The vehicle is equipped with two additional high beam rear fog lights located in the rear light clusters.The rear fog lamp is activated through a button in the exterior lights control unit; an LED at the back of the button comes on when the lights are switched on.The rear fog lamps are turned on by the body computer and the function is activated by:
an enablement signal with key on (INT);
a control signal from a switch on the exterior lighting control unit;
side light on signal.
headlamp signal (dipped or main beams), or fog lights on.
If one of the enablement signals fails, the activating button must be pressed again to switch on the rear fog lamp.The correct light operation is controlled by the Body Computer rear fog lights check function and a check is run under the following conditions:
open circuit (bulb missing or wiring broken) which can be diagnosed if there is no command
short-circuit to earth (bulb s.c. or wiring s.c. to earth)
short circuit to battery voltage (wiring short circuited to Vbatt)
replacement of 21W bulb with a 5W bulb
When one of the situations described above is ascertained, the Body Computer makes the failure status available to the CAN: fault information is displayed on the instrument panel.