Miscellaneous Electrical - Design and Function: Overview Volvo XC90 I

Scheme 47

A timer control function can be connected to the electrical parking heater which is controlled via the accessory electronic module (AEM).

The system consists of

1. A relay for the electrical parking heater
2. Wiring between the relay and accessory electronic module (AEM).

The relay is mounted on the engine block heater and controls the electrical parking heater and relay passenger compartment socket.

The relay acts as a switch and is supplied with power and controlled via the wiring from the accessory electronic module (AEM).

The relay is connected to the ground terminal in the engine compartment.

When post-installing the timer start system for the electrical parking heater the car must be configured using new software which is carried out via VIDA (Volvo scan tool).

There are diagnostics for the relay/control signal.

GENERAL INFORMATION

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

READING OFF THE CONTROL MODULE IDENTIFICATION

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

The codes contain information about the control module

1. hardware P/N (control module without software)
2. hardware serial number (control module without software)
3. software P/N
4. diagnostic software P/N
5. start address CAN configuration.

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

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

The codes contain information about the control module

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

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

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

The codes contain information about the control module

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

DESCRIPTION OF PARAMETERS

This parameter description contain both a description for Differential Electronic Module (DEM) generation 3 and for generation 4. Generation 3 is presented first, and then generation 4.

The control module can be identified by reading off a code from the control module memory.

The code contains information about the control module's

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

DESCRIPTION OF FUNCTION OF THE OPERATING STATUS OF THE HEATER

The heater can have a number of different statuses. Each status and what should occur in it is described below.

The rear electronic module (REM) is the main unit for the alarm function and contains diagnostics for the alarm function.

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

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

The codes contain information about the control module

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

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

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

The codes contain information about the control module

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

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

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

The codes contain information about the control module

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

New software can be downloaded into the audio module (AUD). When software is ordered the software and hardware of the vehicle are compared with Volvo's central database. If the comparison corresponds then the software is downloaded into 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 control module has a built-in diagnostic system, Volvo Diagnostic, which continuously monitors internal functions as well as input and output signals.

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

The codes contain information about the control module

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

Software can be downloaded to the Bluetooth phone module (BPM). 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 vehicle and the Volvo central database does not correspond, the database is updated with the vehicle configuration, and then the software and any security codes (Security access code) is downloaded.

Scheme 48

The system is a handsfree system which allows the customer to control their own cellphone from the vehicle and allows the customer to use the vehicle audio system during calls.

The following telephone functions are available via the vehicle's buttons and display when a cellphone is connected to the bluetooth phone module (BPM) via bluetooth

1. Receive incoming calls with number presentation
2. End telephone calls
3. Initiate telephone calls via normal number dialing
4. Searching and initiating telephone calls from the mobile telephone's phone book. In vehicles with model year from and incl. 2012 the Bluetooth phone module (BPM) is equipped with PBAP - Phone Book Access Profile. PBAP is a new standard for faster transfer of the phone book from the customer's mobile telephone to Bluetooth phone module (BPM).
5. Accessing last number dialed/received/missed calls on the cellphone
6. Activating voice activated function in the cellphone
7. Transfer of sound between the vehicle's audio system and the cellphone can occur without interrupting the call.
8. A2DP - Advanced Audio Distribution Profile. With A2DP the customer can play back music from their mobile telephone in the car's loudspeakers via Bluetooth phone module (BPM). For vehicles with model year from and incl. 2012.

The Bluetooth phone module (BPM) (16/147) has no keypad of its own for menu management but is either controlled via the keypad on the Climate control module (CCM) (3/112) or via the steering wheel buttons. Climate control module (CCM) transmits the signals for menu management to the infotainment control module (ICM) (3/281) via the CAN network. The infotainment control module (ICM) then transmits the signals onward to the Bluetooth phone module (BPM) via the MOST network.

When using the menu via the steering wheel buttons, information is transmitted from the steering wheel module (SWM) (3/254) to the infotainment control module (ICM) via LIN communication. The information is then transmitted to the Bluetooth phone module (BPM) via the MOST network.

Menu management is displayed for the user in the display for the infotainment control module (ICM). Information is transmitted from the Bluetooth phone module (BPM) to the infotainment control module (ICM) via the MOST network.

When starting the Bluetooth phone module (BPM), receiving incoming calls or when using the phone, a request to use the display will be transmitted to the infotainment control module (ICM).

During conversations via handsfree the microphone and speakers which are connected to the Audio module (AUD) (16/105) and Integrated Audio Module (IAM) (16/1) are used. Bluetooth phone module (BPM) transmits a request to the Infotainment control module (ICM) to receive access to the speakers and microphone. The infotainment control module (ICM) transmits the request onward to the Audio module (AUD) and Integrated Audio Module (IAM). The communication between the Bluetooth phone module (BPM), infotainment control module (ICM), Audio module (AUD) and Integrated Audio Module (IAM) occurs via the MOST network.

OVERVIEW

See OVERVIEW .

The engine control module (ECM) checks itself and all input and output signals.

SYSTEM OVERVIEW

see SYSTEM OVERVIEW

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

The codes contain the following information about the control module

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

Scheme 49

While driving, the brake control module (BCM) (1) registers the acceleration and deceleration of the wheels. The 4 wheel sensors (3) (one on each wheel) give the brake control module (BCM) information about the rotation speed of the wheels. The brake control module (BCM) calculates the speed of the car using this information and puts it out on the Control area network (CAN). There the signal is accessible for other systems.

During braking, the brake control module (BCM) receives a signal from the stop (brake) lamp switch (2) indicating braking. The brake control module (BCM) then goes into standby mode for ABS control. The signal from the stop (brake) lamp switch is not required for ABS control, but does give softer control at the beginning of ABS control.

If the brake control module (BCM) detects that there is a risk of wheel lock-up, the ABS hydraulic modulator (4) is affected and the hydraulic pressure for the relevant wheel is adapted so that wheel lock up is avoided.

The pressure in the circuit is controlled so that the maximum possible braking force is transferred to the road surface. This occurs when the wheel rotates with 12-20% slippage on the surface.

ABS is first activated when the speed of the car exceeds approximately 7 km/h, which means that at speeds below approximately 7 km/h the wheels can lock up. This has little practical effect on the function of the system or from the driver's point of view.

ABS control can be divided into three stages

1. Open position. (Pressure increase). This is the normal condition during braking. The inlet valve is open and the outlet valve is closed. This permits the brake pressure to pass from the master cylinder to the wheel
2. Pressure retention phase. (Constant pressure). If the brake control module (BCM) detects that one of the wheels is rotating too slowly, the brake control module (BCM) will close the inlet valve. This stops the brake pressure to the wheel from increasing, even if the driver increases the pressure on the brake pedal. If the rotation speed of the wheel continues to fall the control moves into the pressure reduction phase
3. Pressure reduction phase. (Pressure release). The inlet valve remains closed. The brake control module (BCM) opens the outlet valve and starts the pump which transfers brake fluid from the wheel, this reduces the brake pressure. When the rotation speed has increased sufficiently the control module closes the exhaust valve, opens the inlet valve and control returns to the open position.

Steps 1, 2 or 3 are repeated until braking finishes or the ABS system stops.

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

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

The codes contain information about the control module

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

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

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

The codes contain information about the control module

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

The heater can have a number of different statuses. Each status and what should occur in it is described below.

The vehicle configuration can be read off to check what functions the car is equipped with. The following affect the function of the heater

1. Parking and additional heater function
2. Parking heater or not (gasoline engines)
3. Residual heater or not
4. Electrical engine block heater (time controlled via the driver information module (DIM)) or not.

Scheme 50

The driver sets the desired departure time using one of the two timer functions in the display on the driver information module (DIM) (5/1). The time is programmed by twisting the ring on the control stalk and by pressing the "reset" button for the desired time (timer 1, timer 2 or direct start). Direct start can also be used to start the heater.

The central electronic module (CEM) (4/56) receives data about when the driver wants to drive from the control stalk module (steering wheel module (SWM)) (3/254) and the driver information module (DIM).

The central electronic module (CEM) calculates when the heater needs to start so that it is warm enough in relation to the outside temperature. Information about temperature is obtained from the outside temperature sensor in the right-hand door mirror. This sensor is connected to the driver door module (DDM) or passenger door module (PDM).

The central electronic module (CEM) calculates when the heater needs to start

1. The heater calculates when start is required (15-50 minutes before the intended departure at medium low temperatures between -10 °C and +15 °C)
2. This procedure takes a maximum of one minute. 60 minutes at temperatures below -10 °C
3. This running time of the heater is a minimum of 15 minutes before the planned departure. (Warm temperatures between +15 °C and +25 °C).

When the heater is started directly using the control stalk it runs until it is shut off or for a maximum of 60 minutes. The heater is on for 10 minutes after the set time to allow for the driver getting to the car late.

A text message is displayed in the driver information module (DIM) when the heater is running.

Remote start of parking heater (Applies from and incl. structure week 201020)

With remote start of parking heater it is possible to set timers for the parking heater as well as direct start of the parking heater via a computer with internet connection or via mobile telephone. Only applies to vehicles with Phone module (PHM).

Scheme 51

The desired departure time is set using the steering wheel module (SWM) (3/254).

The central electronic module (CEM) (4/56) calculates when the heater needs to start. The heater starts 2 hours and 45 minutes before the set departure time, irrespective of the temperature. A text message is displayed in the driver information module (DIM) (5/1) when the electrical heater is running.

The accessory electronic module (AEM) (4/78) electrically controls when the heater should be switched on and off. The engine block heater must be connected to a wall socket. The accessory electronic module (AEM) activates a relay which closes the switch for a heater element.

Scheme 52

This function can be ordered as an accessory.

The function is activated in the driver information module (DIM) (5/1) using the control stalk (compare to the parking heater). Information about activation is sent to the central electronic module (CEM) (4/56) and climate control module (CCM) (3/112). The blower fan and damper settings are set by the climate control module (CCM). The central electronic module (CEM) transmits data to the combustion preheater module (CPM) (4/7) instructing it to activate the water pump.

When the residual heater is activated it will operate as long as the coolant temperature is above 30 °C or for a maximum of 20 minutes or until the function is switched off.

This function is used when the coolant is already warm. The coolant pump is started thereby circulating the coolant. The heat is distributed from the coolant to the passenger compartment unit in the climate control unit and on to the passenger compartment.

When the residual heater is running, the passenger compartment is heated by the climate control module (CCM) controlling the fan and damper according to a customer parameter (Applies only to electronic climate control (ECC)). This parameter is used to set the distribution between the defroster and the floor. The normal setting is 30% defroster and 70% floor.

Scheme 53

Cars with an accessory electronic module (AEM) (4/78) can have a remote start function for the heater. This allows the heater to be started using a pager. A stop or start signal is transmitted from the accessory electronic module (AEM) to the central electronic module (CEM) (4/56) to start or stop the heater (4/7). This function is available for both fuel driven and electrical heaters.

Scheme 54

The cameras take 30 images a second and compare each image with the previous one to check whether any changes have taken place. To be able to determine whether a change is of any significance when moving sideways, the camera module also has to know the vehicle's speed. To calculate the vehicle's speed and know whether the vehicle is turning, the speed signals for the respective rear wheels from the brake control module (BCM) are used. The central electronic module (CEM) (4/56) receives information from the brake control module (BCM) (4/16) via the CAN network on the respective speeds of the two rear wheels. These two signals are then passed on to the left camera module (LCM) and right camera module (RCM) respectively via serial communication.

If the camera module discovers that there is something in the dead angle, an orange LED, located on the inside of the panel at the front of the window on the door, comes on. This LED is directly connected to the respective camera module.

The blind spot information system (BLIS) can be deactivated using one of the switches on the dashboard environment panel. When this switch is depressed, a signal is transmitted from the climate control module (CCM) to the central electronic module (CEM) via the CAN network. The system is then deactivated until the switch is depressed again or the next time the vehicle is started.

If a fault is detected by the central electronic module (CEM), a diagnostic trouble code (DTC) is stored and a signal is transmitted via the CAN network to the driver information module (DIM), which turns on a general warning lamp and displays a text message.

Scheme 55

The role of the central electronic module (CEM) is to control the controller area network (CAN) and to act as a bridge between the low and high speed sections of the controller area network (CAN) and the data link connector (DLC).

It also manages the following functions

1. Alarm (certain functions)
2. Locks (certain functions)
3. Immobilizer
4. Headlamps
5. Front parking lamps
6. Front fog lamps
7. Headlamp range adjustment (certain markets)
8. Automatic range adjustment (Bi-Xenon)
9. Turn signal lamps
10. Courtesy lighting / key lighting / glove compartment lighting
11. Fuel pump
12. Wiper / washers for the windshield and headlamps
13. Starter motor
14. Speed sensitive power steering
15. Horn
16. Clock
17. Power supply (generator control)
18. Current limiting
19. Fuel level display
20. Additional heater.
21. Parking heater
22. Blind spot information system (BLIS)

The control module is to the left of the steering column under the dashboard. The entire control module is removed from the car during replacement.

A car configuration file is stored in the central electronic module (CEM). This file contains information about

1. the VIN of the car
2. the structure week
3. the equipment level of the car.

When replacing the central electronic module (CEM), the VIN cannot be read off until the software has been downloaded from the Volvo central database.

The central electronic module (CEM) communicates with directly connected components and with other control modules and components via serial communication and the control area network (CAN).

The central electronic module (CEM) uses built in diagnostics to check all activations and the input and output signals. A diagnostic trouble code (DTC) is stored if the control module detects a fault. In certain cases, the incorrect signal is replaced with a substitute value. Other control modules use the network to report to the central electronic module (CEM) if they have diagnostic trouble codes (DTCs) stored. This function is used when reading off diagnostic trouble codes (DTCs) without VIDA (Volvo scan tool).

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

The easiest way to check if the central electronic module (CEM) is grounded and receiving power is to activate the hazard warning signal flasher. The central electronic module (CEM) is powered if the function operates.

The control modules have a built-in diagnostic system, Volvo Diagnostics, which continuously monitors internal functions as well as input and output signals. The central locking system is a distributed system which stores diagnostic trouble codes (DTCs) in different control modules depending on where the fault occurred.

The lock function which is activated on delivery depends on the market. The central locking system can be configured for standard locking function or 2 stage locking function. For the standard locking function the central locking system can also include the deadlocking function.

Scheme 56

Standard locking function means that all doors and hatches are locked or unlocked simultaneously. The exception is the fuel tank filler cover which is unlocked with unlocking but locked after 10 minutes or when the vehicle reaches a speed of 16 km/h (10 mph). With locking or unlocking a confirmation is normally given via the direction indicators that the central locking has successfully performed the operation. If locking or unlocking did not succeed no confirmation is given. This confirmation also applies to the alarm functions if an alarm is installed in the vehicle.

Locking/unlocking of the vehicle can be performed with

1. the key in the driver's door lock cylinder
2. buttons on the remote control
3. the central locking switches on the inside of the front side doors.

When using the key

When locking with the key in the door lock, a hatch or a door can still be open. Doors and locks will be locked and remain locked after being closed. However, the alarm will not be activated if the vehicle has this setting (key set). This setting is made in the vehicle's configuration file which is stored in the central electronic module (CEM).

The switches on the inside of the front side doors are deactivated if the vehicle is locked with a key. To be able to lock the vehicle with the switches all doors must be closed.

When locking with the remote control

For remote control locking to be possible there must no key belonging to the vehicle in the ignition switch.

When locking, one or more doors or hatches can still be open. The alarm functions will be activated and confirmation given when the last door or hatch is closed. If the function for deadlocking is installed then this will be activated 25 seconds after the last side door is closed. The fuel tank filler cover is locked automatically after 10 minutes.

When locking with central locking switches

Locking with central locking switches can only take place if all doors are closed. If a door is open when a switch is pressed then the doors will be locked and then immediately unlocked again. The central locking switches are disconnected when the vehicle is locked from the outside, with a key or the remote control.

Normally the vehicle is unlocked by activating the remote control unlocking button. Depending on settings, this can also deactivate the alarm if installed. If the setting for alarm deactivation on key unlocking is not made then the alarm will be triggered if the vehicle is unlocked with a key. The alarm can then be reset by inserting the ignition key into the ignition switch.

The central locking system includes a number of functions. The main unit of the system is the rear electronic module (REM) (4/58). The rear electronic module (REM) communicates with the internal components both via direct connections and the CAN network.

The functions covered are

1. standard locking function
2. 2 stage locking function
3. deadlocking
4. private locking mode
5. child safety locks
6. unlocking the trunk lid/tailgate
7. unlocking the fuel tank filler cover
8. indication of the status of the doors and hatches
9. automatic locking function
10. re-locking.

After the battery has been disconnected the central locking system must be initialized. This can be performed by locking and unlocking once with the key in the driver's door or with the remote control. This is performed to ensure that the status for lock motors and doors is operative.

The locking function on the vehicle at delivery depends on the market and is stored in the vehicle's configuration file, which is stored in the central electronic module (CEM). The configuration can be read via VIDA Vehicle communication.

The air conditioning only functions at ambient temperatures above 0 °C. At temperatures lower than this, the pressure in the system is too low and the compressor is never engaged. This setting is made to prevent ice building up on the evaporator.

The air conditioning only functions when the engine is running. The air conditioning functions regardless of engine speed (RPM) and vehicle speed. The compressor is dependent on the engine speed, the higher the engine speed the more cooling that can be provided.

The blower fan must be operating before the climate control system can be engaged.

The air conditioning system has only two positions, off and on. If it is too cold in the passenger compartment, the temperature can be controlled with the normal heat and blower fan controls.

Air conditioning is based on the same principle as that used in refrigerators.

The rear climate control unit in the seven seat XC90 supplies the passengers in the third row of seats with cooled air. For the rear climate control system to function the rear climate control system blower fan motor must be running and the front climate control system must be switched on.