Electronics - Design and Function - 1 of 4: Overview Volvo C70 II

Scheme 312

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. cable harness between the relay and the 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 vehicle must be configured using new software which is carried out via VIDA (Volvo scan tool).

There are diagnostics for the relay/control signal.

READING OFF THE CONTROL MODULE IDENTIFICATION

VIDA (Volvo scan 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 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 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.

SYSTEM OVERVIEW

Alcohol Analyzing Start Inhibitor is an option on the S60/V60/S80/V70/XC60/XC70 from model year 2008 and on the C30/C70/S40/V50 from model year 2009. The Alcohol Analyzing Start Inhibitor is not found in vehicles with keyless entry.

The following are included in the Alcohol Analyzing Start Inhibitor system

1. Central electronic module (CEM)
2. Driver information module (DIM)
3. Remote Receiver Module (RRX)

VIDA (Volvo scan 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 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 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 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 can be identified by means of reading off a number of codes.

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 313

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) provide the brake control module (BCM) with information about the rotation speed of the wheels. The brake control module (BCM) uses this information to calculate the vehicle speed. The control module transmits the signal on the controller area network (CAN) where it can be accessed by other systems.

During braking, the brake control module (BCM) receives a CAN signal from the engine control module (ECM) and stop lamp switch (2) indicating braking. The brake control module (BCM) then goes into standby mode for ABS control. The signal from the stop 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, which means that the wheel rotates with 12-20% less slippage on the surface.

ABS is first activated when the speed of the car exceeds approximately 7 km/h. This 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 maintenance phase . 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 release phase . The inlet valve remains closed. The brake control module (BCM) opens the outlet valve and starts the pump. This transfers brake fluid from the wheel, reducing the brake pressure. When the rotation speed has increased sufficiently the control module closes the outlet 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 brake energy regeneration system enables the use of kinetic energy in a more efficient way. When the driver brakes the vehicle or releases the accelerator pedal and the vehicle is engine braked, the vehicle's kinetic energy is recycled and stored in the vehicle's battery. An alternator converts the vehicle's kinetic energy, via the driveline, into electricity, which charges the battery more under those conditions (when it is free). When the driver depresses the accelerator again, the alternator charges the battery less than normal or not at all. The vehicle then receives the energy that was previously stored in the battery back again.

As the alternator charges less, less force is required to rotate the alternator, which reduces the load on the engine, which reduces the energy demand and which thereby can also reduce fuel consumption. Fuel consumption can be reduced by approx. 1-3 %.

In vehicles with normal conventional battery charging, the system always strives to charge the battery to a 100% charge level (State of Charge (SoC)). When the battery is fully charged, it cannot take any more energy. In order for the battery to take more energy, during engine braking for example, the battery cannot already be fully charged. The charging system therefore strives to retain the battery at a SoC of about 80 %. This makes it possible to charge the battery with energy and reuse the energy from the battery.

In order for the battery to be sufficiently receptive to charging for this function, the battery's temperature must be between + 5 °C - + 55 °C. At temperatures below, respectively, above this interval, brake energy regeneration is not permitted and the system will then apply conventional charging.

Scheme 314

The image shows how the system strives to maintain the battery's SoC and at which temperature and SoC the brake energy regeneration function is permitted.

1. State of charge (SoC).
2. Area where brake energy regeneration is permitted.
3. Parameter of how the system strives to maintain the battery's SoC with regard to the battery's temperature. Above 55 °C charging of the battery does not occur, in principle. This is to prevent, for example, overheating.
4. Battery temperature.
5. Area where the system applies conventional charging.

Scheme 315

The system consists of the following

1. The Engine control module (ECM) is the main module for this function. The control module sends information to the Alternator control module (ACM) about what charge voltage the alternator is to maintain.
2. Alternator control module (ACM) with charge regulator. The control module is controlled by the Engine control module (ECM).
3. Battery monitoring sensor. In order for this function to work, the battery's status must be thoroughly calculated and monitored. The vehicle is therefore equipped with a battery monitoring sensor.
4. Battery.
5. Central electronic module (CEM). If alternator control does not work correctly for any reason, the Central electronic module (CEM) takes over control of the alternator from the Engine control module (ECM). Charging is then conventional.

The sensor on the battery's negative pole indicates that the vehicle has a battery monitoring sensor.

A battery monitoring sensor is always found on vehicles with the automatic start/stop of the engine function.

Scheme 316

1. Primary circuit (1)
2. Secondary circuit (2)
3. Master cylinder
4. Brake control module (BCM)

The hydraulic brake system is a two-circuit diagonal brake system.

The hydraulic brake system is divided up as follows

The primary circuit (1) includes

1. The front chamber for the master cylinder
2. Cylinder in the front left-hand brake caliper
3. Cylinder in the rear right-hand brake caliper.

The secondary circuit (2) includes

1. The rear chamber for the master cylinder
2. Cylinder in the front right-hand brake caliper
3. Cylinder in the rear left-hand brake caliper.

Two brake pipes run from the master cylinder (3) to the brake control module (BCM) (4), where the brake pipes then branch to the wheel brakes.

Servo cylinder

Scheme 317

1. Vacuum hose connection
2. Front push rod
3. Membrane spring
4. Rubber membrane
5. Guide housing
6. Push rod spring
7. Rear push rod
8. Air cleaner (ACL)
9. Connecting device EBA
10. Reaction disc
11. Membrane support.

The vehicle is equipped with a single servo cylinder. It has integrated mechanical brake assistance (EBA). The servo cylinder is located between the brake pedal and the master cylinder and is actuated directly by the brake pedal. It ensures that less pedal force is required when braking with the aid of vacuum from the vacuum pump and via the intake manifold for the engine. The check valve located by the vacuum pump prevents air from flowing back to the servo cylinder.

Mechanical brake assistance (EBA)

Scheme 318

1. Connecting device.

The mechanical brake assistance (EBA) is integrated in the servo cylinder.

The connecting device (1) is designed as a single unit. It is fully integrated in the servo cylinder and only actuates the standard version of the servo cylinder in the guide housing.

The function can shorten the braking distance considerably, as it is activated when the brake pedal is depressed quickly and firmly.

In such a situation, the ability of the servo cylinder to reinforce the brake force is fully utilized.

Master cylinder

Scheme 319

1. Push rod (part of primary piston, connected to the servo cylinder)
2. Primary circuit chamber
3. Valve
4. Secondary circuit piston
5. Secondary circuit chamber.

The master cylinder is designed for a diagonally split brake system.

One front wheel and one rear wheel are connected together in a circuit. The two chambers in the master cylinder supply one circuit each in the brake system.

The master cylinder is of the tandem type. It contains two pistons, which are connected in series. The master cylinder is actuated by the servo cylinder push rod (1) and brake fluid is pressed into the brake pipes when the brake pedal is pressed. The brake fluid, which is moved in the system, generates an increase in pressure in the wheel brakes causing the vehicle to brake.

There is a valve (3) in the bottom of both pistons. These ensure that the remaining pressure in the chambers (for example after braking using ABS) is released, so that the seals in the master cylinder are not damaged. They also ensure that new brake fluid can be added to the system in the event of wear to brake pads and disc brakes.

For safety reasons, each circuit has a specific piston for pressing the brake fluid out of the master cylinder and into the brake pipes.

Springs in the master cylinder move the pistons back to their resting position when the vehicle is not braking. In this situation the valves are open and both the chambers (brake circuits) are connected to the brake fluid reservoir.

When the brake pedal is pressed, both pistons are moved. The valves are closed and pressure can build up in the brake fluid.

The brake fluid reservoir for the master cylinder ensures that the correct amount of brake fluid is supplied in the system, irrespective of wear to brake pads and disc brakes.

Scheme 320

1. Brake caliper
2. Retainer
3. Rubber bushing
4. Sliding pin
5. Brake pads
6. Brake pipe
7. Bleed nipple
8. Piston
9. Brake fluid inlet
10. Sealing ring
11. Dust boot.

The vehicle has disc brakes on all four wheels to ensure optimum braking performance. The foot brake is combined with the parking brake on the rear axle. The brake discs are ventilated on the front axle, integrated with the wheel hub. The brake discs are solid on the rear axle.

The brake caliper (1) comprises two halves joined with screws, positioned over the brake disc. The caliper grips across the disc brake and slides in the holder on two sliding pins (4). The sliding pins are greased and protected with a rubber bushing (3). The braking force from the brake pads (5) is absorbed via the holder (2), which transfers the force to the spindle.

The sliding pins are made of steel. They are screwed into the armature, which is secured to the wheel spindle.

The brake caliper contains a piston (8) together with a sealing ring (10) and dust boot (11). The piston cylinder is made of steel.

The piston presses directly on the inner brake pad against the brake discs. On account of the action-reaction principle the brake caliper (1) is pressed backwards. This movement presses the outer brake pad against the brake disc. (Also, see FOOT BRAKE AND PARKING BRAKE .) The sliding brake caliper's retainer (2) presses the outer brake pad against the brake disc.

The dust boot prevents dirt getting in between the cylinder and piston.

Old brake calipers at the rear are replaced with new calipers filled with brake fluid from the factory. This simplifies bleeding.

The splash guard prevents water and salt from soiling the brake disc. Any soiling results in reduced friction and hence reduced braking power.

Scheme 321

1. Control lever
2. Bracket
3. Primary mechanical cable
4. Adjuster nut
5. Compensator
6. Secondary mechanical cables.

Scheme 322

The control lever (1), in the illustration above, applies to model years up to and including 2007.

The rear brake caliper has an integrated parking brake mechanism.

The mechanism is self-adjusting. Adjustment takes place every time after braking.

The control lever (1) is located between the front seats. The control lever contains a locking arrangement. This is released with the push-button in the lever handle. The control lever is mounted on a shaft. The shaft is mounted in a bracket (2) which is screwed to the tunnel.

On the front end of the primary mechanical cable (3) is an adjuster nut (4) for manual adjustment of the cables. The primary mechanical cable is routed through a hole in the front floor to the compensator (5), where the two secondary mechanical cables (6) are mounted. The secondary mechanical cables are routed crosswise to the relevant brake caliper.

The secondary mechanical cables are routed on the underside of the floor to the cross member under the rear seat, where they are secured in two clamps on either side. They are then routed via a mechanical cable holder in the floor to a clamp in the control arm. The mechanical cable bushing is mounted in the caliper and the end of the cable is mounted in the caliper lever.

Scheme 323

The illustrations above show the rear brake with combined foot brake and parking brake function. The principle for the foot brake function is the same at both front and rear, however.

1. Piston
2. Adjuster screw
3. Adjuster nut
4. Spring holder
5. Return spring
6. Axle
7. Control spring
8. Gasket
9. Throw-out bearing
10. Snap-ring
11. Sealing ring
12. Adjuster piston
13. Arm
14. Eccentric
15. Arm
16. Brake disc
17. Brake caliper
18. Brake pads, outer
19. Brake pads, inner.

VIDA (Volvo scan 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.

DESCRIPTION OF PROGRAMMABLE PARAMETERS, CUSTOMER ADAPTATION

There are two ways of carrying out customer adaptation

1. via the infotainment control module (ICM)
2. via VIDA (Volvo scan tool).

The parameters which can be changed are described in the table below.

Scheme 324

The lock function that is active when the car is delivered depends on the market. The system can be configured for total unlocking or 2 step unlocking.

Total unlocking means that all side doors are unlocked and that the tailgate/trunk lid can be opened by activating the switch on the handle.

During 2 stage unlocking, only the driver's door is unlocked first. If the remote control button is pressed again within 10 seconds, the other doors are unlocked.

Normally the vehicle is unlocked by activating the unlocking button on the remote control. This also deactivates the alarm if installed. Unlocking the car with the key blade should be seen as a last resort. If the car is unlocked with the key blade, the alarm will be triggered. The alarm can be switched off by inserting the ignition key in the ignition switch.

Scheme 325

If there is a keyless entry system, the keyless vehicle module (KVM) checks the identity of the key during locking and unlocking. After checking the key identity, the keyless vehicle module (KVM) then transmits a command to the central electronic module (CEM) to lock or unlock the central locking. The keyless vehicle module (KVM) uses the antennas in the outer handles on the side doors and in the rear bumper to check the identity of the key.

The key is checked when a handle on the side doors is pulled out or if the switch on the tailgate is activated. The keyless vehicle module (KVM) then activates one or more of the outer antennas to check the identity of the key. If the key is approved, the keyless vehicle module (KVM) transmits a signal to the central electronic module (CEM) which unlocks the vehicle.

The vehicle is locked using the lock buttons on the door handles. During locking, the antenna is also activated to check that there is an authorized key in the vicinity of the vehicle. If the key is approved, the keyless vehicle module (KVM) transmits a signal to the central electronic module (CEM) to lock the vehicle.

Scheme 326

If lock units with deadlocking are installed, there is an additional lock motor in each lock unit. The function of this lock motor is to mechanically disengage the inner door handle. Deadlocking is activated automatically 25 seconds after the vehicle was locked. It will not then be possible to open a side door from the inside, even if a window is smashed. This also means that anyone still in the vehicle when it is locked cannot get out. The function can be disengaged using the switch for reduced alarm which is in the front interior lighting panel in the roof.

Scheme 327

The private locking function prevents entry to certain areas and functions in the vehicle. The function is only available on the S40 and C70.

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 328

The tailgate/trunk lid can be opened in three ways

1. via the switch on the tailgate/trunk lid if the vehicle is unlocked
2. keyless
3. via a switch in the center console under the mug holder.

The lock motor for the tailgate/trunk lid is directly connected to the central electronic module (CEM).

The switch on the tailgate or trunk lid is directly connected to the keyless vehicle module (KVM) and to the central electronic module (CEM).

When the switch is pressed in, the keyless vehicle module (KVM) activates the antenna in the bumper and begins checking for an authorized key using keyless functionality. If an authorized key is found, the keyless vehicle module (KVM) transmits a signal to the central electronic module (CEM) to activate the lock motor in the trunk lid or tailgate. The tailgate/trunk lid is not opened if valet 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 be opened, the lock motor is powered for approximately 0.5 seconds or until the central electronic module (CEM) receives a signal from the door open sensor in the lock motor indicating 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 329

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 in USA/CDN.

Scheme 330

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

Further light functions are included in the central locking system

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 lamps
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 lamps
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 331

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

1. contact breaker which indicates that the door is not closed (door open sensor)
2. contact breaker to indicate that the central locking motor is in the locked position.

The door open sensors are connected directly 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.

SYSTEM DESCRIPTION/DESIGN

The central locking system with keyless functionality is a distributed system. The components of the system are

1. central electronic module (CEM)
2. keyless vehicle module (KVM)
3. driver door module (DDM)
4. passenger door module (PCM)
5. driver information module (DIM)
6. phone module (PHM)
7. infotainment control module (ICM)
8. Convertible Roof Module (CRM)
9. switch for valet locking
10. switch for unlocking the fuel tank filler cover
11. lock motor units in the doors
12. lock motor at the fuel tank filler cover
13. lock motor for the trunk lid/tailgate
14. remote keyless entry (RKE) receiver
15. Supplemental restraint system module (SRS)
16. indicator LED in the doors
17. lockable storage compartment
18. lock for ski hatch

There are two ways of carrying out customer adaptation

1. via the infotainment control module (ICM)
2. via VIDA (Volvo scan tool).

The parameters which can be changed are described in the table below.

Scheme 332

The lock function that is active when the car is delivered depends on the market. The system can be configured for total unlocking or 2 step unlocking.

Total unlocking means that all side doors are unlocked and that the tailgate/trunk lid can be opened by activating the switch on the handle.

During 2 stage unlocking, only the driver's door is unlocked first. If the remote control button is pressed again within 10 seconds, the other doors are unlocked.

Normally the vehicle is unlocked by activating the unlocking button on the remote control. This also deactivates the alarm if installed. Unlocking the car with the key blade should be seen as a last resort. If the car is unlocked with the key blade, the alarm will be triggered. The alarm can be switched off by inserting the ignition key in the ignition switch.

Scheme 333

When the system for keyless locking system is installed it is Keyless vehicle module (KVM) that checks the key's identity when unlocking and locking. After this check, Keyless vehicle module (KVM) sends a command to Central electronic module (CEM) that the central locks shall be unlocked or locked.

Keyless vehicle module (KVM) checks the key's identity using antennas in the external handles on the side doors (C30/C70 front doors, S40/V50 rear doors) and in the rear bumper.

The key is checked when a handle on the side doors is pulled out or if the switch on the tailgate is activated. The keyless vehicle module (KVM) then activates one or more of the outer antennas to check the identity of the key. If the key is approved, the keyless vehicle module (KVM) transmits a signal to the central electronic module (CEM) which unlocks the vehicle.

The vehicle is locked using the lock buttons on the door handles. During locking, the antenna is also activated to check that there is an authorized key in the vicinity of the vehicle. If the key is approved, the keyless vehicle module (KVM) transmits a signal to the central electronic module (CEM) to lock the vehicle.

Scheme 334

If lock units with deadlocking are installed, there is an additional lock motor in each lock unit. The function of this lock motor is to mechanically disengage the inner door handle. Deadlocking is activated automatically 25 seconds after the vehicle was locked. It will not then be possible to open a side door from the inside, even if a window is smashed. This also means that anyone still in the vehicle when it is locked cannot get out. The function can be disengaged using the switch for reduced alarm which is in the front interior lighting panel in the roof.

The central locking system with keyless functionality is a distributed system. The components of the system are

1. central electronic module (CEM)
2. keyless vehicle module (KVM)
3. driver door module (DDM)
4. passenger door module (PCM)
5. driver information module (DIM)
6. phone module (PHM)
7. infotainment control module (ICM)
8. convertible Roof Module (CRM)
9. switch for valet locking
10. switch for unlocking the fuel tank filler cover
11. lock motor units in the doors
12. lock motor at the fuel tank filler cover
13. lock motor for the trunk lid/tailgate
14. remote keyless entry (RKE) receiver
15. supplemental restraint system module (SRS)
16. indicator LED in the doors
17. lockable storage compartment
18. lock for ski hatch.

Scheme 335

The central electronic module (CEM) (4/56) controls and monitors the central locking system and its functions. No door which is part of the central locking system can be unlocked without a command from the central electronic module (CEM). Most of the system settings are stored in the central electronic module (CEM). Many of these settings are market dependent. For information about the settings which can be made, see: DESCRIPTION OF PROGRAMMABLE PARAMETERS, CUSTOMER ADAPTATION

The central electronic module (CEM) continually checks the system to monitor the status of the doors and lock motors.

Scheme 336

The keyless vehicle module (KVM) controls keyless entry to the vehicle. The system allows the vehicle to be opened without inserting a key in the lock or pressing a button on the remote control. The control module is under the left front seat. The keyless vehicle module (KVM) works together with the central electronic module (CEM) when opening and starting the vehicle. The two control modules communicate via the low speed side of the controller area network (CAN) (LS-CAN).

There are a number of components in the keyless entry system

1. keyless vehicle module (KVM)
2. antennas in external door handles (C30/C70 front doors, S40/V50 rear doors) and in rear bumper
3. antennas in the passenger compartment and cargo compartment
4. quick lock motors connected to the standard lock motors
5. switches in door handles, locking buttons and additional lock motors
6. remote Keyless Entry (RKE) for signals from the keyless remote control
7. remote control including keyless entry function.

When one of the external door handles is pulled outward, Keyless vehicle module (KVM) activates the antennas in the handles (C30/C70 front doors, S40/V50 rear doors) on the corresponding side. A message is sent from the antennas and the purpose is to check if there is a remote control with keyless function by the vehicle. The remote control answer to Remote Keyless Entry (RKE) which transmits the information on to Keyless vehicle module (KVM). If a remote control is found, then Keyless vehicle module (KVM) checks the remote control's identity. If the remote control is programmed for use in the vehicle, Keyless vehicle module (KVM) will activate the quick-lock motor to open the door where the handle was pulled out. At the same time, Keyless vehicle module (KVM) sends a signal to Central electronic module (CEM) that the key is approved and that the other doors can be unlocked.

Note. During locking, the keyless vehicle module (KVM) only checks the quick-lock motors in the doors. The other lock motors and the other functions in the central locking system are checked by the central electronic module (CEM).

Scheme 337

The driver door module (DDM) (3/126) and passenger door module (PCM) (3/127) are identical in appearance. The only difference between the two units are the software downloaded into them after installation in the vehicle. There are also different control panels connected to the control modules. The door control modules communicate with the central electronic module (CEM) via the low speed side of the CAN network (LS-CAN).

The control panel on the driver's side has control buttons for adjusting the door mirrors, window lift mechanisms and the button for activating child-proof locking (not C70).

The control panel on the passenger side has control buttons for the power window mechanism.

There is also a button for locking and unlocking the central locking by the inner door handle on each side.

The door control modules are directly connected to the lock unit in each door. The door control modules lock and unlock the door on receipt of a command from the central electronic module (CEM). The door control modules can only unlock the door on receipt of a signal from the central electronic module (CEM).

Scheme 338

The driver information module (DIM) (5/1) displays a text message and lights a warning lamps if any of the side doors or tailgate/trunk lid or hood have been opened while driving. A micro-switch indicates that the doors or tailgate/trunk lid are fully closed. Only cars with an alarm have a micro-switch at the engine hood.

A yellow warning lamp lights if the vehicle speed is below 7 km/h (5 mph). The red warning lamp lights if the vehicle speed is above 7 km/h (5 mph).

The tailgate is only indicated by a text message and yellow warning lamp, irrespective of the speed.

The Driver information module (DIM) also displays a message if a passive key cannot be found when a start attempt is carried out or if a remote control that is used to start the vehicle cannot be found after the driver's door has been opened and closed.

Scheme 339

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 (LS-CAN). 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 340

The customer can personalize some of the central locking settings using the infotainment control module (ICM) (16/1) and the keyless entry system. The infotainment control module (ICM) communicates with the central electronic module (CEM) and keyless vehicle module (KVM) via the low speed side of the CAN network (LS-CAN). 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 settings for the central locking system are stored in the central electronic module (CEM). The settings for the keyless entry system are stored in the keyless vehicle module (KVM). Information from both control modules is transmitted to the infotainment control module (ICM) when the ignition is switched on.

Scheme 341

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). Applies to the C70: Valet locking also includes lockable storage compartments and the lock for the ski hatch.

Scheme 342

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 343

Note. C70 only has the front locking units.

The lock units are installed 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 four versions of the lock units in the front doors with lock motors for

1. central locking
2. central locking and deadlocking
3. central locking and quick locking
4. central locking, deadlocking and quick locking.

The central locking lock motor locks the door.

The quick lock motor is hardwired to the keyless vehicle module (KVM) and opens the door upon receipt of a command from the keyless vehicle module (KVM).

Note. Quick-locks are controlled entirely by the keyless vehicle module (KVM).

The door control modules can only activate the lock motors 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 which indicates that the door is not locked

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.

When the quick locks are activated by the keyless vehicle module (KVM), the catches in the standard lock units are released from the striker plates in the car body. The quick locks contains a switch which is acted on by a control arm from the door handle. This switch is closed when the door handle is pulled out fully. This switch must be closed for the keyless vehicle module (KVM) to activate the quick lock.