A3 Light module

Connector overview

Number	X-pin, color	Description
X12	15-pin, black	Connector A Light module
X38	15-pin, white	Connector B Light module
X10117	54-pin, black	Connector C Light module

Pin assignments at 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	RH front park light	Right headlight

4	A	Right fog light	Right fog light

5	A	Left license plate light	Left license plate light

6	A	Right front turn signal lamp	Right front turn signal lamp

7	M	Control module ground	Ground splice

8	A	Rear left turn light	Tail light I left

9	A	Left brake light	Tail light I left

10	A	Center brake light	High level stop light

11	A	Left low beam light	Left headlight

12	A	Right license plate light	Right license plate light

13	A	Right high beam light	Right headlight

14	A	Right front turn signal lamp	Right front auxiliary turn light

15	E	Terminal 30 voltage supply	Fuse F112

Pin assignments at connector X38

Pin	Type	Description / Signal type	Connection / Measuring notes
1	A	Nighttime illumination signal	Terminal 58g splice

2	M	Control module ground	Ground splice

3	A	Right low beam light	Right headlight

4	A	Left front turn signal lamp	Left front auxiliary turn light

5	A	Left tail light	Tail light I left

6	A	Left high beam light	Right headlight

7	A	Left fog light	Left fog light

8	E	Terminal 30	Fuse F113

9	A	Left back-up light	Tail light I left

10	A	Right back-up light	Tail light I right

11	A	Left front turn signal lamp	Left front turn signal lamp

12	A	LH rear turn light	Tail light I right

13	A	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 connector X10117

Pin	Type	Description / Signal type	Connection / Measuring notes
1	A	Illumination switch	Light switch

2	A	Engine ground LH adjustment	Left headlight

3	A	LH adjustment control	Left headlight

4	A	LH adjustment control	Left headlight

5	A	Engine ground LH adjustment	Left headlight

6	E	Seat belt signal	Driver's seat belt switch

7	E	Hazard lights ON signal	Hazard switch

8	E	Rear fog light ON signal	Fog light switch

9	E	Malfunction indicator lamp signal	Throttle position control module (EML) 750i

10	E	Washer fluid level	Washer fluid level switch

11		Not used

12	A	725tds Warning lamp preheating/diagnostic trouble code	DDE control module

13	E	Terminal R	Fuse F44

14	E	Right turn light signal	Combination switch

15	E	Oil level - thermal	Oil level sensor

16	E	Dimmer signal	Dimmer

17	A	Right tail light	Tail light I right

18	A	LH front park light	Left headlight Left front turn signal lamp US

19	A	Hazard switch illumination	Hazard switch

20	A	Engine ground RH adjustment	Left headlight

21	A	RH adjustment control	Left headlight

22	A	RH adjustment control	Left headlight

23	A	Engine ground RH adjustment	Left headlight

24	E	Engine coolant level	Engine coolant level switch

25	E	Brake light signal	Brake light switch

26	A	Acoustic signal	Chime module, Japan

27	A	Headlight widening control module power	Headlight widening control module

28		Not used

29		Not used

30		Not used

31	E	Terminal 15	Fuse F23

32	E	Left turn light signal	Combination switch

33	E	Headlights ON signal	Light switch

34	E	Signal Headlight widening adjustment	Headlight widening potentiometer

35	E	Trailer adapter module (AHM) signal line	Tail light I right

36	E	I-bus signal line	I-bus splice

37		Not used

38	E	Signal Navigation	Navigation control module

39	A	Rear-view mirror control	Electrochromic rear view mirror

40		Not used

41	E	Brake fluid level	Brake fluid level switch

42	E	Ignition key malfunction indicator (USA only)	Ignition switch

43	E	LH rear tweeter ground control	Combination switch

44	E	High beam ON signal	Combination switch

45	E	Rear fog light ON signal	Fog light switch

46		Not used

47		Not used

48		Not used

49	E	Catalytic converter overheated	Thermal control relay (Japan)

50		Not used

51	E	Park light ON signal	Light switch

52		Not used

53	E	Signal Headlight widening adjustment	Headlight widening potentiometer

54	A	Terminal 58 illumination	Electronic shock absorber control module (EDC)