Mercedes-Benz 300TE 4Matic 1990 - ELECTRICAL COMPONENT LOCATOR 1990-91 MERCEDES-BENZ ELECTRIC COMPONENT LOCATOR

Mercedes-Benz 300TE 4Matic 1990 - BUZZERS, RELAYS & TIMERS

Mercedes-Benz 300TE 4Matic 1990 BUZZERS, RELAYS & TIMERS LOCATION

Component	Location
A/C Auxiliary Fan Relays (See View "C")	In fuse/relay block. See Fig. 1 .
A/C Auxiliary Fan Pre-Resistor Relay (See View "B")	In fuse/relay block. See Fig. 1 .
Anti-Theft Alarm Relay (See View "E")	In fuse/relay block. See Fig. 1 .
CIS-E Fuel Injection Overvoltage Protection Relay (See View "D")	Behind battery, left of CIS-E control unit. See Fig. 2 .
CIS-E Fuel Injection Overvoltage Protection Relay	Behind battery, left of CIS-E control unit. See Fig. 3 .
Combination Relay (Turn Signal, Rear Defogger, Windshield Wiper) (See View "H")	In fuse/relay block. See Fig. 1 .
Convenience Relay (See View "F")	In fuse/relay block. See Fig. 1 .
Cruise Control/Engine Overload Protection Relay	Behind battery, left of CIS-E overvoltage protection relay.
Dome Light Delay Relay	In front dome light assembly.
Fuel Pump Relay (See View "C")	Behind battery on left end of CIS-E control unit. See Fig. 2 .
Fuel Pump Relay	Behind battery on left end of CIS-E control unit. See Fig. 3 .
Head Restraint Adjustment Relay	Underneath applicable seat.
Headlight Washer Relay (See View "D")	In fuse/relay block. See Fig. 1 .
Heated Seat Relays	Under carpet in front of both front seats.
Power Seat Relay (See View "A")	In fuse/relay block. See Fig. 1 .
Rear Window Intermittent Wiper Timer (Wagon)	Inside left rear corner of tailgate.
Restart Delay Relay
300E, 300CE, 300TE	In fuse/relay box.
300SEL	At right front of brake booster.
Seat Belt Warning Relay
Coupe (See View "G")	In fuse/relay block. See Fig. 1 .
Sedan	In driver's side kick panel.
Transmission Upshift Delay Relay	Behind battery, left of CIS-E overvoltage protection relay.

Mercedes-Benz 300TE 4Matic 1990 - CIRCUIT PROTECTION DEVICES

Mercedes-Benz 300TE 4Matic 1990 CIRCUIT PROTECTION DEVICES LOCATION

Component	Location
Automatic Climate Control (ACC) Blower Motor Fuse	Mounted on top of left strut tower. See Fig. 4 .
Fuse/Relay Box	At left rear corner of engine compartment. See Fig. 4 .

Mercedes-Benz 300TE 4Matic 1990 - CONTROL UNITS

Mercedes-Benz 300TE 4Matic 1990 CONTROL UNITS LOCATION

Component	Location
ABS Control Unit	Behind battery and behind CIS-E control unit. See Fig. 3 .
A/C Compressor Control Unit	Behind battery, and behind fuel pump relay. See Fig. 3 .
A/C Temperature Control Unit	Under right side of dash, behind glove box.
Anti-Theft Alarm Control Unit	Behind right side of passenger foot rest, near kick panel.
Catalytic Converter Warning Control Unit	Under left dash, left of brake pedal.
CIS-E Fuel Injection Control Unit
300 E, CE, TE (See View "A")	Near right side of firewall, directly behind battery. See Fig. 2 .
300 E, CE, TE	Near right side of firewall, directly behind battery. See Fig. 5 .
300 SE, SEL, SL	Behind right kick panel.
300 SL	Under right front of dash.
Convenience Control Unit	Under left side of rear seat.
Daytime Running Light (DRL) Control Unit	Centered, behind right side foot rest.
Electronic Blower Regulator Control Unit	In center of cowl, next to heater core.
Electronic Ignition Control Unit (EZL)	On left front inner fender panel, next to diagnostic connector. See Fig. 4 & Fig. 6 .
Exterior Light Failure Monitoring Unit (See View "K")	In fuse/relay box. See Fig. 1 .
Engine Systems Control Unit (MAS)	Behind battery, right of ABS control unit.
Heated Seat Control Unit	Under left side of rear seat.
Illumination Control Unit	On steering column, behind instrument column.
Left Front Power Seat & Steering Column Adjustment Control Unit	Under left front seat.
Radio Amplifier Control Unit	In right front corner of trunk.
SRS Control Unit	On top of transmission tunnel, behind front console.
Warning Module	Behind instrument cluster, on steering column.

Mercedes-Benz 300TE 4Matic 1990 - SENDING UNITS & SENSORS

Mercedes-Benz 300TE 4Matic 1990 SENDING UNITS & SENSORS LOCATION

Component	Location
ABS Wheel Speed Sensors
Front	At steering knuckle.
Rear	On right front of rear differential.
A/C Compressor RPM Sensor	On back of A/C compressor.
A/C In-Car Temperature Sensor	In dome light assembly and within aspirator blower.
Ambient Temperature Sensor 1	On blower motor housing, left of wiper motor.
Ambient Temperature Sensor 2	On left front corner of of front bumper.
Brake Wear Sensors	In front brake pads.
Camshaft Position Sensor	On left side of camshaft front cover. See Fig. 4 .
Catalytic Converter Temperature Sensors	In exhaust manifold downpipes, after pre-catalytic converters.
Coolant Temperature Sending Unit (EZL)	On left side of cylinder head, near rear of head. See Fig. 4 .
Coolant Temperature Sensors (CTS)
Auto. Climate Control (ACC)	Near center of left side of cylinder head, forward of sending unit. See Fig. 4 .
Electronic Ignition System (EZL)	At left rear corner of cylinder head. See Fig. 4 & Fig. 6 .
Electronic Ignition System (EZL) (See View "F")	At left rear corner of cylinder head. See Fig. 2 .
Crankshaft Position Sensor	At top of bellhousing, behind oil filter.
Evaporator Temperature Sensor	On left side of evaporator housing, above accelerator pedal.
Fuel Level Sensor	On top of fuel tank.
Heater Core Temperature Sensor	Behind center of dashboard, below radio.
Intake Air Temperature Sensor	On air filter housing inlet duct.
Knock Sensors	On intake manifold, near cylinders No. 2 & 5.
Oil Pressure Sensor	At bottom, rear of oil filter housing. Above starter bolts.
Oxygen Sensor (Heated)	In exhaust pipe, before catalytic converter.
Starter Ring Gear Sensor	Lower left side of bellhousing.
TDC Sensor	On front of engine, above vibration damper.
Vehicle Speed Sensor (Hall Effect)	On back of speedometer.

Mercedes-Benz 300TE 4Matic 1990 - MOTORS

Mercedes-Benz 300TE 4Matic 1990 MOTORS LOCATION

Component	Location
A/C Heater Blower Motor	Center front of cowl, behind panel. Near wiper motor.
Adjustable Steering Column Motor	Left side of column, under lower dash panel.
Auxiliary Coolant Pump (Heater)	At left rear of engine, near steering box unit.
Auxiliary Fan(s)	Front of radiator.
Fuel Pump(s)
300 E, CE, TE	In front of right rear axle shaft.
300 SE, SEL, SL	Above rear axle housing.
Headlight Washer Pump	In base of windshield washer reservoir. See Fig. 4 .
Headlight Wiper Motors	Underneath and rear of each headlight assembly.
Rear Window Sun Shade Motor	In trunk, underneath rear shelf.
Rear Window Washer Motor	At right rear corner of trunk, behind fuel tank filler tube.
Sliding/Pop-Up Sun Roof Motor
Sedan	On top of left rear wheelwell.
Wagon	Inside left rear quarter panel.
Supply Vacuum Pump Motor (Central Lock System)	Inside box, below right rear seat.
Vacuum Pump Motor	Below right side of rear seat.
Windshield Washer Pump	At right front of engine compartment, in reservoir. See Fig. 4 .
Windshield Wiper Motor
Front	Center front of cowl, behind panel. Left of battery. See Fig. 4 .
Rear (Wagon)	Inside center of tailgate.

Mercedes-Benz 300TE 4Matic 1990 - SOLENOIDS & SOLENOID VALVES

Mercedes-Benz 300TE 4Matic 1990 SOLENOIDS & SOLENOID VALVES LOCATION

Component	Location
Adjustable Camshaft Timing Solenoids	Mounted to front of camshaft front cover.
Idle Speed Air Valve	On top of intake manifold, in front of fuel distributor. See Fig. 6 .
Idle Speed Air Valve (See View "I")	On top of intake manifold, in front of fuel distributor. See Fig. 2 .
Kickdown Solenoid (A/T)	At bottom, right rear of transmission.
Upshift Delay Solenoid Valve	On left side of transmission.

Mercedes-Benz 300TE 4Matic 1990 - SWITCHES

Mercedes-Benz 300TE 4Matic 1990 SWITCHES LOCATION

Component	Location
A/C High Pressure Switch	On receiver-drier, behind left headlights.
A/C Receiver-Drier Pressure Switches	On receiver-drier, behind left headlights. See Fig. 4 .
A/T Overload Protection Switch	At left front of transmission.
Back-Up Light Switch	On left side of transmission.
Brake Fluid Level Switch	In top of brake fluid reservoir.
Brake/Stoplight Switch	On top of brake pedal bracket.
Clutch Pedal Switch (Cruise Control)	On top of pedals bracket.
Coolant Level Switch	In lower front of coolant reservoir, at right front fender panel.
Cruise Control Warning Switch	In engine compartment, next to fuse/relay block.
Deceleration Shut-Off Microswitch	At top, rear of intake manifold, on throttle body linkage bracket. See Fig. 6 .
Deceleration Shut-Off Microswitch (See View "J")	At top, rear of intake manifold, on throttle body linkage bracket. See Fig. 2 .
Evaporator Temperature Regulator Switch	In evaporator housing, above passenger's footwell.
Intake Manifold Pressure Switch	On top of intake manifold.
Kickdown Switch (A/T)	Under accelerator pedal.
Oil Level Switch	In left side of oil pan.
Parking Brake Switch	On parking brake support at left kick panel.
Power Seat Relay Switch(es)	In front door jambs, below door light switches.
Rear Head Restraint Control Switch	Under rear shelf, in luggage compartment.
Starter Lock-Out/Back-Up Light Switch	On left side of transmission.
Switching Valve	On underside of thermostat housing.
Throttle Valve Switch	On intake manifold, at base of throttle body. See Fig. 6 .
Throttle Valve Switch (See View "K")	On intake manifold, at base of throttle body. See Fig. 2 .
Windshield Washer System Heater Thermoswitch	Underside, left rear corner of engine hood.

Mercedes-Benz 300TE 4Matic 1990 - MISCELLANEOUS

Mercedes-Benz 300TE 4Matic 1990 MISCELLANEOUS LOCATION

Component	Location
A/C Voltage Regulator	Inside blower housing.
Airflow Sensor Position Indicator	In front side of fuel distributor. See Fig. 2 & Fig. 6 .
Auxiliary Fan Pre-Resistor	Behind left headlights, at lower front of inner fender panel. See Fig. 4 .
Cruise Control Actuator	Under left dash, to right of parking brake support.
Diagnostic Connectors (All Models)	On lower left front fender panel, forward of strut tower. See Fig. 4 & Fig. 6 .
Diagnostic Connectors (All Models) (See View "L")	On lower left front fender panel, forward of strut tower. See Fig. 2 .
California On-Board Diagnostics (16-Pole w/ LED)	On right side inner component wall, left of battery. See Fig. 4 .
California On-Board Diagnostics (16-Pole w/ LED) (See View "E")	On right side inner component wall, left of battery. See Fig. 2 .
California On-Board Diagnostics (SRS - 10-Pole)	Below passenger foot rest, right of anti-theft alarm control unit.
Power Seat Diode (See View "I")	In fuse/relay block. See Fig. 1 .
Reference Resistors
CIS-E Fuel Injection	Behind battery and behind CIS-E control unit. See Fig. 5 .
Cruise Control Amplifier	On bottom of cruise control amplifier.
EGR	Behind battery.
EZL	Near right rear of fuse/relay box, near brake booster. See Fig. 4 .
Elec. Idle Speed Control (ELR) Resistance Trimming Plug	At left of inner component wall, in front of brake booster.
SRS Engery Accumulator	Behind right kick panel, below SRS voltage converter.
SRS Voltage Converter	Behind right kick panel, above SRS energy accumulator.
Speedometer Transmitter	On left rear side of transmission.