Part 1
Design
Alarm
See Design and Function, Alarm.
Locks
See Design and Function, Central locking.
Immobilizer
See Design and Function, Immobilizer/start inhibition.
Alcolock (option 2009-)
See Design and Function, Alcohol Analyzing Start Inhibitor.
Automatic start/stop of engine (2010-)
See Design and Function, Automatic start/stop of engine (2010-, only on vehicles with the function automatic start/stop of engine)
Current limiting
The central electronic module (CEM) checks and sometimes limits the current from the battery and generator. The central electronic module (CEM) can prioritize between different loads in the prevailing conditions.
If there is a fault with current limitation, the general warning lamp will light in the driver information module (DIM) and a text message will be displayed.
Generator (GEN) (Alternator control module (ACM))
See Design and Function, Generator (GEN) and Design and Function, Engine control module (ECM).
See also Design and Function, Regenerating brake energy (2010-).
Secondary battery (2010-, only on vehicles with the function automatic start/stop of engine).
The secondary battery is used in the function automatic start/stop of engine, see Design and Function, Automatic start/stop of engine.
The secondary battery is only connected to the vehicle's electrical system when the engine is restarted after autostop and when the secondary battery needs to be charged. Connecting the secondary battery to the vehicle's electrical system is controlled by Engine control module (ECM) via a relay.
Central electronic module (CEM) is monitors the secondary battery's voltage and controls the secondary battery's charging.
When the secondary battery needs charging the Central electronic module (CEM) sends a request to Engine control module (ECM) to connect the secondary battery to the vehicle's electrical system. When the alternator is charging and secondary battery is connected, the battery is charged.
Note! When restarting the engine, it is only Engine control module (ECM) that controls connection of the secondary battery.
When the engine is on (alternator charging) and the secondary battery is connected to the vehicle's electrical system, the secondary battery's voltage will be the same as the rest of the electrical system's voltage. If the secondary battery is disconnected, the voltage will be lower.
See also Design and Function, Automatic start/stop of engine.
The secondary battery's voltage can be diagnosed.
The battery monitor sensor (BMS) (only vehicles with the function for brake energy regeneration 201020-)
Note! From structure week 201020- the battery monitoring sensor (BMS) is LIN-connected to Central electronic module (CEM) instead of to Engine control module (ECM) as before. (For D4164T the battery monitoring sensor is still connected to Engine control module (ECM).)
The battery monitoring module is fitted on the battery's negative terminal and its main function is to monitor battery status.
For more information about battery monitoring sensor (BMS) function, see: Design and Function, Brake energy regeneration.
Headlamps
Warning! The ballast, which is located in the wheel arch liner, and the wiring for the Bi-Xenon lamps are high voltage.For S40/V50 (200720-), C30/C70 (200946-), the ballast is integrated in the headlight.
The headlamps are operated via the light switch module (LSM). This is on the dashboard at the side of the steering wheel. The light switch module (LSM) is directly connected to the central electronic module (CEM). Low and high beam are operated by moving the left-hand control stalk towards the steering wheel.
Low beam is powered directly by the central electronic module (CEM). High beam is powered via a directly connected relay on the central electronic module (CEM). The level of the supply voltage to the low beam is regulated by the central electronic module (CEM). When the supply voltage is sufficient (in excess of 13 V), pulse width modulation is used to maintain the voltage level at 13.0 V +/- 0.2 V. This does not apply to cars with Bi-Xenon lamps.
Cars with Bi-Xenon lamps are powered directly via the central electronic module (CEM) without pulse width modulation.
Warning! The ballast, which is located in the wheel arch liner, and the wiring for the Bi-Xenon lamps are high voltage.For S40/V50 (200720-), C30/C70 (200946-), the ballast is integrated in the headlight.
In Bi-Xenon lamps, the reflector in the lamp housing is moved by an actuator motor when changing between high and low beam. The actuator motor is integrated in the lamp housing.
To detect problems with the low beam, the central electronic module (CEM) reads the power consumption of the circuit. If this falls below a certain threshold value a fault will be indicated. The general warning lamp lights in the driver information module (DIM) and a text message is displayed.
There are diagnostics for the high beam relay.
There are also diagnostics for the high and low beam function (actuator motor) for Bi-Xenon lamps.
For more information on Bi-Xenon lights:
S40/V50:
See: Design and Function, GDL-lights (-200719).
See: Design and Function, Headlamp Control Module (HCM) (200720-).
C30/C70:
See: Design and Function, GDL-lights (-200945).
See: Design and Function, Headlamp Control Module (HCM) (200946-).
Right and left-hand asymmetric lamps
The right and left-hand asymmetric lamps are adjusted mechanically using a simple operation. A lever is accessible when the rear cover on the headlamp housing is opened.
Halogen
A = left-hand asymmetric
B = right-hand asymmetric
Bi-Xenon
A = left-hand asymmetric
B = right-hand asymmetric
Headlamp range adjustment (certain markets)
There are two motors which angle the headlamps upwards or downwards to control the range of the beam. The motors are integrated in the headlamps.
The motors are controlled by a thumb wheel which is located in the light switch module (LSM) on the dashboard by the side of the steering wheel.
If the thumb wheel is turned, information is transmitted to the motors which adjust the headlamps accordingly.
Automatic range adjustment (Bi-Xenon)
S40/V50:
See: Design and Function - GDL-lights (-200719).
See: Design and Function, Headlamp Control Module (HCM) (200720-).
C30/C70:
See Design and Function, GDL-lights (-200945).
See: Design and Function, Headlamp Control Module (HCM) (200946-).
Headlamp range adjustment position sensors (Bi-Xenon)
S40/V50:
See: Design and Function - GDL-lights (-200719).
See: Design and Function, Headlamp Control Module (HCM) (200720-).
C30/C70:
See: Design and Function, GDL-lights (-200945).
See: Design and Function, Headlamp Control Module (HCM) (200946-).
Parking lights / number plate lighting
There are a number of lamps positioned around the car to mark its position. These are in the headlamps, tail lamps and on the front fenders (US model). The lamps light together with the number plate lighting when the light switch module (LSM) is in parking lamp mode or low beam is on.
The lamps are powered directly via two outputs on the central electronic module (CEM). One of the outputs powers:
- the front left-hand parking lamp
- the left-hand parking lamps
- the license plate lighting
- the rear right-hand parking lamp.
The other output powers:
- the front right-hand parking lamp
- the right-hand side parking lamps
- the rear left-hand parking lamp.
There are diagnostics for the light switch module (LSM) and the lamps.
Front fog lamps
If the car is equipped with front fog lights, these are in the bumper casing below the headlights.
The fog lamps are operated via a button in the light switch module (LSM). An LED in the button lights when the fog lamps are activated. The light switch module (LSM) is directly connected to the central electronic module (CEM). The lamps are powered via a directly connected relay on the central electronic module (CEM).
There are diagnostics for the fog lamp relay (front).
Daytime running lights (from structure week 201044, option)
If the vehicle is equipped with daytime running lights, these are located in the bumper casing below the headlights where the front fog lights otherwise would be installed.
Light switch module (LSM) is directly connected to Central electronic module (CEM). The lights are supplied with voltage via a directly connected relay from Central electronic module (CEM), the same relay that normally supplies voltage to the front fog lights.
The relay for daytime running lights/front fog lights can be diagnosed.
Rear fog lamp
The rear fog lamp are in the tail lamps. The fog lamps are operated via a button in the light switch module (LSM). An LED in the button lights when the fog lamps are activated. The rear fog lamp can only be activated when low beam is on (market dependent). The light switch module (LSM) is directly connected to the central electronic module (CEM). The lamps are powered directly via an output on the central electronic module (CEM).
When reactivating key position II, the function is set to de-activated mode.
To detect faults in the rear fog lamps, the central electronic module (CEM) reads the power consumption of the circuit. If the power consumption falls below a certain limit, a fault is indicated and a text message is displayed in the driver information module.
There are diagnostics for the rear fog lamps.
Back-up lamp
There are two back-up (reversing) lamps. These are in the tail lamps. The back-up (reversing) lamp lights when back-up (reverse) gear is selected. The back-up (reversing) lamps are connected to the central electronic module (CEM) via a directly connected relay. The lamps are powered via the relay.
Cars with manual transmissions
Cars with manual transmissions have a back-up (reverse) switch on the transmission. The switch closes and transmits a directly connected signal to the central electronic module (CEM) when back-up (reverse) gear is selected.
Cars with automatic transmissions
In cars with automatic transmissions, a signal is transmitted from the transmission control module (TCM) on the controller area network (CAN) to the central electronic module (CEM) indicating that back-up (reverse) gear is selected.
There are diagnostics for the back-up (reversing) lamp relay.
Brake light
The stop lamps are in the tail lamps. The lamps light when the stop lamp switch on the brake pedal is closed. The stop lamp switch is connected to the central electronic module (CEM). The lamps are powered directly via an output on the central electronic module (CEM).
The stop lamps function even when the ignition is not on. When the ignition is not on, the central electronic module (CEM) is still powered. However the module is in a current saving mode. If the stop lamp switch is activated, the central electronic module (CEM) will also be activated and the stop lamps will come on.
To detect faults in the stop lamps, the central electronic module (CEM) reads the power consumption of the lamp circuit. If the power consumption falls below a certain limit, a fault is indicated and a text message is displayed in the driver information module.
High level stop lamp
There is a high level stop lamp at the top of the rear windshield. This lamp lights during braking together with the standard stop lamps. It is activated when the switch on the brake pedal is closed.
The high level stop lamp is powered directly from the central electronic module (CEM). The lamp consists of a number of LEDs.
There are diagnostics for the high level stop lamp.
Turn signal lamps / Hazard warning signal flashers
There are six lamps around the car to indicate direction changes. These are in the headlamps, tail lamps and in the door mirrors.
The turn signal lamps are operated using the left-hand control stalk.
To cancel the hazard warning signal flashers, where all the turn signal lights flash, press in the button for the hazard warning signal flasher. This is positioned in the middle of the dashboard by the center air vents.
The front and rear lamps are powered directly from the central electronic module (CEM). The lamps in the door mirrors are powered directly from the control module in each door, the driver door module (DDM) or the passenger door module (PDM).
A signal is also sent to the bulb in the hazard warning signal flasher switch when this function is activated.
The central electronic module (CEM) monitors the power consumption on each side to check for bulb faults. If the power consumption falls below a certain threshold value, a fault is indicated and the frequency of the signal to the bulbs is doubled on the side of the blown lamp.
There are diagnostics for the front and rear turn signal lamps.
Wiper/washers for the windshield/rear window/ headlights
Note! Rear window wiper and washer are only available on C30 and V50.
The windshield wipers are powered by a motor positioned under the cowl. There are also washer nozzles on the hood and bumper cover for cleaning the windshield and headlamps. For cars with five doors, there is also a wiper and washer nozzle for the rear windshield. The washer nozzles are connected to two different pump motors on the windshield washer reservoir at the front right of the engine compartment. One pump motor is for high-pressure cleaning of the headlamps. The other pump is for washing the front and rear windshields (5 door).
The windshield wipers are operated using the right-hand control stalk. There are three positions:
- intermittent
- low speed
- high speed.
The time between strokes for intermittent wiping is adjusted using a ring on the control stalk.
Pull the control stalk towards the steering wheel to clean the windshield. The washers for the headlamps are activated simultaneously.
The washers for the headlamps are activated in two short intervals. Then the washer for the windshield must be activated 5 times before a further two short headlamp washes take place. Alternatively the interval is 10 minutes. The headlamp washers are not activated if the level in the windshield washer reservoir is below 0.7 liters.
Push the control stalk away from the steering wheel to clean the rear windshield. There is a button at the end of the control stalk to control the rear wiper.
Information about the position of the control stalk is transmitted to the central electronic module (CEM) on the controller area network (CAN). The central electronic module (CEM) also receives a signal from the wiper motor if the wipers are in the park position.
The central electronic module (CEM) also monitors the windshield washer reservoir level via a level sensor in the reservoir. The switch in the level sensor closes if the level falls below 0.7 liters. A text message indicating that the windshield washer fluid needs to be topped up then lights in the driver information module (DIM).
The wiper motor module (WMM) is powered directly via a 30-supply.
The washer motor for the front and rear windshields is powered via directly connected relays which are on the central electronic module (CEM). The headlamp washers are supplied via a relay in the combined relay and fusebox in the engine compartment.
There are diagnostics for the wiper motor module (WMM) and the relays for the washer pump motors.
Courtesy lighting/glove compartment lighting