1998 MITSUBISHI MONTERO sensor

pressure regulator diaphragm opens relief valve, allowing pressure to
bleed off through fuel return line, reducing fuel pressure.
As engine manifold vacuum decreases (open throttle), fuel
pressure regulator diaphragm closes valve, preventing pressure from
bleeding off through fuel return line, increasing fuel pressure.
FUEL CONTROL
Fuel Injectors
Fuel is supplied to engine through electronically pulsed
(timed) injector valves located on fuel rail(s). PCM controls amount\
of fuel metered through injectors based on information received from
sensors.
IDLE SPEED
Air Conditioning (A/C) Relay
When A/C is turned on with engine at idle, PCM signals IAC
motor to increase idle speed. To prevent A/C compressor from switching
on before idle speed has increased, PCM momentarily opens A/C relay
circuit.
Idle Air Control (IAC) Motor
Motor controls pintle-type air valve to regulate volume of
intake air at idle.
During start mode, PCM controls idle intake air volume
according to Engine Coolant Temperature (ECT) sensor input. After
starting, with idle position switch activated (throttle closed), fast
idle speed is controlled by IAC motor and fast idle air control valve
(if equipped).
When idle switch is deactivated (throttle open), IAC motor
moves to a preset position in accordance with ECT sensor input.
PCM signals IAC motor to increase engine RPM in the following
situations: A/T (if applicable) is shifted from Neutral to Drive, A/C
is turned on, or power steering pressure reaches a preset value.
IGNITION SYSTEMS
DIRECT IGNITION SYSTEM (DIS)
Depending on number of cylinders, ignition system is a 2 or
3-coil, distributorless ignition system. On Eclipse (Turbo) and DOHC
V6 engines, Camshaft Position (CMP) sensor is located beside camshaft,\
in front of engine. On all other engines equipped with DIS, CMP sensor
is a separate unit mounted in place of distributor. On DOHC 4-
cylinder, DOHC V6 and 1.8L 4-cylinder engines with California
emissions, Crankshaft Position (CKP) sensor is located beside
crankshaft, in front of engine. PCM determines TDC based on pulse
signals received from sensors and then controls MFI and ignition
timing.
Power Transistors & Ignition Coils
Based on crankshaft position and CMP sensor inputs, PCM
controls timing and directly activates each power transistor to fire
coils. On 4-cylinder engines, power transistor "A" controls primary
current of ignition coil "A" to fire spark plugs on cylinders No. 1
and No. 4 at the same time. Power transistor "B" controls primary
current of ignition coil "B" to fire spark plugs on cylinders No. 2
and No. 3 at the same time. On V6 engines, companion cylinders No. 1
and 4, 2 and 5, and 3 and 6 are fired together.
On all models, although each coil fires 2 plugs at the same
time, ignition takes place in only one cylinder, since the other

cylinder is on its exhaust stroke when plug fires.
HALL EFFECT IGNITION SYSTEM
This system is equipped with a Hall Effect distributor.
Shutter(s) attached to distributor shaft rotate through distributor
Hall Effect switch, also referred to as a Camshaft Position (CMP)
sensor, which contains a distributor pick-up (a Hall Effect device and
magnet). As shutter blade(s) pass through pick-up, magnetic field is
interrupted and voltage is toggled between high and low. PCM uses this
data along with Crankshaft Position (CKP) sensor data to control
ignition timing and injector pulse width to maintain optimum
driveability.
Power Transistor & Ignition Coil
Power transistor is mounted inside distributor with disc and
optical sensing unit. When ignition is on, ignition coil primary
circuit is energized. As distributor shaft rotates, disc rotates,
triggering optical sensing unit. PCM receives signals from optical
sensing unit. Signals are converted and sent to power transistor,
interrupting primary current flow and inducing secondary voltage.
IGNITION TIMING CONTROL SYSTEM
Ignition timing is controlled by PCM. PCM adjusts timing
based on various conditions such as engine temperature, altitude and
detonation.
EMISSION SYSTEMS
EXHAUST GAS RECIRCULATION (EGR) CONTROL
Federal Emissions (Non-Turbo)
To lower oxides of nitrogen (NOx) exhaust emissions, a non-
computer controlled exhaust gas recirculation system is used. EGR
operation is controlled by throttle body ported vacuum. Vacuum is
routed through vacuum control valve to prevent EGR operation at low
engine temperatures.
Spring pressure holds EGR valve closed during low vacuum
conditions (engine idling or wide open throttle). When vacuum pressure\
increases and overcomes EGR spring pressure, EGR valve is lifted to
allow exhaust gases to flow into intake manifold for combustion.
California Emissions & Turbo
PCM controls EGR operation by activating EGR control solenoid
valve according to engine load. When engine is cold, PCM signals EGR
control solenoid valve to deactivate EGR.
EGR Control Solenoid Valve
Valve denies or allows vacuum supply to EGR valve based on
PCM commands.
EVAPORATIVE CONTROL
Fuel evaporation system prevents fuel vapor from entering
atmosphere. System consists of special fuel tank with vapor separator
tanks (if equipped), vacuum relief filler cap, overfill limiter (2-wa\
y
valve), fuel check valve, thermovalve (if equipped), charcoal
canister, purge control valve, purge control solenoid valve, and
connecting lines and hoses.
Purge Control Solenoid Valve

Door Lock Control Unit Behind left side of dash.
ELC 4-Speed Automatic Transmission
Control Module Behind left side of dash.
Engine Control Module (ECM) Behind right kick panel.
Keyless Entry Control Unit Behind right side quarter
panel.
Rear Differential Lock Control Unit Mounted on top of left rear
wheelwell.
SRS Air Bag Control Unit Behind center of dash.
Sun Roof Control Unit On center of roof, behind
sun roof.
Variable Shock Absorber Control Unit Behind left rear wheelwell,
behind quarter panel.
4WD Indicator Control Unit Behind center of dash.









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MOTORS









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Component Component Location








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Blower Motor Behind right side of dash.
Condenser Fan Motor On left front of engine
compartment.
Fuel Pump In fuel tank.
Headlight Washer Motor Right side of engine
compartment, in washer fluid
reservoir.
Idle Air Control Motor On throttle body.
Motor Antenna Rear of right front wheelwell.
Rear Differential Lock Air Pump On left rear of vehicle.
Rear Washer Motor In rear of cargo area.
Rear Wiper Motor On center of tailgate.
Sun Roof Motor On center of roof, behind
sun roof.
Windshield Washer Motor Bottom of windshield washer
reservoir.
Windshield Wiper Motor On left side of firewall.









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SENDING UNITS & SENSORS

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ABS Speed Sensors (4) On bracket, on each wheel hub.\
Air Inlet Sensor In evaporator air duct.
Camshaft Position Sensor At bottom of left camshaft
gear.
Crankshaft Position Sensor Above crankshaft gear.
Engine Coolant Temperature Gauge Unit On thermostat housing.
Engine Coolant Temperature Sensor On thermostat housing.
Front Impact Sensor (Left) (SRS) On left front of engine
compartment.
Front Impact Sensor (Right) (SRS) On right front of engine
compartment.
Fuel Gauge Unit In fuel tank.
Fuel Tank Differential Pressure Sensor
(Calif.) Top of fuel tank.
G-Sensor (ABS) In center console, rear of
parking brake lever.
Geomagnetic Sensor (Compass) On top center of dash.

Heated Oxygen Sensor (Front)
(Federal) Underside of vehicle, forward
of catalytic converter.
Heated Oxygen Sensor (Front)
(Left Bank) (Calif.) In left exhaust manifold.
Heated Oxygen Sensor (Front)
(Right Bank) (Calif.) In right exhaust manifold.
Heated Oxygen Sensor (Rear)
(Federal) Underside of vehicle, behind
catalytic converter.
Heated Oxygen Sensor (Rear) (Left Bank)
(Calif.) In left exhaust pipe, below
engine.
Heated Oxygen Sensor (Rear) (Right Bank)
(Calif.) In right exhaust pipe, below
engine.
Input Shaft Speed Sensor On side of transmission.
Intake Air Temperature Sensor Mounted on outside of
evaporator case.
Manifold Differential Pressure Sensor On top left rear of engine.
Output Shaft Speed Sensor On rear of transmission.

Outside Air Temperature Sensor Below left headlamp.
Park/Neutral Position Sensor On left side of transmission.
Throttle Position Sensor On throttle body.
Vehicle Speed Sensor (VSS) On transmission tailshaft.
Volume Airflow Sensor In air cleaner duct (includes
intake air temperature sensor
& barometric pressure sensor).









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SOLENOIDS & SOLENOID VALVES









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Component Component Location








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ABS Hydraulic Unit (w/Built-In
Solenoid Valve) In right rear corner of engine
compartment.
Cruise Control Actuator (w/Built-In
Control Valve & Release Valve)
(Calif.) In right rear of engine
compartment.
Cruise Control Actuator (w/Built-In
Control Valve & Release Valve)
(Federal) In left rear of engine
compartment.
EGR Solenoid In right rear of engine
compartment.
ELC 4-Speed Automatic Transmission
Control Solenoid Inside transmission.
Evaporative Emission Purge Solenoid On front of engine.
Evaporative Emission Ventilation
Solenoid In left rear of engine
compartment.
Solenoid Valves "A" & "B" In right side of engine
compartment.









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SWITCHES









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Component Component Location








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A/T Fluid Temperature Switch On left side of transmission.
Brake Fluid Level Switch In brake master cylinder
reservoir.
Center Differential Lock Detection
Switch On transfer case.

* ELECTRICAL SYSTEM UNIFORM INSPECTION GUIDELINES *
1998 Mitsubishi Montero
GENERAL INFORMATION
Electrical System Motorist Assurance Program
Standards For Automotive Repair
All Makes and Models
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
CONTENTS
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
OVERVIEW OF SERVICE REQUIREMENTS & SUGGESTIONS
ACTUATOR MOTORS (SOLENOIDS) (ELECTRIC)
ACTUATOR MOTORS (VACUUM)
AIR BAGS
ALTERNATORS AND GENERATORS
AMPLIFIERS
ANTENNAS
BATTERIES
BATTERY CABLES
BATTERY CABLES
BATTERY HOLD DOWN HARDWARE
BATTERY TRAYS AND HOLD DOWN HARDWARE
BATTERY WIRES
BELTS
BULB SOCKETS
BULBS, SEALED BEAMS AND LEDS
CD PLAYERS
CIGARETTE LIGHTER ASSEMBLIES
CIRCUIT BREAKERS
CLUTCH SWITCHES
CONNECTORS
CONTROL MODULES
CRUISE CONTROL BRAKE SWITCHES
CRUISE CONTROL CABLES
CRUISE CONTROL CLUTCH SWITCHES
CRUISE CONTROL LINKAGES AND CABLES
CRUISE CONTROL RESERVOIRS
CRUISE CONTROL TUBES
CRUISE CONTROL VACUUM DUMP RELEASE VALVES
CRUISE CONTROL VACUUM HOSES, TUBES AND RESERVOIRS
CRUISE CONTROL VEHICLE SPEED SENSORS
DEFOGGERS
DEFROSTERS
DELAYS
DIMMERS
ELECTRIC HEATERS
EQUALIZERS
FUSE BLOCKS
FUSE BOXES AND BLOCKS
FUSES, FUSIBLE LINKS AND CIRCUIT BREAKERS
FUSIBLE LINKS
GAUGES
GENERATORS
GROUND CABLES AND STRAPS
GROUND STRAPS
HEADLIGHT ADJUSTERS
HEATING ELEMENTS (DEFROSTERS, DEFOGGERS, ELECTRIC HEATERS AND SEATS)
HORNS AND SIRENS

IGNITION SWITCHES
INDICATOR LIGHTS
KEYLESS ENTRY KEYPADS AND TRANSMITTERS
KEYLESS ENTRY TRANSMITTERS
LEDS
LENSES
MICROPHONES
MIRRORS (ELECTROCHROMATIC AND HEATED)
MOTORS
NEUTRAL SAFETY SWITCHES
ODOMETERS
ODOMETERS, SPEEDOMETERS AND TACHOMETERS (CABLE-DRIVEN)
PULLEYS
RECEIVERS, AMPLIFIERS, EQUALIZERS AND SUB-WOOFER VOLUME CONTROLS
RELAY BOXES
RELAYS
SEALED BEAMS
SEAT HEATERS
SECURITY ALARM SENSORS
SIRENS
SOLENOIDS
SPEAKERS AND MICROPHONES
SPEEDOMETER AND TACHOMETER LINKAGES AND CABLES
SPEEDOMETER CABLES
SPEEDOMETERS
STARTERS
SUB-WOOFER VOLUME CONTROLS
SWITCHES
TACHOMETER CABLES
TACHOMETERS
TAPE PLAYERS AND CD PLAYERS
TENSIONERS
TIMERS
TIRE PRESSURE SENSORS
TRANSCEIVERS
TRANSDUCERS
VACUUM ACCUMULATORS (RESERVOIRS)
VACUUM RESERVOIRS
VOLTAGE REGULATORS
WASHER FLUID LEVEL SENDERS
WASHER PUMPS
WIPER ARMS AND BLADES
WIPER BLADES
WIPER HOSES AND NOZZLES
WIPER LINKAGES
WIPER NOZZLES
WIPER PUMP RESERVOIRS
WIRING HARNESSES AND CONNECTORS
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
OVERVIEW OF MOTORIST ASSURANCE PROGRAM
The Motorist Assurance Program is the consumer outreach
effort of the Automotive Maintenance and Repair Association, Inc.
(AMRA). Participation in the Motorist Assurance Program is drawn from
retailers, suppliers, independent repair facilities, vehicle
manufacturers and industry associations.
Our organization's mission is to strengthen the relationship
between the consumer and the auto repair industry. We produce
materials that give motorists the information and encouragement to
take greater responsibility for their vehicles-through proper,