Anyone hosting Supplement 14?

SUPPLEMENT 14 - W124 WIRING DIAGRAMS

INDEX
MODEL .................SALES DESIGNATION
124.026 ................... 260E
................................ 300E 2.6(*)
124.030 ................... 300E
124.034 ................... 400E
124.036 ................... 500E
124.050 ................... 300CE
124.051 ................... 300CE
124.090 ................... 300TE
124.128 ....................300D 2.5 Turbo
124.133 ................... 300D Turbo
124.193 ………............ 300TD Turbo
124.230 ................... 300E 4MATIC
124.290 ................... 300TE 4MATIC
REVISIONS: (*) As OF My 1990

INDEX....................101
WIRING DIAGRAM SYSTEM
HOW TO USE THIS MANUAL....Supplement 11

CIRCUIT......................................PAGE
Active Bass: Amplifiers and Speakers 132 132/1
Anti-Lock Brake System (ABS) 150 150-1 150-2 150-3
Anti-Theft Alarm System 163-5
ABS with ASD/4matic 151 151-1
ABS with ASR 152 152-1 152-2 152-3
ABS with ASR/Electronic Accelerator152-4 152-5
Automatic Antenna 131 131-1 131-2 131-3 131-4
Automatic Climate Control 301 This has its on section further down this thread
Automatic Locking Differential (ASD) 153
Auxiliary Fan 121 121-1 121-2 121-3 121-4 121-5
CD Changer 131-7 131/8
Cellular Telephone 134
Central Locking System 146 146-1 146-2 146-3 146-4
Charging System 123 123-1
Cigar Lighter 131 131-1
Clock 136
Component Locations 201 These comprise an entire section of this thread
Controller Area Network (CAN) Data Bus 122
Cruise Control 137 137-1 137-2 137-3 137-4
Diagnostic Module 113/6
Diagnostic Socket 113 113-2 113-3 113-4 113-5
Electronic Accelerator System 138 138-1 138-2 138-3
Electronic Diesel System 115 115-1 116 116-1 116-2
Electronic Engine Controls 117 117-1 118 118-1 119 119-1 120 120-1 120-2 120-3 120-4
Engine Overload Protection 121 121-1 121-2

SUPPLEMENT 14 - W124 WIRING DIAGRAMS - continued

4MATIC System 154 154-1
First Gear Start 164
Fuel Delivery 114 114-1 114-2 114-3 114-4 114-5
Fuse Block Details 108 108-1 108-2 109 109-1 109-2 110 110-1 110-2
Fuse Circuit List 103 104
Fuse/Relay Box 102
Gauges 136 136-1 136-2 136-3 136-4 136-5 136-6 136-7 136-8
Ground Distribution 165 165-1 165-2 165-3 165-4 165-5
Headlamp Wiper/Washer 162 162-1
Heated Seats 142 142-1 142-2
Heated Windshield Washer System 162
Horns 145
Ignition 113 113-1 113-2 113-3 113-4 113-5 113-6

SUPPLEMENT 14 - W124 WIRING DIAGRAMS - continued

Lamps:
-Backup 125
-Center Console 130 130-1 130-2 130-3 130-4 130-5 130-6
-Courtesy 128 128-1 128-2 128-3 128-4 128-5 128-6 128-7 128-8 128-9
-Fog 124 124-1
-Glove Box 131 131-1
-Hazard 127
-Headlamps 124 124-1
-Instrument Cluster 130 130-1 130-2 130-3 130-4 130-5 130-6
-License 126 126-1
-Park 126 126-1
-Reading 129
-Side Marker 126 126-1
-Stop 125
-Tail 126 126-1
-Turn Signal 127
-Trunk 128 128-1 128-2 128-3 128-4 128-5 128-6 128-7 128-8 128-9
-Vanity 129 129-1 129-2 129-3 129-4

SUPPLEMENT 14 - W124 WIRING DIAGRAMS - continued

Orthopedic Seats 155
Outside Heated Mirrors 149
Power Distribution 105 105-1 106 107
Power Seats 148 148-1 148-2 148-3 148-4 148-5 148-6 148-7 148-8 148-9
Power Windows 144 144-1 144-2 144-3 144-4 144-5
Preglow System 112 112-1
Radio 131 131-1 131-2 131-3 131-4
Rear Defogger 141
Rear Head Restraint System 139
Rear Window Sun Shade 143
Rear Wiper/Washer 161
Seat Backrest Locking System 156
Seat Belt Extenders 157 157-1 157-2 157-3
Sliding Roof 140
Sound System: Amplifiers and Speakers 133 133-1
Start 111 111-1 111-2
Supplemental Restraint System (SRS) 158 158-1 158-2 158-3
Tachometer 136
Tailgate Closing Assist 129-2 129-4
Telescopic Steering Column 147 147-1
Transmission Shift Point Delay 120-3
Transmission Shift Point Relay 120-2
Transmission Kick-down 113 113-1
Two-Piece Radio with Sound System 131-5 131-6 131-7 131-8
Warning Indicators 136 136-1 136-2 136-3 136-4 136-5 136-6 136-7 136-8
Warning System 135 135-1 135-2 135-3 135-4
Wiper/Washer 159
Wire and Plug Connection Locations


Component Files - 1st 10 - (Identified below and hyperlinked to these files)

SUPPLEMENT 14 - W124 COMPONENTS

Click the link to see the component image in acrobat:

Not all components in Supplement 14 have a figure and a few in the X's & Z’s do not have a location either. If it does have a figure then it will show as the number at the end of the component line and should be hyperlinked. Please let me know of any errors.

INDEX
MODEL .................SALES DESIGNATION
124.026 ................... 260E
................................ 300E 2.6*
124.030 ................... 300E
124.034 ................... 400E
124.036 ................... 500E
124.050 ................... 300CE
124.051 ................... 300CE
124.090 ................... 300TE
124.128 ....................300D 2.5 Turbo
124.133 ................... 300D Turbo
124.193 ………............ 300TD Turbo
124.230 ................... 300E 4MATIC
124.290 ................... 300TE 4MATIC
* REVISIONS: As OF My 1990



Component.....Component Designation......Location...........Page - Figure

A1 Instrument cluster Left side of dashboard, forward of steering wheel
A2 Radio Center console
A2/1 Line-out unit (Sound System) MY 1990 with Sound System: back of radio chassis As of MY 1991: on top of Tuner/amplifier (A2/3)
A2/3 Tuner and amplifier (trunk) Right side of trunk
A2/4 Radio control unit Center console
A2/6 CD changer (in trunk) Right wheel well (6 cylinder) Under hatshelf (8 cylinder)
A7 ABS hydraulic unit Left front corner of engine compartment 231-2

A7/2 4MATIC hydraulic unit Left front corner of engine compartment
A7/3 ABS/ASR hydraulic unit Left front corner of engine compartment 252-4

A9 A/C compressor Lower left front of engine
A9k1 Electromagnetic clutch part of A9 230-4
A9l1 RPM sensor part of A9 230-4
A10 Left seat belt extender Behind left B-pillar 246-5
A11 Right seat belt extender Behind right B-pillar
A12 Tailgate closing assist Center of tailgate, behind panel 243-5
A12s1 Tailgate closing assist switch part of A12
A12s2 Tailgate lock switch part of A12
A16 Knock sensors On left side of engine block 250-4
A16g1 Knock sensor 1 (left side of engine) On engine block beneath intake manifold near cylinder #2
A16g2 Knock sensor 2 (right side of engine) On engine block beneath intake manifold near cylinder #5
A28/1 Antenna splitter On antenna mast 255-1
A34 Telephone handset Center console
A35 Transmit/receive unit (TRU) Sedan/Coupe: Left trunk well Wagon: Right cargo area 254-5
A35/3 In-dash control unit Front of Dome lamp (E15) 254-4
B2 Air flow sensor position indicator part of B2/1, front of airflow sensor housing 232-1
B2/1 Air flow sensor with intake air temperature sensor (EDS) Top of engine, behind right headlamp 249-1
B2/2 Air mass sensor with hot-wire Top of engine, on intake manifold 249-2
B4 Fuel level sensor Top of fuel tank 238-6
B5 Oil pressure sensor At base of oil filter housing 237-6
B5/1 Pressure sensor (EDS) On component compartment wall, forward of battery 247-3
B6 Hall-effect speed sensor Rear of instrument cluster, behind speedometer 233-1
B10/1 Heater core temperature sensor Center of dashboard, below radio 240-3
B10/4 In-car temperature sensor Center of windshield header, part of dome lamp 235-1
B10/5 Outside temperature sensor Right side of component compartment 232-3
B10/6 Evaporator temperature sensor Right side of steering column 233-6
B10/8 Coolant temperature sensor (climate control) On cylinder head 245-4
B11/2 Coolant temperature sensor (EZL/CIS-E, LH)(4-pole) Top rear of cylinder head (6 cylinder)230-3Top front of engine (8 cylinder)249-2
B11/4 Coolant temperature sensor (EDS) Top left side of engine, on coolant elbow248-2
B11/7 Preglow system temperature sensor Top center of engine (MY 1987) Right front of engine, near thermostat housing in coolant pump outlet (As of MY 1990)247-6
B13 Coolant temperature gauge sensor Left side of engine, above intake manifold230-3
B14 Outside temperature sensor (outside temperature indicator) Left front corner of front bumper 238-4
B17/2 Intake air temperature sensor (CIS-E) On air filter housing
B17/7 Intake air temperature sensor Front of engine, behind radiator 248-3
B18 Altitude correction capsule Right side of component compartment 229-4
C1 SRS energy accumulator Front passenger tootwell, behind right kick panel 244-3
C2 Electrolytic capacitor Right side of component compartment 253-6
E1 Left headlamp unit left front ot vehicle
E2 Right headlamp unit Right front of vehicle
E3 Left taillamp unit Left rear of vehicle
E4 Right taillamp unit Right rear of vehicle
E10/1 Center air outlet illumination Center dashboard
E10/2 Left air outlet illumination Left side of dashboard
E10/3 Right air outlet illumination Right side of dashboard
E11/1 Left rear reading lamp Left C-pillar
E11/2 Right rear reading lamp Right C-pillar
E12 Shift pattern illumination Center console, below shift lever
E13/2 Glove box lamp with switch Top left of inside of glove box
E14/1 Left sun visor with illuminated vanity mirror part of sun visor
E14/2 Right sun visor with illuminated vanity mirror part of sun visor
E15/2 Front dome lamp with shutoff delay and reading lamp Center of windshield header
E15/3 Rear dome lamp Center of rear windshield header
E15/4 Dome/reading lamp with seat belt reminder lamp Center of windshield header
E17/3 Left front entrance/exit lamp Lower rear of left front door
E17/4 Right front entrance/exit lamp Lower rear of right front door
E17/5 Left rear entrance/exit lamp Lower rear of left rear door
E17/6 Right rear entrance/exit lamp Lower rear of right rear door
E18/1 Trunk lamp Inside of trunk
E19/1 Left license plate lamp Below left side of trunk lid lift handle
E19/2 Right license plate lamp Below right side of trunk lid lift handle
E20 Exterior lamp switch illumination Beneath exterior lamp switch
E21 Center high mounted stop lamp Center of rear hatshelf (sedan) Attached to tailgate (wagon)
E25/1 Left C-pillar interior lamp In left C-pillar
E25/2 Right C-pillar interior lamp In right C-pillar





Component Files - 2nd 10

SUPPLEMENT 14 - W124 COMPONENTS - continued

Component......Component Designation...Location...............Page - Figure

E25/3 Left D-pillar interior lamp In left D-pillar
E25/4 Right D-pillar interior lamp In right D-pillar
F1 Fuse and relay box Left side of component compartment 231-4
F2 Maxi-fuse box In F1
F13 Auxiliary fuse holder, power seats Part of F1 (fuses E, F, G and H)
F14 Auxiliary fuse holder, anti-theft alarm Flear of fuse box, position E
F15 Auxiliary fuse holder, blower motor/ACC/Tempmatic Left side of component compartment 245-5
F22/1 Auxiliary fuse holder, heated seats Left rear of engine compartment
F22/2 Auxiliary fuse holder, telephone, terminal 30 In engine compartment, next to fuse/Relay box (F1) 254-6
F23 Module box Right side of component compartment 253-5
G1 Battery Right side of component compartment
G2 Alternator Lower right front of engine 229-6
G3/2 Heated O2-sensor In exhaust pipe, rear of transmission 237-5
G3/2x1 Connector, O2-sensor heater coil (2-pole) Left side of front passenger footwell 233-4
G3/2x2 Connector, O2-sensor signal (1-pole) Left side of front passenger footwell 233-4
H1 Two-tone horn Front of radiator 232-2
H3 Alarm horn Left side of engine compartment 231-1
H4/5 Left door speaker Driver’s door panel
H4/6 Right door speaker Front passenger door panel
H4/7 Left rear speaker Left rear of hatshelf
H4/8 Right rear speaker Right rear of hatshelf
H4/9 Left front speaker Left top corner of dahboard
H4/10 Right front speaker Right top corner of dashboard
K1 Overvoltage protection relay (5-pole) Right side of component compartment, behind battery 239-3
K1/1 Overvoltage protection relay, 87E (7-pole) Right side of component compartment, behind battery 239-3
K1/2 Overvoltage protection relay, 87E/87L/30a (9-pole) Right side of component compartment, behind battery: Gasoline 252-5
K1/2 Overvoltage protection relay, 87E/87L/30a (9-pole) Right side of component compartment, behind battery: Diesel 252-1
K2 Headlamp washer relay Rear of fuse box, location D
K4 Power window relay Rear of fuse box, location F 231-5
K5 Power seat relay Rear of fuse box, location A
K9 Auxiliary fan relay Rear of fuse box, location C 231-5
K10 Auxiliary fan preresistor relay Rear of fuse box, location B
K11/1 Left head restraint adjustment relay Under left front seat
K11/2 Right head restraint adjustment relay Under right front seat 236-5
K12/1 Cruise control/engine overload protection relay Right side of component compatment, near K1/1 251-5
K17 Air injection relay Fuse/Relay box, position E
K18 Seat belt warning relay Left side of driver’s footwell
K24 Convenience relay Rear of fuse box, location F




Component Files - 3rd and last set of Component Files, 27 in all.

SUPPLEMENT 14 - W124 COMPONENTS - continued

Component......Component Designation...Location...............Page - Figure

K27 Fuel pumps relay Beneath right side of rear seat 248-4
K29 Transmission upshift delay relay Right side of component compartment, near K1/1 249-6
K29/1 First gear start relay Fuse/Relay box, position G
K31 4MATIC funtion/test relay Passenger footwell, behind kick panel
L1 TDC sensor Front left of engine 239-5
L2 Inductive speed sensor, transmission Left side of transmission 253-4
L3 Starter ring gear speed sensor Lower left side of bell housing
L5 Crankshaft position sensor Top of bell housing, behind oil filter 249-3
L5/1 Camshaft position sensor On intake camshaft front cover 250-6
L5/1 Camshaft position sensor Top left front of engine (8 cylinder) 249-2
L6 Rear axle speed sensor Front of rear differential 237-3
L6/1 Left front wheel speed sensor Left front steering knuckle 238-3
L6/2 Right front wheel speed sensor Right front steering knuckle
L7 Fuel rack position sensor Lower left side of engine 247-2
M1 Starter Lower left rear of engine, below oil filter
M2 Blower motor Center front of cowl, behind panel 232-3
M2/2 Module box blower motor Right side of component compartment, behind Module box 253-5
M3/1 Fuel pump 1 Forward of rear axle 238-5
M3/2 Fuel pump 2 Forward of rear axle 238-5
M4 Auxiliary fan Front of radiator 232-2
M4m1 Left auxiliary fan Front of radiator 255-3
M4m2 Right auxiliary fan Front of radiator 255-3
M5/1 Windshield washer pump Front of windshield washer fluid reservoir 230-2
M5/2 Headlamp washer pump Front of windshield washer fluid reservoir 230-2
M5/3 Rear window washer pump Behind right rear quarter panel (wagon) 242-4
M6/1 Wiper motor Center front of cowl, behind panel 232-3
M6/2 Left headlamp wiper motor Left front of engine compartment 230-5
M6/3 Right headlamp wiper motor Right front of engine Compartment 230-1
M6/4 Rear window wiper motor Center of tailgate, behind panel (wagon) 243-5
M9 Aspirator blower, in-car temperature sensor Top of passenger footwell, behind dashboard
M10/3 Left front power window motor Left front door 240-6
M10/4 Right front power window motor Right front door
M10/5 Left rear power window motor Left rear door
M10/6 Right rear power window motor Right rear door
M11 Automatic antenna Left side of trunk (sedan) 232-5
M11 Automatic antenna Right rear quarter panel (wagon) 242-3
M12 Sliding/pop-up roof drive unit Left front corner of trunk (sedan) 232-5
M12 Sliding/pop-up roof drive unit Left rear quaner panel (wagon) 242-1
M13 Coolant pump Right side of engine compartment
M14/1, M14/2 Supply pump, central locking system Below right side of rear seat 233-3
M15 ASR charging pump On brake booster, below master cylinder 253-1
M16 Cruise control actuator Lower left side of engine 238-2
M16/1 Electronic accelerator/cruise control/idle speed control actuator Lower left side of engine
M20 Adjustable steering column motor Left side of steering column 233-6
M21/2 Electrically adjustable and heated front passenger rearview mirror In right side rearview mirror
M24 Rear window sun shade motor Under rear hatshelf, in trunk 245-6
M25 Left front power seat motor group Under left front seat 232-6
M26 Right front power seat motor group Under right front seat 236-5

SUPPLEMENT 14 - W124 COMPONENTS - continued

Component......Component Designation...Location...............Page - Figure

N1/2 Electronic ignition control unit (EZL) Left side of engine compartment, on fender 251-1
N1/3 EZL/AKR ignition control unit Left side of engine compartment, on fender 251-1
N2/2 SRS control unit Top of transmission tunnel, behind front console 240-2
N2/4 Warning module (seat belts, keys, lights) Behind right side of instrument cluster 240-4
N3 CIS-E control unit Right side of component compartment, behind battery 229-3
N3/1 LH control unit Right side of component compartment, in Module box 250-1
N4 Cruise control amplifier Behind lower left side of dashboard 234-3
N4/1 Electronic accelerator/cruise control/idle speed control unit Right side of component compartment behind battery (6 cylinder) 252-5
N4/1 Electronic accelerator/cruise control/idle speed control unit Right side of component compartment behind battery (8 cylinder) 250-1
N4/3 Cruise control/idle speed control unit Right side of component compartment in Module box
N6 A/C compressor control unit Right side of component compartment behind battery 239-3
N7 Exterior lamp failure monitoring unit Rear of fuse box, position K
N10 Combination relay (turn/hazard signal, heated rear window, wiper motor) Rear of fuse box, position H
N13 Rear window intermittent wiper timer Left corner of tailgate, behind panel (wagon) 241-5
N14 Preglow time-limit relay Left side of engine compartment, on inner fender
N16 Engine systems control unit (MAS) Right side of component compartment, behind battery 255-2
N16/1 Base module Right side of component compartment, in Module box 250-1
N16/3 Fuel pump relay Right side of component compartment, behind battery 229-3
N16/4 Fuel pump,relay with kickdown cut-out Right side of component compartment, behind battery 229-3
N22 ACC pushbutton control unit Center console, above radio
N24 SRS voltage converter Front passenger footwell, behind right kickpanel 240-1
N25/1 Left front seat heater relay Beneath carpeting, forward of left front seat 239-2
N25/2 Right front seat heater relay Beneath carpeting, forward of right front seat
N25/5 Front seat heater control unit Under left side of rear seat 246-1
N28 Anti-theft alarm control unit Behind front passenger footrest 240-1
N27 Anti-towing sensor Below left side of rear seat (M.Y. 1986 Only) 233-2
N30 ABS control unit Right side of component compartment: behind battery (6 cylinder) in Module box (8 cylinder) 239-3
N30/1 ABS/ASB control unit Right side of component compartment: behind battery(6 cylinder) 252-5
N30/1 ABS/ASB control unit Right side of component compartment: in Module box (8 cylinder) 250-1
N30/2 ASD control unit Right side of component compartment, behind battery 252-1
N30/3 4MATIC control unit Right side of component compartment, forward of ABS control unit (N3)
N32/1 Left front power seat control unit (with memory) Under left front seat
N32/3 Left front power seat control unit (with memory and steering column adjustment) Under left front seat 232-6
N35 Daytime running lamp control unit Behind front passenger footrest 254-1
N39 EDS control unit Right side of component compartment, behind battery 247-5
N40 Audio power amplifier (circuit 58D) Behind instrument cluster, on steering column 240-4
N40/1 Audio power amplifier, left speakers Right side of trunk - (Sedan) 254-1
N40/1 Audio power amplifier, left speakers Right side of trunk - (Coupe) 247-5
N40/2 Audio power amplifier, right speakers Right side of trunk (Sedan) 254-2
N40/2 Audio power amplifier, right speakers Right side of trunk (Coupe) 254-3
N40/3 Audio power amplifier, left/right speakers Right side of trunk
N42 Left seat belt extender control unit Behind left rear interior panel 246-6
N43 Right seat belt extender control unit Behind right rear interior panel
N49 Steering angle sensor Plastic slip ring on steering column, behind steering wheel
N57 Convenience control unit: ATA, central locking system, power windows, sliding/pop-up roof Beneath left side of rear seat
N59 Diagnostic module, California version (engines 104/119 and engine 120 Federal/California) Right front footwell, next to N26
R1 Heated rear window element Part of rear windshield
R2/2 Left heated windshield washer nozzle Part ot left windshield washer nozzle 232-4
R2/3 Right heated windshield washer nozzle Part of right windshield washer nozzle
R2/4 Left heated washer nozzle hose Under left side of engine hood 246-4
R2/5 Right heated washer nozzle hose Under right side of engine hood 246-4
R2/6 Heated check valve Under left side of engine hood 246-4
R2/7 Heated windshield washer pump hose Clipped to right engine hood hinge 246-4
R3 Illuminated cigar lighter Center console, in ashtray
R9 Glow plugs Top ot engine, at each cylinder intake
R11 Driver-side heated mirror Part of driver’s mirror 235-2
R12/1 Left front emergency tensioning retractor (ETR) squib In base of left B-pillar, part of ETR
R12/2 Right front emergency tensioning retractor (ETR) squib In base of right B-pillar, part of ETR 236-2
R12/3 Driver airbag squib Center of steering wheel, beneath airbag 236-1
R12/4 Front passenger airbag squib 1 Right side of dashboard, behind airbag 247-1
R12/5 Front passenger airbag squib 2 Right side of dashboard, behind airbag 247-1
R13/1 Left front seat cushion heater element In left front seat
R13/2 Left front backrest heater element In left front seat backrest
R13/3 Right front seat cushion heater element In right front seat
R13/4 Right front backrest heater element In right front seat backrest
R15 Auxiliary fan preresistor Lower left front corner of engine compartment 231-2
R16/1 Reference resistor (EZL) Left side of component compartment 231-3
R16/2 Reference resistor (EZL/AKR) Round plug on N1/3
R17/1 Reference resistor (CIS-E) Right side of component compartment in front of cowl 229-4
R18/1 Resistance trimming plug, electronic idle speed control (ELR) Left side of component compartment, in front of brake fluid reservoir 243-3
R18/2 Reference resistor (EGR) Right side of component compartment, behind battery
R25 Accelerator pedal position sensor Top left side of engine. beneath accelerator linkage 251-6
R26 Fader switch Center console, rear of transmission shift lever

SUPPLEMENT 14 - W124 COMPONENTS - continued

Component...Component Designation...Location...............Page - Figure

S1 Exterior lamp switch Left side of dashboard, left of steering column 234-3
S2/1 Ignition/starter switch Left side of dashboard, right of steering column 234-1
S2/2 Glow/starter switch Left side of dashboard, right of steering g column 234-1
S4 combination switch Left side of steering column
S4s6 Horn contact Center of steering wheel, beneath airbag
S5/3 High-voltage distributor Top front of engine 229-6
S5/5 Left high-voltage distributor Top left front of engine 250-5
S5/6 Right high-voltage distributor Top right front of engine 250-5
S6 Hazard flasher switch Center console, above radio
S7/3 4MATIC function/test selection switch Right side of component compartment 251-3
S8/1 Warning buzzer contact, exterior lamps Part of S2/1, S2/2 234-1
S8/2 Warning buzzer contact, exterior lamps/central locking system Part of S2/1, S2/2 234-1
S9 Stop lamp switch Top of brake pedal, on bracket 240-5
S9/1 Stop lamp switch (4MATIC/ASD) Top of brake pedal, on bracket
S10/1 Left front brake pad wear sensor In left front brake pad
S10/2 Right front brake pad wear sensor In right front brake pad
S10/3 Left rear brake pad wear sensor In left rear brake pad
S10/4 Right rear brake pad wear sensor In right rear brake pad
S11 Brake fluid level switch Left side of component compartment, top of brake fluid reservoir 231-3
S12 Parking brake switch Driver‘s footwell, at left kickpanel 234-4
S13/2 Sliding/pop-up roof switch Center of windshield header, part of E15/2
S14 Heated rear window switch Center console, above radio
S16/1 Starter lock-out/backup lamp switch Left side of transmission 238-1
S16/2 Backup lamp switch Left side of transmission 244-2
S16/3 Starter lock-out/backup lamp switch, selector lever position recognition
S16/6 Kickdown switch Under top of accelerator pedal 239-1
S16/7 Kickdown switch/transmission mode Under top of accelerator pedal
S16/8 “B” engagement switch
S17/1 Left door switch In left front door iamb 235-4
S17/2 Right door switch In right front door jamb
S17/3 Left front door switch In left front door jamb 235-4
S17/4 Right front door switch In right front door jamb
S17/5 Left rear door switch In left rear door jamb
S17/6 Right rear door switch In right rear door jamb
S17/7 Left door switch (power seat relay) In left front door jamb 235-4
S17/8 Trunk lamp switch Left underside of trunk lid 235-6
S17/10 Right door switch (power seat relay) In right front door jamb
S17/11 Left door switch (seat belt extender, entrance/exit lamp) In left door jamb (coupe)
S17/12 Right door switch (seat belt extender, entrance/exit lamp) In right door jamb (coupe)
S18 Rear dome lamp switch Center console, above radio
S18/1 Rear dome lamp switch with illumination Center console, above radio
S19s1 Right front power window switch Center console
S19s2 Right rear power window switch Center console
S20s1 Left front power window switch Center console
S20s2 Left rear power window switch Center console
S21/1 Left front power window switch Center console
S21/2 Right front power window switch Center console
S21/3 Left rear power window switch Left rear door
S21/4 Right rear power window switch Right rear door
S21/5 Left rear power window switch (front console) Center console
S21/6 Right rear power window switch (front console) Center console
S21/7 Center console safety switch, rear power windows Center console
S22 Left front power seat switch Left front door
S23 Right front power seat switch Right front door
S24 Fresh/recirculated air switch Center console, above radio
S25/5 105/115 “C Temperature switch auxiliary fan high speed/emergency cut-out Top left side of engine 230-3
S25/6 50 °C Temperature switch Lower left rear of engine
S26/1 Heated windshield washer system thermoswitch Under left rear corner of engine hood 246-3
S27 A/C compressor/boost cut-out microswitch Lower left side of engine 232-1
S27/1 A/C compressor out-out microswitch Lower left side of engine
S27/2 Deceleration shut-off microswitch Top left rear of engine, on bracket above intake manifold 232-1
S27/3 Microswitch (EGR) Top rear of engine, on throttle linkage bracket 248-6
S29/2 Throttle valve switch, full load/idle Left side of engine, lower left of airflow sensor housing 231-6
S29/3 Idle speed contact switch Top of accelerator pedal 251-4
S31/1 Refrigerant pressure switch, 2 function (off 2.0/30.0 bar, on 2.6/22.0 bar) Lower left front of engine compartment 230-6
S32 Refrigerant high pressure switch, auxiliary fan (off 15.0 bar/on 20.0 bar) (green) Lower left front of engine compartment 230-6
S32/1 Refrigerant high pressure switch, /-VC compressor (off 12.0 bar/on 16.0 bar) Lower left front of engine compartment
S40 Cruise control switch: V Decelerate/set; B Accelerate/set; SP Resume; A Off Left side of steering column
S40/1 Clutch pedal switch (cruise control) Top of clutch pedal bracket
S41 Coolant level switch Right side of engine compartment, lower front of coolant reservoir 229-5
S42 Washer fluid level switch Top of windshield washer fluid reservoir 229-5
S43 Oil level switch Left side of oil pan 238-2
S47 Left front door actuator In left front door 235-3
S48 Right front door actuator ln right front door
S49 Trunk lid lock actuator Center of rear trunk panel (sedan) 236-6
S49 Trunk lid lock actuator In tailgate (wagon) 241-5
S50 Outside mirror control switch Center console
S51/1 Left front seat heater switch Center console
S51/2 Right front seat heater switch Center console
S51/5 Driver seat contact switch, seat belt extender In left front seat
S52 Rear head restraint release switch Center console, above radio
S52/5 Rear head restraint release switch Under rear hatshelf
S59 Adjustable steering column switch Lower left side of steering column
S61 Automatic antenna switch Center console, above radio
S62 Hood switch (ATA) Left side ot component compartment 231-4
S62/1 Left front door switch (ATA) Left door jamb
S62/2 Right front door switch (ATA) Right door jamb
S62/3 Trunk lid switch (ATA) Tailgate latch (wagon)
S65 Transmission overload protection switch Left front of transmission 251-2
S66 Engine overload protection switch Top left side of engine
S68/1 Driver seat belt buckle switch (seat belt warning buzzer) Left front seat belt buckle (coupe)
S68/2 Front passenger seat belt buckle switch (seat belt extender) Right front seat belt buckle (coupe)
S68/3 Driver seat belt buckle switch (airbag/ETR) Left front seat belt buckle
S68/4 Front passenger seat belt buckle switch (airbag/ETR) Right front seat belt buckle
S76 Snow chain switch (ASR) with indicator Center console, above radio
S78/1 Rear window wiper switch: 1 Continuous wipe; 2 Intermittent wipe Center console, above radio (wagon)
S78/2 Rear window washer switch Center console, above radio (wagon)
S79 Rear window sun shade switch (center console) Center console, above radio
S88/2 Trunk lid lock switch (convenience) Part of trunk lock

SUPPLEMENT 14 - W124 COMPONENTS - continued

Component......Component Designation...Location...............Page - Figure

T1 Ignition coil Left side of engine compartment 231-1
T1/1 Ignition coil 1 (right cylinder bank) Left side of engine compartment, behind headlamp 250-3
T1/2 Ignition coil 2 (left cylinder bank) Left side of engine compartment, behind headlamp 250-3
V1 Convenience diode Rear of fuse box, location 1 233-5
V5 Disconnect diode Fuse/Relay box, position 1
W1 Main ground (behind instrument cluster) Behind left side of instrument cluster 235-5
W2 Ground, at right headlamp unit Lower right front of engine compartment 230-1
W3 Ground, left front wheelhousing (at ignition coil) Left side of engine compartment, on ignition coil bracket 234-5
W4 Ground, front dome lamp Center of windshield header, above front dome lamp 235-1
W5 Ground, engine Front of engine, on A/C compressor 230-4
W6 Ground, left rear wheelhousing in trunk Left side of trunk, below hinge (sedan) 232-5
W6 Ground, left rear wheelhousing in trunk Behind left rear quarter panel (wagon) 242-1
W7 Ground, right rear wheelhousing in trunk Right rear side of trunk (sedan) 235-6
W7 Ground, right rear wheelhousing in trunk Behind right rear quarter panel (wagon) 242-3
W8 Ground, tailgate (cable connector) Left corner of tailgate, behind panel 241-5
W9 Ground, at left headlamp unit Lower left front of engine compartment, near headlamp 230-5
W10 Ground, battery Right side of component compartment, rear of shock tower 229-1
W11 Ground, engine (connection point for ground wires) Left front of engine, on intake manifold 232-1
W12 Ground, center console Behind lower front of console 240-2
W13 Ground, heated rear window At right C-pillar, near edge of glass 237-1
W14 Ground, ABS hydraulic unit bracket Lower left front corner of engine compartment 231-2
W16 Ground, component compartment Right side of component compartment 250-1
W27 Ground, module box bracket Right side of component compartment 250-1
X1/4 Connector, automatic antenna Center of dashboard, rear of radio
X1/5 Connector, sound system feed (amplifier), terminal 30 Next to connector X30
X4 Terminal block, terminal 30, fuse and relay box (2-pole) Top of driver’s footwwell, forward of parking brake lever 234-4
X4/10 Terminal block, terminal 30/terminal 61 (battery) Right side of component compartment below W10 229-2
X4/10 Terminal block, terminal 30/terminal 61 (battery) Right side of component compartment below W10 249-6
X4/13 Terminal block, terminal 87 Right side of component compartment on rear firewall 229-4
X6 Terminal block, terminal 58d (2-pole) Center of dashboard, below radio 240-3
X6/1 Terminal block, terminal 68D (2-pole) Center of dashboard, left of ashtray 241-1
X6/2 Connector, terminal 58Fl (1-pole) Below rear of fuse box
X8 Terminal block, tailgate Top left rear of roof, above headllner 241-6
X8/2 Connector, backup lamp/rear window wiper (1-pole) Top of driver’s footwell
X8/3 Connector, combination switch/rear window wiper (1-pole) Top of driver’s footwell
X11 Diagnostic socket/terminal block (circuit TD) On left inner fender 234-5
X11/4 Test connection for diagnosis, (impulse readout, 16-pole) Right side of component compartment, left of battery (6 cylinder) 245-2
X11/4s1 Pushbutton switch with LED (California) part of X11/4 245-2
X11/4 Test connection for diagnosis, (impulse readout, 38-pole) Top of Module box (8 cylinder) 249-5
X11/11 Test connection, TD (EDS, 1-pole) Right side of component compartment, left of battery
X11/13 Test connection, SRS plug connection (1O~poIe) Beneath front passenger footrest 244-3
X11/18 Connector, ABS/ASR/electronic accelerator - chassis (6-pole) Forward of passenger side airbag, on firewall
X11/21 Diagnostic module test connection (3-pole) - California Right side of component compartment, in front of Module box 249-5
X11/21s1 Pushbutton (with LED) - California part of X11/21 249-5
X13 Connector, cigar lighter Behind center of dashboard, near ashtray
X18 Connector, interior/taillamp harness (8-pole) Lower part of fuse box 233-5
X20 Connector, stop lamp switch (2-pole) Driver’s footwell, on stop lamp switch 234-2
X20/1 Connector, center high-mounted stop lamp Lower part of fuse box 233-5
X21/2 Terminal block, stop lamp switch/electronic speedometer Behind instrument cluster
X22/1 Connector, transmission overload protection (2-pole) Left side of component compartment, beneath Fuse/Relay box (F1)
X22/6 Connector, transmission overload switch (starter lockout/kickdown harness) (3-pole) On transmission, near steering lock
X24 Connector, headlamp harness (6-pole) Lower part of fuse box 239-5
X25 Connector, preglow harness On left inner fender
X26 Connector, interior/engine (12-pole) Lower part of fuse box 239-5
X26/6 Connector, engine harness/Tempmatic (3-pole) Lower part of fuse box 245-3
X26/17 Engine plug connection Right side of component compartment, behind Module box
X26/18 Connector, interior/transmission (8-pole)
X27 Connector, starter harness Left side of component compartment, near brake booster 231-3
X28/1 Connector, ETR voltage supply (2-pole) Behind left side of dashboard, near steering column
X28/4 Connector, driver airbag squib Center of steering wheel, beneath slip ring
X28/5 Airbag squib slip ring (2-pole) Center of steering wheel, beneath air bag
X28/6 Connector, seat belt warning unit/seat belt warning unit relay Upper part of driver’s footwell
X28/7 Connector, airbag/test connection ln loom tie attached to harness, forward of passenger side airbag
X30 Connector, block for optional electrical equipment Behind driver’s left kickpanel 234-2
X30/1 Connector, multi-function block Behind driver’s left kickpanel
X32 Connector, trunk/reading lamp Pig-tail connection behind rear dome lamp
X33/4 Connector, cruise control (manual transmission) (2-pole) Upper part of driver’s footwell
X33/14 Connector, cruise control, cockpit/engine (10-pole) Forward of passenger side airbag, on firewall
X34 Connector, right front door contact switch In right front door jamb 246-2
X35/7 Plug connection, cockpit/module box (12-pole) Forward of passenger side airbag, on firewall
X35/8 Plug connection, cockpit/module box, electronic accelerator/cruise control/idle speed control (14-pole) Forward of passenger side airbag, on firewall
X36 Connector, fuel pump harness (1-pole) Behind passengers right kickpanel (On early vehicles: in right component compartment) 229-3
X36/3 Connector, fuel pump harness (2-pole) Beneath right side of rear seat 248-4
X39/16 Connector, telephone voltage supply (1-pole) Behind driver’s left kickpanel

SUPPLEMENT 14 - W124 COMPONENTS - continued

Component......Component Designation...Location...............Page - Figure

X42 Connector, anti-theft alarm, frontfrear Beneath passengers footrest 244-3
X42/2 Connector, right rear door contact switch/dome lamp(ATA) (1-pole) In right B-pillar
X42/9 Connector, left front door ATA harness In driver’s left kickpanel, near floor
X42/10 Connector, right front door ATA harness In passengers right kickpanel, near floor 240-1
X42/11 Connector, tailgate ATA harness (3-pole) Top right rear of roof, above headliner 243-6
X42/13 Connector, ATA/radio (1-pole) Rear of radio 244-6
X42/14 Connector, ATA/trunk lamp ln left front corner of trunk
X42/15 Connector, ATA/switched ground Left component compartment 239-5
X43 Connector, central locking system (ATA) Beneath right side of rear seat 233-3
X44 Connector, central locking system (supply pump) Beneath right side of rear seat
X46 Connector, ABS warning lamp (1-pole) Behind dashboard, forward of parking brake lever 234-4
X47 Connector, rear speed sensor harness (2-pole) Beneath right side of rear seat 233-3
X47/2
X48F Right rear door sill area
X48G Behind radio
X48H Behind radio
X48I Rear of center console
X48K Sensors ground, CIS-E
X48L EZL reference resistor
X48M Ground, start valve/fuel pump relay
X49/1 Connector, backup lamp switch Top of driver’s footwell, right of steering column
X49/2 Connector, backup lamp/starter lock-out switch Top of driver’s footwell, right of steering column 234-2
X53/1 Connector, Hall-effect sensor/automatic climate control Connected to X53/5
X53/2 Connector, Hall-effect sensor/Tempomat (cruise control) Connected to X53/5
X53/5 Multipoint connector, Hall-effect sensor Behind right side of instrument cluster 240-4
X53/6 Connector, Hall-effect sensor/CIS-E (1pole) Connected to X53/5
X55 Connection board, left front power seat Beneath left front seat 245-1
X55/1 Connection board, right front power seat Beneath right front seat 236-5
X56 Connector, throttle valve switch On intake manifold, near airflow sensor 234-6
X62/3 Connector, rear axle speed sensor, ASR (6-pole) Behind front passengers right kickpanel 252-2
X62/6 Connector, right front wheel speed sensor (component compartment) Right side of component compartment 250-1
X52/7 Connector, left front wheel speed sensor (component compartment) Component compartment
X62/8 Connector, rear axle multiple circuit junction Underside of car, forward of fuel pump package 252-6
X62/11 Terminal block, rear axle speed sensor (ABS) (2-pole) Behind passengers right kickpanel
X63 Connector, serial data feed CIS-E/EZL (1-pole) Top of driver’s footwell, next to steering column 234-2
X63/1 Connector, CAN databus, EZl_/LH (3-pole) Right front footwell
X64 Connector, blower speed control/interior harness Above and rearward of brake booster
X81/1 Connector, engine harness/cruise control (1-pole) Near connector X30
X83/2 Connector, ABS/ASD/ASR warning lamp, right footwell (3-pole) Top of driver’s footwell, forward of parking brake release lever
X83/3 Connector, instrument cluster/4MATIC warning lamp (3-pole) Top of driver’s footwell, forward of parking brake release lever
X83/5 Connector, instrument cluster/ABS/ASR warning lamp (3-pole) Top of driver’s footwell, forward of parking brake release lever
X86 Connector, central locking system rear (3 pin) Right side of tailgate header, above headliner 243-6
X88/3 Connector, windshield washer fluid level control (2-pole) Near coolant level switch, coolant reservoir
X88/5 Connector, left front brake pad wear sensor Below right side of fuse box, on left inner fender 237-2
X89/1 Connector, electronic accelerator control unit/ASR (2-pole) Right side of component compartment, behind battery 253-3
X89/2 Connector, electronic accelerator control unit/engine harness (2-pole) Right side of component compartment, behind battery 253-3
X95 Connector, CHECK ENGINE On right inner firewall, near battery
X132 Connector, right front brake pad sensor (2 pin) On right inner firewall, forward of battery 229-1
Y1 Electrohydraulic actuator (EHA) Top of engine, rear of fuel distributor 234-6
Y3 Kickdown valve (automatic transmission) Right rear corner of transmission 237-4
Y3/2 Upshift delay solenoid valve On left side of transmission 251-2
Y3/3 Upshift delay switchover valve Left side of component compartment 249-4
Y6 Idle speed air valve Top left front of engine, left of engine oil dipstick 231-6
Y7 Switchover valve unit (7 connections) Above passenger footwell area
Y8 Start valve Top center of engine, rear of fuel distributor 231-6
Y19 Mono valve (ACC) Right side of component compartment, next to battery 229-1
Y22 Electromagnetic actuator, electronic idle speed control (ELR) Lower left side of engine
Y24/2 Head restraint release valve with shut-off delay Below left side of rear seat 233-2
Y24/3 Seat backrest locking valve Below left side of rear seat
Y27 EGR switchover valve Right front fender, behind air filter housing 248-1
Y27/4 Boost pressure control switchover valve Right front engine compartment, next to fan shroud 248-5
Y27/5 Pressure control flap switchover valve Right front fender, forward of air filter housing 248-5
Y29 Vacuum amplifier switchover valve (automatic transmission) Left side of engine compartment, on inner fender
Y30 Engine overload protection switchover valve Left side of engine compartment, on component compartment wall
Y31 Air recirculation valve vacuum transducer Right side of engine compartment, rearof right headlamp
Y31/1 EGR valve vacuum transducer Right front fender, behind airfilter housing 247-4
Y31/2 Pressure control flap vacuum transducer Right side of engine compartment, rear of right headlamp 247-4
Y31/4 Boost pressure control vacuum transducer Right side of engine compartment, rear of right headlamp 247-4
Y32 Air injection pump switchover valve Right front lender, behind headlamp 248-1
Y33 Electromagnetic air injection pump clutch Front of air injection pump, above alternator 250-2
Y38 ASD valve Rear underside of car, next to fuel pump package 252-3
Y49 Solenoid, adjustable camshaft timing Attached to intake camshaft front cover 250-6
Y49/1 Solenoid, left adjustable camshaft timing Attached to left intake camshaft cover 249-2
Y49/2 Solenoid, right adjustable camshaft timing Attached to left intake camshaft cover 249-2
Y58 Tank breather valve
Y58/1 Purge switchover valve On right side of component compartment wall, above N1/2, N1/3 253-2
Y62 Fuel injection valves (LH) Top of engine 249-2
Z Connector sleeve (solder joint in harness)
Z6 Connector sleeve, ground (solder joint in harness)
Z6/8 Connector sleeve, sensor ground (solder joint in harness) Inside N39 plug
Z6/9 Connector sleeve, ground W10 (solder joint in harness) ATA/comfort system, right rear door sill area
Z7 Connector sleeve, terminal 30 (solder joint in harness) Cable tray above intake manifold, area of rear most bolt hole
Z7/1 Connector sleeve, terminal 30, central locking system (solder joint in harness) 80 mm from Z6
Z7/4 Connector sleeve, terminal 87, engine (LH)
Z7/5 Connector sleeve, terminal 87, engine (LH)
Z7/6 Connector sleeve, terminal 87, chassis (LH) 240 mm from Z6
Z7/15 Connector sleeve, terminal 87 (LH) 160 mm from Z6
Z13 Connector sleeve 5 (solder joint in harness) Ground, throttle switch/CIS-E (30cm towardsd N3 from end of cable tray)
Z22 Cable protectively tied back to harness
Z24/1 Connector sleeve, ATA arm
Z24/2 Connector sleeve, ATA disarm
Z82 Connector sleeve, ATA/central locking system, trunk On floor, near right “B" pillar
Z82/1 Connector sleeve, ATA/central locking system, left front door On floor, near right “B” pillar
Z82/2 Connector sleeve, ATA/central locking system, right front door On floor, near right “B” pillar
Z82/6 Connector sleeve, warning buzzer contact/illumination Central locking, right rear door sill area
Z94 Connector sleeve, brake lamp switch closer
Z95 Connector sleeve, brake lamp switch opener

Wiring Diagram Files - 1st 10 - Index and 9 more (there are 209 of them)

SUPPLEMENT 10 - W124 AUTOMATIC CLIMATE CONTROL

INDEX................................301

ACC Grounds Distribution.....312 313
ACC Power Distribution.........312 313
Air Delivery..........................303 304
Blower Control......................302 311
Component Location Table.....401
Compressor Clutch Control.....305 306 307 308 309 310
Pushbutton Control Assembly..301





Wiring Diagram Files - 10 through 19