167548 - I23 LEFT/RIGHT MAIN BEAM HEADLAMP (ONE) DOES NOT COME ON OR COMES ON IRREGULARLY (IN ALL CONDITIONS)

One of the two main beam headlamps is not working or is working irregularly;

The main beam headlamps are controlled by the Body Computer Node via a relay located in the Engine Compartment Junction Unit.The main beam headlamp consists of a traditional bulb (known as the "auxiliary headlamp") and an electronic module connected in parallel to the bulb which supplies a coil which activates a partition which fully releases the xenon dipped headlamp.

STEP	OPERATIONS TO BE CARRIED OUT	TEST RESULTS
1	ELECTRICAL SYSTEM CHECK.	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the condition of the protective fuse in the engine compartment junction unit. (Wiring Diagram ) E2012 MAIN BEAMS	Move on to Step	Fuse blown	Replace the fuse (Wiring Diagram ) E2012 MAIN BEAMS
2	CHECK THE CONDITION OF THE AUXILIARY MAIN BEAM HEADLAMP BULB	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Extract the lamp from its housing and check the condition of the main beam headlamp bulb	Move on to Step	Bulb burnt out	Replace the bulb
3	LAMP ELECTRICAL SYSTEM CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the condition of the cables inside the lamp between: headlamp connector and main beam headlamp bulb xenon bulb shutter electronic module and connector	Move on to Step	Interruption or no insulation for the internal cables.	Restore the electrical connection, if necessary, replace the front headlamp [PR.5540B74]
4	ELECTRICAL SYSTEM CHECK.	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the continuity and the insulation of the wiring between the front lamp and the Engine Compartment Junction Unit (Wiring Diagram ) E2012 MAIN BEAMS	Move on to Step	Interruption or no insulation for the electrical connection	Restore the electrical connection (Wiring Diagram ) E2012 MAIN BEAMS
5	ELECTRICAL SYSTEM CHECK.	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the continuity and the insulation of the wiring between the outlet connector for the Engine Compartment Junction Unit and the Protective Fuse (Wiring Diagram ) E2012 MAIN BEAMS	Move on to Step	Interruption or no insulation for the Dashboard Junction Unit internal connection	Replace the engine compartment junction unit    See in Op. 5505A13 Additional junction unit in engine compartment - R.R.
6	CHECK ON CORRECT OPERATION	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the fault is no longer present