Part 1

Design

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.

Headlamps





Warning! Both the power stage, which is built into the light housing, and the wiring for the Bi-Xenon lights, are high voltage.

The headlamps are operated via the light switch module (LSM), which is located on the dashboard at the side of the steering wheel. The light switch module (LSM) is connected to the central electronic module (CEM) via LIN communication. Low and high beam are operated by moving the left-hand control stalk toward 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.
For more information on Bi-Xenon lamps see Design and Function, Headlamp control module (HCM).
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.
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.
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.

Parking lights / number plate lighting




There are a number of lamps positioned around the car to mark its position. These are in the headlamps and tail lights. The lamps light together with the license plate lighting when the light switch module (LSM) is in parking light mode or low beam is on.
Power is supplied to the lamps from the central electronic module (CEM).
There are diagnostics for the light switch module (LSM) and the lamps.

Front fog lamps




If the car has front fog lamps, these are in the bumper casing below the headlamps.
The fog lights are operated via a button in the light switch module (LSM). An LED in the button illuminates when the fog lights are on.
The light switch module (LSM) is directly connected to the central electronic module (CEM). Power is supplied to the lamps via a direction connected relay on the central electronic module (CEM).

Rear fog lamp




The lamps of the rear fog lights are located in the tail lights. The fog lights are operated via a button in the light switch module (LSM). An LED in the button and a symbol in the driver information module (DIM) illuminate when the fog lights are on. The rear fog lights 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). Power is supplied to the lamps directly via an output on the central electronic module (CEM).
Upon reactivation of ignition switch position II, the function is set to deactivated 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.

Back-up lamp




There are two reversing lights located in the tail lights. The reversing lights come on when reverse gear is selected. The reversing lights 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.
To detect faults in the reversing lights, the central electronic module (CEM) reads power consumption in 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 (DIM).

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




A high-mounted brake light is mounted at the top edge of the rear window. This light comes on together with the standard brake lights during braking. It is activated when the brake light 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 and headlamps




The windshield wipers are operated by a motor located beneath the plenum chamber cover. Washer jets are located on the hood and bumper shell for windshield and headlamp washing. The jets are connected to two different pump motors on the washer fluid reservoir, which is located at the front right of the engine compartment. One pump motor is used for high pressure washing of the headlamps while the other is used for windshield washing.
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 headlamp washer is activated in two brief intervals. After that, the windshield washer must be activated 5 times before two additional brief headlamp wash intervals can occur. This does not apply if a period of 10 minutes has elapsed since the previous washing. The headlamp washers are not activated if there is less than 1 liter of fluid in the washer fluid reservoir.
To clean the rear window, move the stalk in the direction away from the steering wheel, activating the pump motor which also is used for cleaning the windshield. To operate the rear window wiper, there is a button on the end of the stalk.
The steering wheel module (SWM) sends information on control stalk position to the central electronic module (CEM) via LIN communication. The central electronic module (CEM) also receives a signal from the wiper motor if the wipers are in their park position.
The wiper motor module (WMM) is powered directly via 30-feed.
The washer motor for the windshield and rear window washers as well as the rear window wiper is supplied with voltage via a directly connected relay located on Central electronic module (CEM).
The washer motor for the headlights is supplied with voltage via a relay located in the relay and fuse box 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




There are various lamps inside the passenger compartment, such as the courtesy lighting and glove compartment lighting for example.
The lamps for courtesy lighting are in the soundproofing panel on the driver and passenger sides. The lamp for the glove compartment is at the top of the glove compartment.

Interior roof lighting




Inside there are a number of lamps with different purposes. There are up to four lamps which light when the general lighting is on.
Two of the reading lamps, (front left and front right) are in a unit in the roof immediately above the rear view mirror. The two rear reading lamps (option, market dependent) are in the roof above the rear seat.
The lighting time from when the door is unlocked or closed or from when the engine is switched off is 30 seconds.
The lighting time from the door being left open or from a lamp being activated with a button until the interior lighting goes out is 5 minutes.
For the inner roof lighting to work, the relay for interior lighting must be activated. The central electronic module (CEM) activates the relay via an output.