Electrical diagram of the model «280E» (engine 123.033) and «280CE» (engine 123.053) (Mercedes-Benz E-Class W123)

Contents: Legend of the basic electrical…↡ Connection points with the "mass" ↡ Schematic diagram of electrical…↡ Schematic diagram of electrical…↡

Electrical diagram of the model "280E" (engine 123.033, starting with chassis No.081 279) and "280CE" (engine 123.053, starting with chassis No.021 430).

Legend of the basic electrical circuit diagram of electrical equipment

№	Designation
1	Left headlight:
a	high beam thread
b	low beam thread
with	side/parking light lamp
d	fog light lamp
e	turn signal lamp
2	Brake Fluid Level Warning Light Sensor
3	Left front brake lining wear sensor
4	Right front brake lining wear sensor
5	Instrument cluster:
a	left turn signal indicator light
b	high beam indicator lamp
with	coolant temperature gauge
d	fuel gauge
e	fuel reserve indicator light
f	low battery indicator light
g	brake lining wear indicator light
h	brake fluid level and parking brake warning light
i	instrument lighting lamps
j	instrument lighting rheostat
k	emergency sound signaling device
l	right turn signal indicator lamp
m	electronic clock
6	Cigarette lighter with ashtray lamp
7	Radio*
8	Right headlight:
a	high beam thread
b	low beam thread
with	side/parking light lamp
d	fog light lamp
e	turn signal lamp
9	Fuel injection start mode switch
10	Starting fuel valve
11	Automatic antenna*
12	Parking brake indicator light switch
13	Coolant temperature sensor
14	Contact for switching on the emergency sound signaling device
15	Front ceiling light with switch
16	Ceiling light switch in the left door pillar
17	Ceiling light switch in the right door pillar
18	Two-tone sound signal (fanfare)
19	Speed controller sensor*
20	Speed controller amplifier*
21	Actuator of the software speed controller*
22	Alarm switch/relay interrupter
23	Glove compartment light switch
24	Glove compartment light
25	Fuse box
26	Heating element of the engine warm-up system
27	Fuel pump relay with electronic speed limiter of the engine warm-up system
28	Air conditioning compressor electromagnetic clutch
29	Relay I for switching on window lifters*
30	Relay II for switching on window lifters*
31	Door window switch
32	Speed Control Software Switch*:
A	off
V	slowdown/tuning
SP	return to previous speed of movement
IN	overclocking/tuning
33	Combined steering column switch:
a	turn signal switch
b	high beam headlight switch
with	headlight switch
d	windshield washer switch
e	windshield wiper speed switch
I	intermittent operation
II	low speed
III	high speed
34	Horn switch
35	Windshield wiper motor
36	Windscreen wiper intermittent relay
37	Ignition switch
38	Light switch
39	Sunroof Electric Motor*
40	Electric sunroof switch*
41	Automatic Transmission Solenoid Valve*
42	Foot switch for low gear engagement*
43	Starter interlock and reversing light switch*
44	Air Conditioning Compressor Emergency Pressure Sensor* (switching on at 2.6 kgf/cm², switching off at 2.0 kgf/cm²)
45	Air Conditioner Relay II*
46	Fan switch with light
47	Brake light switch
48	Windshield washer pump
49	Left headlight wiper motor*
50	Right headlight wiper motor*
51	Headlight Washer Relay*
52	Headlight washer pump*
53	Transistor ignition switch
54	Contactless ignition distributor
55	Spark plugs
56	Ignition coil
57	Lighting:
a	air flow direction knobs
b	heater control knobs
with	switch*
58	Throttle Position Control System Switching Valve
59	Thermoelectric switch (52°C) of the air conditioner dryer*
60	Thermoelectric switch (100°C)
61	Additional fan*
62	Additional fan relay*
63	Changeover valve for outside or recirculated air*
64	Air conditioner temperature sensor*
65	Air conditioner temperature selection switch*
66	Additional resistance of the fan motor
67	Fan motor
68	Additional resistance 0.6 Ohm
69	Left rear door window lift motor*
70	Left rear door window switch*
71	Power window switch block*:
a	left rear door window switch*
b	safety switch
with	left front door window switch
d	right front door window switch
e	right rear door window switch
72	Left front door window lift motor*
73	Additional resistance 0.4 Ohm
74	Rear window heating time relay*
75	Rear window defroster switch*
76	Gear selector lever lighting*
77	Starter
78	Battery
79	Generator with electronic voltage regulator
80	Ceiling light switch in left rear door pillar*
81	Rear courtesy light switch
82	Ceiling light switch in left rear door pillar*
83	Fuel pump
84	Rear lamp
85	Tail Light Wiring Harness Connector
86	Luggage compartment light
87	Fuel level indicator sensor
88	TDC sensor
89	Right front door window lift motor*
90	Diagnostic connector
91	Right rear door window lift motor*
92	Right rear door window switch*
93	Left rear light:
a	turn signal lamp
b	red/parking light lamp
with	reversing light bulb
d	brake light bulb
e	fog light lamp
94	License plate light
95	Rear window heating element*
96	Right rear light:
a	turn signal lamp
b	red/parking light lamp
with	reversing light bulb
d	brake light bulb

* Depending on the configuration.

** Latest modifications.

Connection points with the "mass"

№	Designation
M1	main connection point with the "mass" (behind the instrument cluster)
M2	front-right connection point with the "mass" (near the headlight)
M3	ground connection point on the left front wheel mudguard (for ignition coil)
M4	ground connection point of the front interior light
M5	"mass" of the engine
M6	ground connection point in the luggage compartment on the left wing mudguard
M7	ground connection point in the luggage compartment on the right wing mudguard