Description And Operation: Operation

Following are paragraphs that briefly describe the operation of each of the major exterior lighting systems. The lamps and the hard wired circuits between components related to the exterior lighting system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes appropriate SYSTEM WIRING DIAGRAMS, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the exterior lighting system or the electronic controls or communication between modules and other devices that provide some features of the exterior lighting system. The most reliable, efficient, and accurate means to diagnose the exterior lighting system or the electronic controls and communication related to exterior lighting system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

BRAKE LAMPS

The vehicle brake lights are located at the rear in the side light clusters and in the centered third brake light.
The side brake lights located in the rear light clusters are standard incandescent bulbs.
The center light is formed by an LED device, located in the middle of the tailgate. The brake lights are operated each time the brake pedal is pressed via the special switch on the pedal.
The switch fitted on the pedal unit consists of two contacts which supply two signals: the first is N.A. type, which recognizes the position of the brake pedal if it is not in the rest position, i.e. the pedal is pressed; the second is N.C. type, which recognizes the position of the brake pedal in the rest position. The lights are switched on by the N.O. contact (pedal pressed).
The control function is activated key ON and the command from the contact of the switch.
The brake lights check function monitors that the side lights are working correctly: the following are checked:
- open circuit or missing bulb;
- short circuit to ground (bulb or wiring to ground);
- short circuit to battery voltage (wiring short circuited to batt).
The continuity of the fuse protecting the switch on the brake pedal is also checked. When one of the situations described above is verified, the BCM makes the failure status available to the CAN: a special lights failure warning light switches on in the instrument panel and, at the same time, the information is shown in the display by means of the specific symbol.
The switch receives power supply from the BCM. When the brake pedal is pressed, the switch closes and sends the N.O. signal to the BCM.
The BCM receives a direct power supply from the battery through the line protected by a maxi fuse in the engine compartment junction unit.
The BCM receives an ignition-operated power supply (INT). This signal is used, amongst other things, to "wake up the network".
The BCM controls the power supply for the high beam headlights.
The BCM is connected via the CAN line to the instrument panel to manage the "lights failure" warning light and the "brake lights" signal if problems are detected in the circuit or in the fuse.

DAYTIME RUNNING LAMPS - The car is equipped with DRLs (Daytime Running Lights) on all versions. Lights are located in the two lower light clusters.

This function is activated automatically when the car is started up: with the key at ON position and the ring nut turned to "0", the daytime running lights switch on automatically; the other lights and the internal lighting remain off.

The side lights/front daytime running lights are built into the lower headlight and consist of standard incandescent bulbs.

The rear side lights are located in the rear side light clusters and contain standard incandescent bulbs.

With the ignition in the ON position, when the ring nut is turned forwards the dipped beam headlights are activated, the daytime lights switch off and the side lights, dipped beam headlights and number plate lights are switched on.

The side lights warning light in the instrument panel lights up.

The "Follow me home" function allows the dipped beam headlights and the side lights to remain on even after the engine has been switched off (key in STOP position or extracted) for a period of 30 seconds or multiples thereof. The "side lights" warning light in the instrument panel signals that the lights are on.

The switching on of the side lights is managed by the BCM.

There is a single ground signal sent by the light control to the BCM that manages both the side lights and the dipped beam headlights. The signal sent is coded by means of resistive dividers so that multiple information can be sent to the BCM via a single connection.

Activation and/or deactivation information is sent via the CAN: in this way, the side lights warning light in the instrument panel is also activated.

The correct operation of the lights is checked by the daytime lights, side lights and number plate lights "check" function: the following is checked for each of the circuits:

open circuit or missing bulb;
short circuit to ground (bulb or wiring to ground);
short circuit to battery voltage (wiring short circuited to batt).

When one of the situations described above occurs, the BCM makes the failure status available to the CAN: a special "light failure" warning light switches on in the instrument panel display.

FOG LAMPS

The vehicle is equipped with two additional fog lights, located in the front fascia.
The fog lights are activated with the relevant control integrated in the light switch.
When the lights are on, the "fog lights" warning light in the instrument panel lights up.
The switching on of the fog lights is managed by the Body Computer. The lights are activated by:
- key to ON signal (INT);
- a control signal coming from the switch;
- the side lights on signal.
If the side lights are turned off, the fog lights are deactivated even if the operating button is pressed. When the side lights are switched on again, the fog lights do not come on automatically, but only when the button is pressed again.
If the key is switched off (STOP position) and then switched back to ON, the relevant button must be activated again to turn on the fog lights.
When the side lights are switched on again, the fog lights do not come on automatically, but only when the button is pressed again.
The ground signal for activating the fog lights reaches from the control button on light switch. The connection with the BCM for fog light and rear fog light activation signal is the same, but the signal is different because the resistance values in series with the two different switches located in the controls are different.
The BCM receives a direct power supply from the battery through the line protected by a maxi fuse in the engine compartment junction unit.
The BCM receives an ignition-operated power supply (INT). This signal is used, amongst other things, to "wake up the network".
The BCM controls the power supply for the fog lights in the headlights connector C.
The BCM is connected via the CAN line to instrument panel to manage the "fog lights" warning light

The BCM also sends the appropriate electronic messages to the Instrument Panel Cluster (IPC) over the CAN data bus to illuminate or extinguish the front fog lamp indicator. The BCM will automatically de-energize the front fog lamps any time the headlamps are turned OFF or the headlamp high beams are selected.

Each front fog lamp includes an integral adjustment screw to be used for static aiming of the fog lamp beams.

HEADLAMPS

Low Beam

The dipped headlights are built into the upper headlight.
The dipped beam headlights are switched on by turning the ring nut forwards: the dipped beam headlights are activated, the daytime running lights switch off and the side lights, dipped beam headlights and number plate lights switch on. The "dipped beam headlights" warning light comes on in the instrument panel.
On some versions, the dipped beam headlights are also activated automatically by the dusk sensor.
- This sensor, located on the windshield under the interior rear view mirror, detects the variations in outside brightness depending on the light setting: the greater the sensitivity, the less external light is required to activate the exterior lights.
- The setting of the dusk sensor can be adjusted using the instrument panel setup menu.
- When the ring nut is turned in the opposite direction (AUTO position) the side lights and the dipped beam headlights automatically switch on simultaneously depending on the exterior brightness.
- The headlights can only be flashed with the sensor on.
- The main beam headlights will switch off followed after approximately 10 seconds by the side lights, when the sensor is deactivated.
- If a fault is detected with the dusk sensor, the "general failure" warning light is switched on and the information is shown simultaneously on the display.
- The switching on of the dipped beam headlights is managed by the Body Computer.

The BCM receives a direct power supply from the battery through the line protected by a maxi fuse located in the engine compartment junction unit. The BCM receives an ignition-operated power supply and this signal is used, amongst other things, to "wake up the network".

The BCM controls the power supply for the dipped beam headlights. The dipped beam headlights are activated also if the dusk sensor integrated with the rain sensor. The rain/dusk sensor power is supplied by the INT line.

The BCM is connected via the CAN line to the instrument panel to manage the "dipped beam headlights" warning light, the "failure" warning light and, if the dusk sensor fails, the dedicated signal.

High Beam

The vehicle is equipped with two high beams in the upper headlights.
It is the same bulb used for the low beam function, in which a metal shade is lowered for low beam operation and raised for high beam operation.
The main beam headlamps are switched on from the steering column stalk:
- with the low beam headlights on, by pushing the lever towards the dashboard
- in flashing mode, by pulling the stalk toward the steering wheel
The switching on of the main beam headlamps is managed by the BCM. Activation and/or deactivation information is sent via the CAN: in this way, the "high beam" warning light is activated in the instrument panel.
It is not possible to switch on the main beam headlights constantly if the automatic control system is activated by the dusk sensor.
There is a single ground signal sent by the steering column stalk to the BCM that manages the high beam headlights in both fixed and flashing mode. The signal sent is coded by means of resistive dividers so that multiple information can be sent by the steering column stalk to the BCM via a single connection.
The BCM receives a direct power supply from the battery through the line protected by a maxi fuse in the engine compartment junction unit.
The BCM receives an ignition-operated power supply (INT). This signal is used, amongst other things, to "wake up the network".
The BCM controls the power supply for the high beam headlights.
The BCM is connected through the CAN line to the instrument panel to manage the "high beam headlights on" warning light

Each headlamp includes an integral reflector adjustment screw to be used for static aiming of the headlamps.

HEADLAMP LEVELING - The adjustment of main beam headlight alignment according to the load is carried out by means of a regulating device (located inside the upper headlights) which tilts them appropriately, lowering the light beam if the vehicle is heavily laden and raising it if the load lessens.

A roller integrated in the light switch can be used to adjust alignment of the headlights in four pre-defined positions from 0 to 3:

position 1: four persons;
position 2: four persons with full luggage compartment (about 50 kg);
position 3: driver and maximum, load all stowed in the luggage compartment (full load).

Power supply for the motors reaches the headlights from the "ignition-operated" (INT) line protected by a fuse located in the BCM.

The BCM also supplies power to the adjustment motors inside the upper headlights.

LICENSE PLATE LAMPS - The number plate light and numerous other interior lights for lighting the passenger compartment, instruments and controls are activated together with the side lights.

The switching on of the side lights is managed by the BCM.

REVERSE / BACKUP LAMPS

The car is equipped with a reversing light - white incandescent bulb - located in the rear light cluster (passenger side). It is activated each time reverse gear is engaged: this information is received through a switch located on the outside of the automatic transmission casing. Other versions with automatic transmission, this information will also come from the automatic transmission (AC) control unit.
The reversing light switch is supplied by an ignition-operated line protected by a dedicated fuse in the BCM.
The reverse engagement signal is sent to the Powertrain Control Module (PCM) and from this, via the CAN, to the BCM which switches on the lights in question and also controls the automatic operation of the rear window wiper, the electrochromic rear view mirror and the parking sensor control unit, etc.
The switch for the reversing lights receives an ignition-operated (INT) from the BCM.
The BCM receives a direct power supply from the battery through the line protected by maxi fuse in the engine compartment junction unit.
The BCM receives an ignition-operated power supply (INT). This signal is used, amongst other things, to "wake up the network".
When the reverse gear is engaged, the switch closes and sends a signal to the PCM. From this unit the signal is then sent via the CAN to the BCM and to the other nodes involved. The BCM controls the power supply for the reversing lights in the rear light cluster.

TURN SIGNAL / HAZARD LAMPS

The front (located in the lower headlights) and rear (located in the side light clusters) direction indicators (located in the door mirrors) as well as the side ones are standard incandescent bulbs.
The left and right direction indicators are switched on by raising or lowering the special left steering column stalk; the function is activated with the key in the ON position.
The hazard warning lights (left and right direction indicators operated simultaneously) are activated via a button in the center of the dashboard and all the direction indicators are activated at the same time. This function is always active for safety reasons.
The device also has a lane change function: when the stalk is placed in an unstable position for less than half a second (lane change) the direction indicator on the side selected is activated for 5 flashes and then switches off automatically. the direction indicators are also used to signal that the commands sent by the remote control have been received and/or to signal a manoeuvre not carried out by the passenger compartment access control system.
The engagement of the direction indicators / hazard warning lights is managed by the BCM which also controls the flashing frequency which is sent to the other nodes via the CAN serial network.
In this way the two "direction indicator" warning lights in the instrument panel are also switched on; in addition, the system provides a low frequency acoustic signal in conjunction with the activation of the lights.
The direction indicators' check function checks that the lights are working correctly: the following are checked for each of the two circuits (right side branch and vehicle left side):
- open circuit or missing bulb;
- short circuit to ground (bulb or wiring to ground)
- short circuit to battery voltage (wiring short circuited to Vbatt).
When one of the situations described above is verified, the BCM makes the failure status available to the CAN: in the instrument panel: a special failure warning light comes on and, at the same time, the information is shown in the display only at key on. Simultaneously with the failure warning light switching on, the flashing frequency of the visual indication in the display and the acoustic signal increases; the flashing frequency of the exterior lights, on the other hand, remains unchanged.
There is a single ground signal sent by the steering column stalk to the BCM that manages the left and right direction indicators. The signal sent is coded by means of resistive dividers so that multiple information can be sent by the steering column stalk to the BCM via a single connection.
The ground signal activating the hazard warning lights from control button located in control panel.
The BCM receives a direct power supply from the battery through the line protected by a maxi fuse in the engine compartment junction unit.
The BCM receives an ignition-operated power supply (INT). This signal is used, amongst other things, to "wake up the network".
The BCM controls the door mirror direction indicators, the front direction indicators and the rear direction indicators.
The BCM is connected, via the CAN line, to the instrument panel to manage the direction indicator warning lights, the buzzer and, if there is a problem in the circuit, the "lights failure" warning light.