A3 Light module

Connector overview

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

Pin assignments at connector X12

Pin	Type	Description / Signal type	Connection / Measuring notes
1	A	Right rear fog light	Trunk lid lamp, right Trailer module (AHM)

2	A	Left tail light	Trailer module (AHM)

3	A	Signal, side lights ON	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 light	Right headlight

7	M	Control module ground	Ground point

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 turn light	Right front auxiliary turn light

15	E	Terminal 30 voltage supply	Fuse F106

Pin assignments at connector X38

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

2	M	Control module ground	Ground splice

3	A	Right low beam light	Right headlight

4	A	Left turn light	Left front auxiliary turn light

5	A	Tail light signal Signal, brake power-dependent brake light function	Tail light I left

6	A	Left high beam light	Left headlight

7	A	Left fog light	Left fog light

8	E	Terminal 30 voltage supply	Fuse F61

9	A	Left back-up light	Trunk lid lamp, left

10	A	Right back-up light	Trunk lid lamp, right

11	A	Left front turn light	Left headlight

12	A	LH rear turn light	Tail light I right

13	A	Tail light signal Signal, brake power-dependent brake light function	Tail light I right

14	A	Right brake light	Tail light I right

15	A	Left rear fog light	Trunk lid lamp, left Trailer module (AHM)

Pin assignments at connector X10117

Pin	Type	Description / Signal type	Connection / Measuring notes
1	A	Illumination switch	S8 Light switch

2	A	Signal, headlight vertical aim control	Left headlight

3	A	Signal, headlight vertical aim control	Left headlight

4	A	Signal, headlight vertical aim control	Left headlight

5	A	Signal, headlight vertical aim control	Left headlight

6		Not used

7	E	Hazard lights ON signal	Hazard warning flasher switch

8	E	Rear fog light ON signal	S8 Light switch

9	A	Automatic headlight widening Supply, load/level sensor	Automatic headlight widening Front right level sensor

10	E	Washer fluid level	Washer fluid level switch

11		Not used

12	E	Automatic headlight widening Nominal value pick-up, load/level sensor	Automatic headlight widening Front right level sensor

13	E	Voltage supply terminal R	Fuse F9

14		Not used

15	E	Oil level - thermal	6-cylinder Oil level sensor

16	E	Dimmer signal	S8 Light switch

17	A	Right parking light	Trailer module (AHM) not USA

18	A	Signal, side lights ON	Left headlight

19	A	Hazard switch illumination	Hazard warning flasher switch

20	A	Signal, headlight vertical aim control	Right headlight

21	A	Signal, headlight vertical aim control	Right headlight

22	A	Signal, headlight vertical aim control	Right headlight

23	A	Signal, headlight vertical aim control	Right headlight

24	E	Engine coolant level	Engine coolant level switch

25	E	Brake light signal	Brake light switch

26	A	Back up signal	H10 Chime module

27	A	Actuation, bi-xenon shutter	Left headlight Right headlight

28	A	Back up signal	Intermittent wipe/wash control unit, rear

29	A	5 V signal, potentiometer 1	S8 Light switch

30	E	Signal Turn light	Combination switch

31	E	Terminal 15	Fuse F2

32		Not used

33	E	Headlights ON signal	Light switch

34	E	Signal Headlight widening adjustment	Light switch

35	E	Interface AHM/LM	Trailer module (AHM)

36	E/A	I/K-bus signal link	Connector, I/K-bus

37	M	Automatic headlight widening Supply, load/level sensor	Automatic headlight widening Rear right level sensor

38	E	Back up signal	Navigation control module

39	E	Back up signal	Electrochromic rear view mirror

40		Not used

41	E	Brake fluid level	Brake fluid level switch

42	A	Automatic headlight widening Supply, load/level sensor	Automatic headlight widening Rear right level sensor

43		Not used

44		Not used

45	E	Rear fog light ON signal	Light switch

46		Not used

47	E	ABS/DSC indicator lamp	A65 ABS/DSC control module

48		Not used

49	E	Automatic headlight widening Nominal value pick-up, load/level sensor	Automatic headlight widening Rear right level sensor

50	E	Signal High beam, headlight flash switch	Combination switch

51	E	Park light ON signal	Light switch

52	M	Ground for electronic components	Light switch

53	M	Automatic headlight widening Supply, load/level sensor	Automatic headlight widening Front right level sensor

54		Not used