slave cylinder.

The concentric slave cylinder (CSC) means that the slave cylinder is integrated with the throwout bearing.

The concentric slave cylinder (CSC) is extremely efficient and reliable and the throwout bearing is accurately centered.

The unit is mounted with a bolt in the gearcase. The bearings and sliding surfaces do not require lubrication. The bearing on the concentric slave cylinder is self-centering to the clutch fan.

The hydraulic line from the master cylinder is connected to the concentric slave cylinder (CSC) via an adapter. There is a bleed nipple on the adapter.

There are ratios built-in to the system to reduce the force required to transfer torque

1. pedal effort
2. hydraulic force
3. clutch finger force.

The force is reduced from approximately 8600 N at the clutch to approximately 100 N at the pedal.

If the clutch pedal returns too quickly, the drive line could be damaged by the high torque. There is a shock load limiter in the clutch to avoid this. The shock load limiter chokes the flow between the concentric slave cylinder (CSC) and the master cylinder if there is a danger of the excessive torque. The shock load limiter is in the concentric slave cylinder.

Scheme 258

In vehicles with engines with high engine torque the return time of the clutch pedal may be too short. This means that the torque peak is so high that it can damage the driveline.

In the event of the torque peak being to high, the hydraulic flow in the engagement direction is choked between the concentric slave cylinder (CSC) and the master cylinder using a shock load limiter.

Scheme 259

A self-adjusting clutch (SAC) eliminates problems both in terms of wear in the clutch cover and the need for increased force at the pedal as the facing thickness reduces.

This considerably increases the life of the clutch. A self adjusting clutch will not normally require replacement during the lifetime of the vehicle.

A self-adjusting clutch (SAC) senses the increase in release load at the diaphragm spring. It has a adjustment mechanism between the diaphragm spring and the clutch housing. This maintains the position of the diaphragm spring and ensures that the pedal effort required remains constant throughout the service life of the vehicle.

The pressure plate is of the diaphragm spring type. Unlike a traditional type, the pressure plate contains an adjustment ring made of steel or plastic. If there is wear, the adjustment ring moves slightly to maintain the engagement position of the clutch.

The fact that the fingers are unable to move backwards has the following advantages

1. increased wear capacity
2. the clutch cover can be made shorter because space is not required for rearward movement of the diaphragm spring.

Scheme 260

The clutch driven plate is the component that transfers the torque to the input shaft and into the transmission.

The clutch driven plates of today do not have dampers or friction elements. These functions are integrated in the dual mass flywheel.

The clutch driven plate center is greased internally when the clutch driven plate is installed at the factory. This reduces the friction between the clutch driven plate and the input shaft to make shifting easier.

When replacing the clutch driven plate, the input shaft must be lubricated.

Scheme 261

The dual mass flywheel reduces noise from the transmission and improves driveability.

The dual mass flywheel helps reduce the load on the crankshaft bearings. It also improves shift quality because the flywheel mass on the clutch driven plate is lower.

The components of the dual mass flywheel can rotate in relation to one another. This twisting depends on the load from the engine. Twisting of a dual mass flywheel is up to 60 degrees in both directions. You can feel a certain twisting between the components if you turn a dual mass flywheel.

Scheme 262

Shift cable

1. pulled when 1st, 3rd and 5th gears are selected
2. pushed when 2nd, 4th and 6th gears are engaged.

Mechanical transmission cable for lateral travel

1. pulled when the gear selector lever is moved to the position between 1st and 2nd gears
2. pushed when the gear selector lever is moved to the position below 5th and 6th. Gives maximum lateral movement when the lever is moved to back-up (reverse) gear.

There is a return spring on the lateral movement lever. The control unit in the transmission has a return spring.

The mechanical transmission cable for lateral travel is adjustable lengthwise. The adjuster is positioned on the mounting towards the lever on the transmission (1). The spring in the gear selector assembly pulls the mechanical cable and then the mechanical cable is locked by hand using the catch. When locking the gear selector lever and the components in the transmission must be in neutral position.

1st gear

Scheme 263

When 1st gear is selected, the coupling sleeve for 1st-2nd gear is moved by a gear selector fork along the synchronizing hub towards the idler wheel for 1st gear. The coupling sleeve and synchronizing hub lock the idler wheel for 1st gear at the intermediate shaft 1-2, 5-6.

Engine torque is transferred to the input shaft via the clutch. The 1st gear rack on the input shaft transfers the power to the idler wheel for 1st gear. From there power is transferred to intermediate shaft 1-2, 5-6 and to the final drive, which in turn transfers the power to the ring gear. The ring gear is connected to the drive shafts through the differential.

2nd gear

Scheme 264

When 2nd gear is selected, the coupling sleeve for 1st-2nd gear is moved by a gear selector fork along the synchronizing hub towards the idler wheel for 2nd gear. The coupling sleeve and synchronizing hub lock the idler wheel for 2nd gear at the intermediate shaft 1-2, 5-6.

Engine torque is transferred to the input shaft via the clutch. The 2nd gear rack on the input shaft transfers the power to the idler wheel for 2nd gear. From there power is transferred to intermediate shaft 1-2, 5-6 and to the final drive, which in turn transfers the power to the ring gear. The ring gear is connected to the drive shafts through the differential.

3rd gear

Scheme 265

When 3rd gear is selected, the coupling sleeve for 3rd-4th gear is moved by a gear selector fork along the synchronizing hub towards the idler wheel for 3rd gear. The coupling sleeve and synchronizing hub lock the idler wheel for 3rd gear at the intermediate shaft 3-4.

The torque of the engine is transferred via the clutch to the input shaft. The 3rd gear gearwheel on the input shaft transfers the power to the idler wheel for 3rd gear. From there power is transferred on to intermediate shaft 3-4 and to the final drive which in turn transfers the power to the ring gear. The ring gear is connected to the drive shafts through the differential.

4th gear

Scheme 266

When 4th gear is selected, the coupling sleeve for 3rd-4th gear is moved by a gear selector fork along the synchronizing hub towards the idler wheel for 4th gear. The coupling sleeve and synchronizing hub lock the idler wheel for 4th gear at the intermediate shaft 3-4.

The torque of the engine is transferred via the clutch to the input shaft. The 4th gear gearwheel on the input shaft transfers the power to the idler wheel for 4th gear. From there power is transferred on to intermediate shaft 3-4 and to the final drive which in turn transfers the power to the ring gear. The ring gear is connected to the drive shafts through the differential.

5th gear

Scheme 267

When 5th gear is selected, the coupling sleeve for 5th-6th gear is moved by a gear selector fork along the synchronizing hub towards the idler wheel for 5th gear. The coupling sleeve and synchronizing hub lock the idler wheel for 5th gear at the input shaft.

The torque of the engine is transferred via the clutch to the input shaft. The 5th-6th coupling sleeve and 5th gear idler wheel, located on the input shaft, transfer the power to the gear wheel for 5th gear. From there power is transferred on to intermediate shaft 1-2, 5-6 and to the final drive which in turn transfers the power to the ring gear. The ring gear is connected to the drive shafts through the differential.

6th gear

Scheme 268

When 6th gear is selected, the coupling sleeve for 5th-6th gear is moved by a gear selector fork along the synchronizing hub towards the idler wheel for 6th gear. The coupling sleeve and synchronizing hub lock the idler wheel for 6th gear at the input shaft.

The torque of the engine is transferred via the clutch to the input shaft. The 5th-6th coupling sleeve and 6th gear idler wheel on the input shaft transfer the power to the gear wheel for 6th gear. From there power is transferred on to intermediate shaft 1-2, 5-6 and to the final drive which in turn transfers the power to the ring gear. The ring gear is connected to the drive shafts through the differential.

Back-up (reverse) gear

Scheme 269

When back-up (reverse) gear is selected, the coupling sleeve for back-up (reverse) gear is moved by a gear selector fork along the synchronizing hub towards the idler wheel for back-up (reverse) gear.

The coupling sleeve and synchronizing hub lock the idler wheel for back-up (reverse) gear at the back-up (reverse) shaft.

The torque of the engine is transferred via the clutch to the input shaft. The 1st gear gearwheel on the input shaft transfers the power to the idler wheel for 1st gear. From there to the back-up (reverse) gear idler wheel and then to the coupling sleeve for back-up (reverse) gear. From there power is transferred on to intermediate shaft 1-2, 5-6 and to the final drive which in turn transfers the power to the ring gear. The ring gear is connected to the drive shafts through the differential.

SHIFT MECHANISM

The transfer from the control unit to the selector forks is divided between two locations in the transmission

1. The upper gear selector affects back-up (reverse) gear and 1st and 2nd gears
2. The lower gear selector affects 3rd, 4th, 5th and 6th gears.

4 gear selector forks transfer the movement from the control to the relevant coupling sleeve.

The shift lever actuates the shift forks, which are mounted in bearings in the housing.

Two carrier plates are used to transfer the torque from the longitudinal movement lever to the axially sliding gear selectors. The carriers run in a groove in the gear selector plate.

The gear selector panel is affected by a carrier plate connected to the lateral movement lever.

The carrier plates move vertically between four possible positions. The different gears can be activated in the different positions.

1. In the uppermost position the upper gear selector activates back-up (reverse) gear
2. In the next highest position the lower gear selector activates 5th and 6th gears
3. In the next lowest position the lower gear selector activates 3rd and 4th gears
4. In the lowest position the upper gear selector activates 1st and 2nd gears.

The longitudinal movement lever acts on the shift lever so that the correct gear is engaged. The control unit also contains two springs (10 and 12) that help return the shift lever to the neutral position.

The shift lever assembly houses a solenoid that serves as an electronically controlled reverse inhibitor. If vehicle speed exceeds 25 km/h (15.5 mph), the solenoid is activated and it is not possible to engage reverse gear. When speed drops below 15 km/h (9 mph), the solenoid releases and reverse gear can be engaged.

When driving straight ahead, the ring wheel and differential housing rotate at the same speed as the drive shafts and the driving wheels.

When cornering, the differential gears rotate to compensate for the different speeds of the wheels. Because the small side gears are rotating on the shaft journal, the drive shafts can rotate at different speeds. Power is transferred from the differential housing to the drive shafts via the small side gears in the same way as when driving straight ahead. Both drive wheels still have the same driven power.

Cars with four wheel drive have a splined pin on the differential housing. The sleeve on the pin connects the differential housing with the bevel gear. Torque is directed from the bevel gear to the rear wheels.

CLUTCH, GENERAL

The primary role of the clutch system is to disengage the transmission when shifting, transfer torque and to allow comfortable starting.

Disengagement of the clutch driven plate when shifting is a very important part of this functionality. When the driver presses the clutch pedal, the throwout bearing moves a given distance towards the diaphragm spring and disengages the clutch driven plate. The clutch is raised and held in position by the springs riveted to the pressure plate.

Complete disengagement takes place during the last quarter of clutch pedal travel.

The clutch driven plate is trapped between the flywheel and pressure plate to transfer the torque. The torque is transferred via the clutch to the input shaft.

The torque is transferred across the crankshaft via the flywheel to the clutch driven plate. Half of the torque is transferred via the clutch screw to the clutch housing through lifting springs, over to the pressure plate and to the clutch driven plate. The clutch driven plate then transfers the torque via its hub and splines to the input shaft.

During down-shifting the rotation speed of the clutch driven plate increases. It decreases during up-shifting. The engine speed (RPM) is then synchronized with the vehicle speed when the clutch is released. If there is no disengagement during shifting, there would be abnormal synchronization wear in the transmission.

Pre-tensioned lifting springs connect the clutch housing and the pressure plate.

The clutch is defined by the 3 characteristic curves

1. pressure plate pressure against the clutch driven plate
2. diaphragm spring pressure against the throwout bearing
3. the lift of the pressure plate.

The pressure of the pressure plate increases as the clutch driven plate wears. This increase in pressure increases the pressure at the diaphragm spring and with it pedal effort as the clutch driven plate wears. The diaphragm spring moves backwards as the clutch driven plate wears. The clutches are guaranteed to tolerate wear of 1.5 mm to the facing. This means that the clutch cover has a wear capacity of 8-9 mm to compensate for rearward movement of the throwout bearing.

HYDRAULIC CLUTCH CONTROL MECHANISM WITH CONCENTRIC SLAVE CYLINDER (CSC)

In order to change gears, the transmission must be disengaged from the engine. This is done by the clutch pedal. When the clutch pedal is pressed, fluid is transferred from the master cylinder through a pipe to the concentric slave cylinder (CSC) in the clutch cover. This then acts on the clutch, disengaging the clutch driven plate.

Sound and vibration is also transferred from the engine. The pipe and hose are balanced so that they absorb vibration.

SELF-ADJUSTING CLUTCH (SAC)

When the facing on a clutch driven plate wears, the normal working position (travel) of the pressure plate and the disengagement position increase.

On the self-adjusting clutch an adjuster ring responds to the wear of the clutch driven plate. As wear increases, the adjustment ring moves automatically slightly at the next disengagement and adjusts the bearing position of the diaphragm spring. This means that the operating travel of the pressure plate and therefore engagement pressure remain constant.

Scheme 270

The transmission is intended to be part of a transverse drive line with front wheel or four wheel drive. The transmission and final drive are constructed together in a common housing made of aluminum. The unique design of the transmission and final drive makes it extremely compact, yet capable of transferring high torque.

The engine and transmission have damped mountings, either on the side members with pendulum mounting or on a sub frame.

The gear controls consist of the gear selector assembly, electronic back-up (reverse) inhibitor and two mechanical shift cables which are connected to a lever each on the transmission. The gear selector is not adjustable. However lateral movement can be adjusted. If there is a fault or damage in/to one of the mechanical cables, both must be replaced at the same time.

The gear selector assembly is seated in rubber bushings secured to the floor of the tunnel for efficient sound insulation. The bearings for the gear selector lever in the gear selector assembly and the bearings for the outer mechanical cable controls are permanently lubricated low friction bearings.

The oil is synthetic.

Scheme 271

The transmission control module and the gear-shift position sensor form one unit. This unit is mounted on the top of the transmission housing, on the gear shift linkage rod. The control module connector is directly connected to the transmission.

The gear-shift position sensor provides the transmission control module with information about the gear selected and whether back-up gear is selected so that the back-up lamps can be lit if required. The gear-shift position sensor contains a permanent magnet and a linear Hall sensor. The gear-shift position sensor generates a signal voltage between 0 and 5 V. This signal voltage corresponds to the currently selected gear selector lever position.

There are diagnostics for the gear-shift position sensor.

Voltage level for the different gears

approx. 0.65 V

approx. 1.64 V

approx. 2.12 V

approx. 2.49 V

Scheme 272

The shift solenoids and are positioned in the valve body in the transmission control system, which is mounted on the front edge 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 and grounded in the control system. The shift solenoids control shifting. The transmission control module determines which gear is to be used by activating them in different patterns.

There is a diagnostic for the shift solenoids.

Scheme 273

The lock-up-solenoid, is located in the gearbox control system, which is mounted on the front edge of the gearbox.

The lock-up-solenoid, consists of an electric coil that controls a hydraulic valve. The solenoid is controlled, like all linear solenoids in the gearbox, by a pulsed current with a frequency of 300Hz and grounded via the Transmission Control Module. The average value on the current signal that deploys the solenoid varies between 0.1 A and 1 A and the demand controls the deployment.

The solenoid controls the torque converter's Lock-up engagement. Engagement occurs by the solenoid pulsing, which gives a smooth engagement of the lock-up function. The solenoid allows the torque converter to work in one of three positions: "Open", "Controlled slipping" and "Locked".

The hydraulic function of the solenoid is linear.

There are diagnostics for the solenoid.

Scheme 274

The line pressure solenoid, is in the transmission control system, which is mounted on the front edge of 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. The solenoid is grounded via the transmission control module (TCM). The hydraulic 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 currents) the line pressure is low. During low pulse conditions the line pressure is high. In the event of an open-circuit the line pressure reaches maximum which causes hard shifting. The hydraulic valve is then completely open.

There are diagnostics for the solenoid.

Scheme 275

The line pressure solenoid, is in the transmission control system, which is mounted on the front edge of 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. The solenoid is grounded via the transmission control module (TCM). The hydraulic 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 currents (approximately 1 A)) 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 causes hard shifting. The hydraulic valve is then completely open.

There are diagnostics for the solenoid.

Scheme 276

The transmission input speed sensor (input shaft speed) is on the upper side of the transmission housing. The sensor is an active sensor and is supplied with 12 V. When the pulse wheel on clutch C1 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 transmission control module (TCM) uses information about the input shaft speed to calculate the torque reduction to be requested from the engine control module (ECM) when shifting. The value is also used to compare the engine speed (RPM) with the speed of the input shaft in order to calculate the slipping rate of the torque converter. The value is also compared with the transmission output speed sensor signal in order to calculate the actual gear ratio. This is done to check whether the value corresponds to the expected gear ratio.

There are diagnostics for the transmission input speed sensor.

Scheme 277

The transmission output speed sensor (speed of the output shaft) is on the reverse of the transmission housing. The sensor provides signals to the transmission control module (TCM) about the vehicle speed. The output shaft speed sensor is an active sensor and is supplied with 12 V. When the pulse wheel (wheel for shift-lock) 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 and is also used for diagnostics.

There are diagnostics for the transmission output speed sensor.

Scheme 278

The temperature sensor is an NTC sensor. The temperature sensor is on the transmission control system inside the side cover. It gauges the temperature of the transmission fluid in the oil pan. The temperature sensor is integrated in the cable harness. 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 279

The gear selector assembly is in the tunnel console. It is mechanically connected to the transmission by a cable which moves the gear valve in the transmission control system. The gear selector module (GSM) is on the top panel of the gear selector assembly. The gear selector module (GSM) is powered by the transmission control module (TCM). The gear selector module (GSM) uses serial communication to communicate with the transmission control module (TCM) to light the gear position indicator for example. The gear selected is indicated by a row of LEDs in the top panel on the gear selector assembly.

There is a directly connected cable from the transmission control module (TCM) to the gear selector module (GSM) which controls the shift-lock solenoid. The power supply and ground for the shift-lock solenoid are directly connected to the gear selector module (GSM).

The switch for winter mode (W) is located in the lever carrier's top panel (switch and function are discontinued from model year 2008). At activation, the switch sends a request to activate winter mode to Transmission control module (TCM) (TCM). Transmission control module then decides if winter mode is possible or not.

There are diagnostics for the gear selector module. In the event of a fault, a signal about the fault status is transmitted to the transmission control module where any diagnostic trouble codes are stored.

This function can be used to continuously read off the status of the control module's input and output signals.

For further information about parameters, see: DESCRIPTION OF PARAMETERS

ACTIVATING COMPONENTS

This function can be used to activate components to check that they are working.

For further information about activations, see: DESCRIPTION OF ACTIVATIONS

New software can be downloaded into the transmission control module. When ordering software, the hardware and the software in the car is compared to the information in the Volvo central database. If the comparison is OK the software is downloaded to the control module.

If the comparison between the car and Volvo central database is not OK, the database is updated with the car configuration. When this is complete the software is downloaded.

CONTROLLING THE SHIFT SOLENOIDS WHEN SHIFTING

The solenoids are activated in a specific pattern to control shifting and the lock-up function. Solenoids determine which gear is to be used. Solenoids and determine engagement by adjusting the hydraulic line pressure. The basic parameters for the different shifting points are the accelerator pedal position and the vehicle speed. The shift quality is decided by controlling the torque.

The pressurization of the clutches and the brakes is adjusted by reading the changes in speed of the transmission input shaft during the shifting process and comparing them to the values calculated in the transmission control module.

Two different shift patterns are available: normal mode and winter mode.

In normal conditions, shifting and lock-up occur at relatively low engine speeds to reduce fuel consumption. In the event of rapid accelerator pedal movements, the transmission control module automatically shifts to sport mode.

GEARSHIFT PATTERNS

GEARSHIFT PROGRAM

Economy mode

When driving at normal acceleration, the transmission control module (TCM) uses a pre-set shifting program, optimized to shift for economy driving. This shifting program is suitable for "normal" driving which provides earlier up shifts and lock-up. In addition the transmission oil pressure is adjusted to provide smooth gear engagement.

Sport mode

The transmission switches from economy mode to sport mode if the accelerator pedal (AP) is pressed down quickly. The conditions are that the throttle opens and the vehicle speed exceeds 50 km/h. As soon as the accelerator pedal (AP) is moved less quickly economy mode is resumed. In the sport mode shifting program the shifting points are adjusted to provide the best possible performance. Down shifting occurs at lower engine speed (RPM).

Extreme mode

At wide open throttle (WOT) the kick-down function is engaged and the transmission shifts to the lowest possible gear. In this way a boost of power is achieved when overtaking for example.

Winter mode

Winter mode is selected using the button on the top panel of the gear selector assembly. Winter mode enables starting off in a high gear to prevent the wheels from spinning on a slippery surface. This mode can also be used in other difficult situations in which the driver needs more direct control over gear selection. When D is selected, the car starts in 3rd gear. There is automatic shifting between 3rd, 4th and 5th gears.

When winter mode is selected a lights on the dashboard.

If kick-down is activated in Winter mode, the transmission uses all gears for maximum performance.

OTHER MODES

Adaptation

The transmission control module monitors each shift during all driving conditions to fulfill consistent and smooth shifting. This is carried out by the control module either lowering or increasing the hydraulic line pressure used during the shift itself. The changed pressure levels are stored in the control module memory when the car has been switched off and are retrieved on start-up. This provides improved shifting comfort and increased service life.

Complete adaptation occurs when the following conditions have been met

1. throttle opening is steady
2. oil temperature between 65 °C and 110 °C.

Temperature controlled lock-up

If the transmission temperature increases abnormally as a result of heavy load under high ambient temperature conditions, the torque converter lock-up function is activated as often as possible. This reduces slippage and the generation of heat in the transmission. The lock-up function will not be used if the temperature drops below +20 °C.

Slipping lock-up

This function ensures smoother engagement with reduced vibration and decreased noise when a gear is engaged. In this mode, the torque converter clutch is engaged, but not fully locked.

The following conditions must be met in order for the function to activate

1. the gear selector in position or
2. gear 3, 4 or 5
3. the transmission input speed is 1100 RPM or more and the throttle opening is 20 - 35% depending on the engine version
4. the transmission oil temperature is 40 - 120 °C.

Due to the torque converter slipping between 50-200 RPM, the friction properties of the transmission fluid are very important. The transmission fluid differs from conventional ATF oil properties. Always use the specified fluid for this transmission. Failure to do so may compromise the function and set a diagnostic trouble code (DTC).

The engine coolant must reach a certain temperature before the function engages.

Driving uphill

The Transmission Control Module can change the gearshift pattern slightly when driving uphill. This is to avoid close gearshifts.

Alternative driving programs

There are driving programs that are implemented in the transmission but that only are active on certain variants.

Kick-down

When the accelerator pedal is pressed down past a certain point, the Kickdown function is activated. This means that downshifting takes place to get faster acceleration. The pedal position for Kickdown is designated as 110%.

Quick step

Quick step makes the gearshifting function sportier when the driver is more aggressive on the pedal. Lower gears are used for better acceleration.

Fast Off

Fast Off is used to reduce the number of shifts due to heavy traffic in, e. g., city traffic.

The function is activated at fast releases of the accelerator pedal. Even the vehicle's speed, brake pedal, and curve detection affect its function. By keeping a lower gear than normally, unnecessary shifts are avoided. For aborted passing, a lower gear is maintained to be able to take the initiative for future passing.

Scheme 280

When the gear selector is moved to the Geartronic position the automatic transmission remains in hydraulic position. When the gear selector is moved upwards (+) the gear selector module (GSM) transmits a signal to the transmission control module (TCM) to shift up. When the gear selector is moved downwards (-), a signal is transmitted to the transmission control module (TCM) to shift down. The driver information module (DIM) switches the symbol in the combined instrument panel from D to the current gear, for example 3, when the gear selector is in M mode. The transmission control module (TCM) transmits a signal to the gear selector module to light the M LED and switch off the other LEDs. The transmission control module determines if the shift can take place. If shifting is permitted the solenoids are activated according to each specific gear pattern.

However, in certain situations the transmission control module takes over responsibility for determining shifting. The follow applies

1. When stationary only 1st, 2nd and 3rd gears can be selected. 4th gear can be selected at speeds in excess 30 km/h and 5th at speeds in excess of 40 km/h
2. The kick down function is only available in the position.
3. Automatic down shifting occurs for all gears below a certain speed. Example: 2nd gear is selected. Automatic down shifting occurs when shifting from 2nd gear to 1st at 2 km/h if the speed, before this, has exceeded 25 km/h. Otherwise 2nd gear is maintained. For example, there may be situations when 2nd or 3rd gear is engaged despite the car being stationary. Manual up shifting is required after automatic down shifting
4. The permitted engine speeds for manual down shifting corresponds to those for kick-down up shifting, i. e. engine speeds of approximately 6, 000 RPM
5. If transmission temperature becomes too high then the Transmission Control Module takes over the gearshift decisions. The purpose of this is to engage a gear where lock-up is possible at the current speed.
6. Lock-up is possible in 3rd, 4th and 5th gears..

Other

In position M, the signal indicating the position of the lever to the gear selector module is generated as follows: For each of the three gear selector positions there is a Hall sensor on the printed circuit board for the gear selector control module. A permanent magnet on the cover in the gear selector lever affects the output signals from the sensors to the control module. The control module can read off the position of the lever through the differences in the signal characteristics.

Scheme 281

To avoid any chance of the gear selector inadvertently moving from the or position, the car is also equipped with an electrically operated shift-lock function. This locks the interlock pin in the gear selector lever in the shift-lock section, locking the selector lever in the - or position.

From to another gear position

To move the gear selector from the position, the ignition must be switched on and the brake pedal depressed.. The transmission control module retrieves the brake pedal position via the CAN network and the currently selected gear from the internal gear-shift position sensor. The signal is then transmitted from the transmission control module to the gear selector module to control the solenoid in the gear selector assembly. When the gear selector is in position, the solenoid is activated and the lock pin slides in. The gear selector lock button can be pressed down as usual to select another gear. There is a Hall sensor in the gear selector assembly which is affected by a permanent magnet on the cover of the assembly. The Hall sensor is deactivated when the gear selector is moved from position. The shift-lock solenoid is disengaged at the same time. This prevents the gear selector from sticking in position N. When the ignition is in position "I" or "0" the solenoid is deactivated. The gear selector is mechanically locked in position by breaking the power supply to the solenoid.

From to another gear position

To move the gear selector from the position, the ignition must be switched on and the brake pedal depressed.. The transmission control module retrieves the brake pedal position via the CAN network and the currently selected gear from the internal gear-shift position sensor. The signal is then transmitted from the transmission control module to the gear selector module to control the solenoid in the gear selector assembly.

With the gear selector in the solenoid deactivates and the lock pin is drawn in and the gear selector can be shifted to position and normally. However the lock button on the gear selector must be pressed before or can be selected. When the ignition is in position "I" or "0", the solenoid is deactivated.

Shift-lock override

The mechanical lock mechanism in the gear selector assembly can be overridden so that the gear selector can be moved when the power is off or in the event of an electrical fault. A small tool can be inserted under a cover on the gear selector assembly panel to release the gear selector.

PARK / NEUTRAL POSITION (PNP) FUNCTION

The car has a park/neutral position function to prevent the starter motor from turning when a gear is selected. This function is controlled by the transmission control module, which receives a signal from the gear selector module indicating that the gear selector is in position or. The park / neutral position function ensures that the starter motor can only be activated when the gear selector is in position - or. This prevents the car from lurching forwards when started.

ADAPTATION DATA

There are two functions for adaptation in the transmission control module (TCM) software which can be activated

1. Resetting adaptation - should be performed after replacing an internal component or the whole transmission. the transmission control system the transmission fluid the entire transmission transmission control module (TCM).
2. Adaptation function - This function helps the mechanic to adapt the transmission. This makes it easier to reset the function of the transmission after repair or replacement of, for example: the transmission control system the transmission fluid the entire transmission transmission control module (TCM).

When the adaptation function has been activated, the test drive instructions must be followed. The following shifts can be adapted

1. 1-2
2. 2-3
3. 3-4
4. 4-5
5. N-D
6. 5-4
7. 4-3
8. 3-2
9. 2-1
10. N-R.

While the function is activated, the general warning lamp in the combined instrument panel indicates when each shift has been adapted to its target value.

When the general warning lamp (triangle) flashes after each shift, the adaptation is complete.

Adaptation of the transmission is activated via the VIDA (Volvo scan tool) socket.

Scheme 282

A counter for transmission oil quality is built into the software for the transmission control module (TCM). The counter counts up the amount of time the oil is above a certain temperature. When the counter has reached the maximum value, the diagnostic trouble code (DTC) for an oil change is stored in the control module. When replacing transmission fluid, the counter must be reset to prevent a diagnostic trouble code (DTC) being stored incorrectly. This applies when the transmission fluid is changed and when the fluid is changed during a repair.

The reset function is activated via the VIDA (Volvo scan tool) socket.

EMERGENCY MODE IN THE EVENT OF A FAULT

An emergency program is activated to deal with the fault when the transmission control module (TCM) detects a transmission fault (permanent fault). The transmission control module (TCM) then implements certain corrective actions to protect the transmission, while leaving the car in the best possible drivable condition. Minor malfunctions do not activate an emergency program. There are different programs depending on the type of fault.

1. Emergency/limp-home mode
2. Failsafe action (temporary action)

The failsafe action is indicated as soon as the fault is detected. Normal function is resumed if the fault disappears. Emergency mode is activated for minor faults and the Limp home mode for the most serious faults. If the malfunction is intermittent, the transmission control module (TCM) returns to normal operation the next time the ignition is switched on.

The warning lamp in the combined instrument panel lights and a text message appears in the display in the combined instrument panel if emergency/limp home mode is engaged. No text is displayed until the fault has been detected when the ignition is switched on.

Scheme 283

AW55-51 (and AW50AWD) is a 5-speed electronically controlled automatic transmission with a lock-up function for the three highest gears. The transmission control module (TCM) adapts the gear changes to ensure that the correct gear is selected for the driving mode, engine load, driver requirements, speed etc. This gives good fuel economy combined with increased comfort by ensuring smoother gear changes and lower noise levels.

The transmission control module (TCM) receives information about the desired gear position and driving mode from the driver. In conjunction with the signals from a number of sensors in the transmission and the engine control system, unlike with a purely hydraulically controlled transmission, this allows the control module to calculate the optimal shifting points and engagement of lock-up. The control module allows for small changes in the operating conditions and adapts the various transmission functions to ensure that the correct gear is always selected in relation to the driving mode selected by the driver.

The transmission control module (TCM) has adaptive capability. This is to ensure smooth shifting throughout the service life of the transmission.

In order to precisely determine the gear shift and lock-up engagement points based on the driving mode selected, the control module receives information about the following

1. Selected gear position - from the gear-shift position sensor
2. Selected driving mode economy/sport - reactive function programmed in the control module which is controlled by the speed at which the accelerator pedal (AP) is depressed. Quick "pedal movement" = sport mode. Winter (W) mode is activated using a switch on the gear selector assembly
3. Transmission input shaft RPM - from the transmission speed sensor
4. The transmission output shaft RPM - from the transmission output speed sensor
5. Transmission fluid temperature - from the temperature sensor in the transmission
6. The engine speed (RPM) and torque as well as throttle opening - from the engine control module (ECM) via the controller area network (CAN)
7. If the accelerator pedal (AP) is depressed and to what extent - from the engine control module (ECM) via the controller area network (CAN)
8. The engine coolant temperature - from the engine control module via the controller area network
9. Vehicle speed - from the brake control module via the controller area network
10. If the brake pedal is depressed and to what extent - from the brake control module via the controller area network.

Scheme 284

The following components are included in the control system for automatic transmissions

1. Transmission control module - Controls activation and deactivation of the solenoids by processing the signals from components such as the transmission input and output speed sensors and the temperature sensor. Also stores adaptive data as well as diagnostic trouble codes and frozen values for diagnostics
2. Shift solenoid, - Controls shifting in the transmission.
3. Shift solenoid, - Controls shifting in the transmission.
4. Shift solenoid, - Controls shifting in the transmission.
5. Shift solenoid, - Controls shifting in the transmission.
6. Shift solenoid, - Controls shifting in the transmission.
7. Lock-up solenoid, - Controls the lock-up function and is also used for certain shifts.
8. Line pressure solenoid, - Controls the line pressure in the transmission.
9. Line pressure solenoid, - Controls the transmission shifting pressure and is also used for certain shifts.
10. Transmission input speed sensor (input shaft speed) (1) - Provides the transmission control module (TCM) with information about the input shaft speed from the engine
11. Speed sensor (output shaft speed) (2) - Provides the transmission control module (TCM) with information about the output shaft speed from the transmission
12. Oil temperature sensor (3) - Provides the transmission control module (TCM) with information about the oil temperature of the transmission
13. Gear-shift position sensor, built-in to the transmission control module (TCM) (4) - Provides the transmission control module (TCM) with information about the selected gear
14. Gear selector module (GSM) - Provides the transmission control module (TCM) with information about the Geartronic mode and winter mode (W).

The table below summarizes the input signals to and output signals from the transmission control module (TCM). The signal types are divided into directly connected signals, serial communication and controller area network (CAN) communication. The illustration below (Scheme 285) displays the same information with the Volvo component designations.

Scheme 285

WASHER SYSTEM, GENERAL

Note. As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information in the illustrations is always correct.

Scheme 286

Note. The illustration shows the basic appearance of the Washer system, 4 cylinder engines and the Washer system, 5 cylinder engines.

1. Washer can, or two washer cans
2. Dual pump or Monopump
3. High pressure pump
4. Level sensor.

The washer system consists of

1. Washer can (1) (one or two depending on washer system)
2. Dual pump (2) for windshield washing and rear window washing (3 and 5-door models); Monopump for windshield washing (2 and 4-door models)
3. High pressure pump (3) (vehicles with headlamp washing)
4. Level sensor (4)
5. Hoses and nozzles for headlamps, windshield and rear windshield.

There are two different washer systems, depending on the engine variant. The washer cans have a different design and volume

1. 4 cylinder engines have two washer cans holding a total of 4.1 liters
2. 5 cylinder engines have one washer can holding a total of 6.3 liters.

For further information concerning the washer systems, see WASHER SYSTEM, 4 CYLINDER ENGINES or WASHER SYSTEM, 5 CYLINDER ENGINES .

The pumps and the level sensor are located on the lower section of the washer can.

The pumps are mounted in the washer can using rubber bushings. The filters are integrated in these rubber bushings.

Scheme 287

1. Washer nozzle windshield washing with check valve
2. Hose windshield washing
3. Headlamp wash / wipe with nozzle
4. Hoses headlamp washing
5. Hoses rear windshield washing and nozzle
6. Washer can
7. Filling tube with cover
8. Washer can

The washer system comes in two versions - one for 3 and 5-door models and one for 2 and 4-door models.

Both variants can be ordered with or without headlamp wash / wipe. Vehicles with headlamp wash / wipe have a high pressure pump located on the outside of the washer can (6).

Because 3 and 5-door models have rear window washing, they have a dual pump located on the washer reservoir instead of the standard monopump.

Scheme 288

1. Washer nozzle windshield washing with check valve
2. Hoses windshield washing
3. Washer can
4. Filling tube with cover
5. Hoses headlamp washing
6. Headlamp wash / wipe with nozzle
7. Hoses rear windshield washing and nozzle

The washer system comes in two versions - one for 3 and 5-door models and one for 2 and 4-door models.

Both variants can be ordered with or without headlamp wash / wipe. Vehicles with headlamp wash / wipe have a high pressure pump located on the outside of the washer can (3).

Because 3 and 5-door models have rear window washing, they have a dual pump located on the washer reservoir instead of the standard monopump.

WASHER SYSTEM

Washer nozzle

There are also washer nozzles on the hood and bumper cover for cleaning the windshield and headlamps.

The check valve in the windshield washer nozzle prevents windshield washer fluid from flowing back into the system.

Vehicles with three or five doors also have a jet to clean the rear window.

Washer pump

There are two different types of washer pump.

The monopump is used for washing the windshield (2 and 4-door models).

The dual pump is used for washing both the windshield and the rear windshield (3 and 5-door models). The pump is double acting. The dual pump changes direction when rear windshield washing is activated, washing though the rear windshield washing outlet.

High pressure pump

The high pressure pump is used for headlamp wash / wipe.

Level sensor

The central electronic module (CEM) monitors the washer fluid level in the washer can using the level sensor. The switch in the level sensor gives a signal when the level is below 0.7 liters. A text message indicating that it is necessary to fill with washer fluid is displayed in the driver information module (DIM).

The headlamp washers are not activated if the level in the washer can is lower than 0.7 liters.