A3 Light module

Plug connector overview

Number	X-pin, colour	Description
X12	15-pin, black	Plug connector A Light module
X38	15-pin, white	Plug connector B Light module
X10117	54-pin, black	Plug connector C Light module

Pin assignments at plug connector X12

Pin	Type	Description / Signal type	Connection / Measuring notes
1	A	Right rear fog light	Tail light I right

2	A	Left tail light	Tail light I left

3	A	Front right parking light	Right headlight

4	A	Right fog light	Right fog light

5	A	Left licence plate light	Left licence plate light

6	A	Right front turn signal indicator	Right front turn signal indicator

7	M	Control unit ground	Ground connector

8	A	Rear left turn signal indicator	Tail light I left

9	A	Left brake light	Tail light I left

10	A	Centre brake light	Raised brake light

11	A	Left low beam light	Left headlight

12	A	Right licence plate light	Right licence plate light

13	A	Engine running	Right headlight

14	A	Right front turn signal indicator	Front right auxiliary flasher unit

15	E	Voltage supply terminal 30	Fuse F112

Pin assignments at plug connector X38

Pin	Type	Description / Signal type	Connection / Measuring notes
1	A	Night light signal	Connector, terminal 58g

2	M	Control unit ground	Ground point

3	A	Right low beam light	Right headlight

4	A	Left front turn signal indicator	Front left auxiliary flasher unit

5	A	Inner left tail light	Tail light I left

6	A	Left high beam light	Left headlight

7	A	Left fog light	Left fog light

8	E	Voltage supply terminal 30	Solenoid valve MV1

9	A	Left reversing light	Tail light I left

10	A	Right reversing light	Tail light I right

11	A	Left front turn signal indicator	Left front turn signal indicator

12	A	Rear left turn signal indicator	Tail light I right

13	A	Inner right tail light	Tail light I right

14	A	Right brake light	Tail light I right

15	A	Left rear fog light	Tail light I left

Pin assignments at plug connector X10117

Pin	Type	Description / Signal type	Connection / Measuring notes
1	A	Lighting, light switch	Light switch

2		Not used

3		Not used

4		Not used

5		Not used

6	E	Belt signal	Driver's seat belt buckle switch

7	E	Signal, hazard warning lights ON	Hazard warning flasher switch

8	E	Signal, rear fog light ON	Fog light switch

9	E	Warning lamp signal	EML control unit 750i

10	E	Wash water level	Wash water level switch

11		Not used

12	A	Warning lamp preheating/error signal 725tds	DDE control unit

13	E	Voltage supply terminal R	Fuse F44

14	E	Signal, right turn signal indicator	Turn indicator/low beam selector

15	E	Oil level - thermal	Oil level sensor

16	E	Signal, night light dimmer	Dimmer

17	A	Inner right tail light	Tail light I right

18	A	Front left parking light	Left headlight

19	A	Lights, hazard warning switch	Hazard warning flasher switch

20		Not used

21		Not used

22		Not used

23		Not used

24	E	Coolant level	Coolant level switch

25	E	Brake light signal	Brake light switch

26	A	Acoustic signal	Gong, Japan

27	A	Supply for beam throw control unit (LWR)	Beam throw adjustment control unit (LWR)

28		Not used

29		Not used

30		Not used

31	E	Voltage supply, terminal 15	Fuse F23

32	E	Signal, left turn signal indicator	Turn indicator/low beam selector

33	E	Headlights ON signal	Light switch

34		Not used

35	E	AHM signal line	Trailer module (AHM)

36	E	I-bus signal line	I-bus connector

37		Not used

38	E	Signal Navigation	Navigation control unit

39	A	Activation, interior rear-view mirror	Electrochromic interior rear view mirror

40		Not used

41	E	Brake fluid level	Brake fluid level switch

42		Not used

43	E	Signal, low beam headlight ON	Turn indicator/low beam selector

44	E	Signal, high beam ON	Turn indicator/low beam selector

45	E	Signal, rear fog light ON	Fog light switch

46		Not used

47		Not used

48		Not used

49	E	Catalytic converter overheated	Thermal switch (LA Japan)

50		Not used

51	E	Signal, parking light ON	Light switch

52		Not used

53		Not used

54	A	Right high beam light	EDC control unit