Detailed description

Detailed description

General

The courtesy lamps are activated by the respective door module via bus messages from BCM (Body Control Module). Luggage compartment lighting is activated from the Rear Electrical Centre (REC) also via a bus message from BCM. All other lamps receive their power supply from a relay activated by BCM. The lamps are grounded with PWM (pulse width modulation) from BCM or receive a direct ground from the body via a button or switch.

All interior lighting, including courtesy lights and luggage compartment lights, go off automatically after 20 minutes unless the ignition is turned on. BCM activates the relay and sends the bus message that the luggage compartment lighting and courtesy lights should be turned off.

Lamps are turned on by buttons when the relay is not activated, e.g. if you remain in the car for 20 minutes without the ignition on. In this situation, if you press a button to turn on the roof light or a reading light, open the glovebox or turn on the vanity mirror lamp, BCM will activate the interior lighting relay for a further 20 minutes. The lead from the relay passes through BCM en route to the lamps. BCM applies a voltage and measures the lead to assess whether the circuit is grounded by a button or switch when the relay is not activated.

Note that BCM only detects a voltage drop when a button suddenly grounds the circuit. BCM cannot detect whether the interior lighting has been activated e.g. by the glovebox being already open.

The car interior lighting consists of the following:

Roof lamps and floor lighting

Two roof light fittings have lamps to give a general light in the cab. The roof lamps and floor lamp in the car are turned on manually or automatically (doors control on/off). The interior lighting switch (53) has the following positions:

1 - Interior lighting off.

0 - Doors control lighting on/off (automatic).

2 - Interior lighting on.



When the button is in position 2 (on) the lamps in the front and rear fittings are grounded directly. In position 1 (off) the circuit to ground is open. In position 0 (automatic) the lamps are grounded with PWM from BCM via REC. Pulse width modulation allows light intensity to be turned up or down smoothly.

The PWM output from BCM is controlled as follows:

-	Interior lighting comes on for 20 s when "unlock" on the remote control is pressed.

-	Pressing "lock" or locking with a key turns off the light directly.

-	Interior lighting comes on when a door is opened and stays on 20 s after all doors have been closed. The lamps go out when the ignition is switched on. If a door is opened when the ignition is on, the lighting will come on and remain lit until the door is closed.

-	When the key is removed from the ignition lock, the lights come on and remain on for 20 s.

Reading lights

Two lamps in the front and two in the rear, fitted in the roof. Manually operated with the switch next to each lamp. The lamps receive direct chassis ground when switched on. Power is supplied from the interior lighting relay.

Vanity mirror lighting

Lamps in the sun visor at the vanity mirror. Lights when the mirror cover is opened.

The lamps are directly body-grounded when the mirror cover is opened. The supply comes from the interior lighting relay.

Glove box light

Glove box lighting comes on when the glovebox is opened.

The lamp is chassis grounded directly when the glove box is opened. The power comes from the interior lighting relay.

Floor lighting

The floor lighting gives indirect light in the front footwell on the left and right sides. Comes on when any door is opened.

The lamps are grounded with PWM (pulse width modulation) from BCM. The supply comes from the interior lighting relay. The lamps follow the logic of the roof lights when set to automatic (door).

Courtesy lights

Courtesy lighting in the lower edges of the front doors illuminates the ground below the door during entry

BCM detects the door switch position via leads. BCM sends a bus message with the position of the door switches. The bus message is used by the front door modules which turn the lamps on when any front door is opened.

Luggage compartment lighting

Luggage compartment lighting illuminates the luggage space and parts of the ground outside.

BCM detects the door switch position via leads. BCM sends a bus message with the position of the door switch. The bus message is used by REC which turns the lamp on when the boot lid is opened.