oil temperature MITSUBISHI MONTERO 1998 User Guide
[x] Cancel search | Manufacturer: MITSUBISHI, Model Year: 1998, Model line: MONTERO, Model: MITSUBISHI MONTERO 1998Pages: 1501, PDF Size: 25.81 MB
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If DTC 51 is set also, go to DTC 51: 1ST GEAR RATIO SIGNAL
INCORRECT test. If DTC 51 is not set, check overdrive brake for a
mechanical failure. See OVERDRIVE BRAKE in MITSUBISHI R4AW3 & V4AW3
OVERHAUL article.
SYMPTOM TROUBLE SHOOTING
NOTE: Check system using appropriate scan tool. See WIRING DIAGRAMS
for electrical schematics and COMPONENT TESTING.
COMMUNICATION WITH SCAN TOOL NOT POSSIBLE
If scan tool cannot communicate with TCM, check proper
connection with DLC. Check TCM power circuits, TCM ground circuits and
malfunctioning TCM.
SHIFT POINTS INCORRECT
If shift points are incorrect, check for DTCs. If no DTC is
present, check oil temperature sensor, pattern select switch, 4WD low
range detection switch and TCM for proper operation.
UPSHIFTS OCCUR SPONTANEOUSLY
If upshifting occurs spontaneously, check park/neutral
position switch, overdrive switch and TCM for proper operation.
TCC LOCK-UP MALFUNCTIONING
If TCC lock-up system is not operating properly, check torque
converter, valve body, lock-up switch and oil temperature switch.
COMPONENT TESTING
A/T FLUID TEMPERATURE SWITCH
1) Remove fluid temperature switch, located to rear of
neutral safety switch. Immerse switch in container of ATF up to top
threaded portion of switch. Using a DVOM, check continuity between
switch terminals. Continuity should not exist when fluid temperature
is 257
F (125C) or less.
2) When fluid is heated to 289-304F (143-151C), continuity
should exist. Replace switch if necessary. Apply thread sealant to
fluid temperature switch threads and install in transmission.
BRAKELIGHT SWITCH
1) Disconnect electrical connector from brakelight switch,
located near brake pedal. Using ohmmeter, ensure continuity exists
between terminal No. 2 (White/Red wire) and terminal No. 3 (Green
wire) with brake pedal released. Replace brakelight switch if
continuity does not exist. Continuity should not exist between
terminals No. 2 and No. 3 with brake pedal depressed.
2) If continuity does not exist, ensure brake pedal is
properly adjusted so brakelight switch has proper travel for switch
operation. If proper brakelight switch travel exists, replace
brakelight switch.
ENGINE COOLANT TEMPERATURE (ECT) SENSOR
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Disconnect electrical connector from coolant temperature
sensor. Using ohmmeter, check resistance between terminals of coolant
temperature sensor. Resistance should be as specified in accordance
with the TEMPERATURE-TO-RESISTANCE VALUES table. Replace coolant
temperature if resistance is not within specification.
TEMPERATURE-TO-RESISTANCE VALUES
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Temperature F (C) Ohms
32 (0) ......................................................... 5.8\
68 (20) ........................................................ 2.4\
104 (40) ....................................................... 1.1\
176 (80) ....................................................... 0.3\
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INPUT SPEED SENSOR
Disconnect solenoid and sensor connector. Using ohmmeter,
measure resistance between terminals No. 9 and No. 10. See Fig. 9.
Resistance should be 560-680 ohms at 68
F (20C). If resistance is not
as specified, replace No. 2 speed sensor.
OIL TEMPERATURE SENSOR
Disconnect solenoid and sensor connector. Using ohmmeter,
check resistance between sensor connector terminals No. 1 and No. 2.
See Fig. 9 . Resistance should be 10 k/ohms when oil temperature is
77
F (25C). With oil temperature at 248F (120C), resistance should
be 615 ohms. If resistance is not as specified, replace oil
temperature sensor.
OUTPUT SPEED SENSOR
Disconnect solenoid and sensor connector. Using ohmmeter,
measure resistance between terminals No. 3 and No. 4. See Fig. 9.
Resistance should be 560-680 ohms at 68
F (20C). If resistance is not
as specified, replace output speed sensor.
OVERDRIVE SWITCH
Using a screwdriver, remove overdrive switch from selector
lever, located below selector lever button. Using a DVOM, check
continuity between overdrive switch terminals No. 3 and 5 with switch
in ON position. Continuity should exist. With switch in OFF position,
check continuity between terminals No. 3 and 4. Continuity should
exist. If continuity is not as specified, replace switch. See Fig. 10.
Fig. 10: Identifying Overdrive Switch Terminals
Courtesy of Mitsubishi Motor Sales of America.
PARK/NEUTRAL POSITION (PNP) SWITCH
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until brakelight plunger contacts brake pedal.
2) Loosen brakelight switch 1/2 to one turn. Install and
tighten lock nut on brakelight switch. Install electrical connector.
Ensure brakelights and cruise control operate properly.
INPUT SPEED SENSOR
Removal & Installation
Disconnect electrical connector. Remove bolt securing sensor
to transmission. Remove input speed sensor from transmission. See
Fig. 14 . To install, reverse removal procedure.
Fig. 14: Locating Input Speed Sensor
Courtesy of Mitsubishi Motor Sales of America.
OIL TEMPERATURE SENSOR
Removal & Installation
Sensor is located on transmission connected to cooler line,
near PNP switch. Disconnect electrical connector. Remove oil
temperature sensor from transmission. To install, reverse removal
procedure using NEW gasket.
OUTPUT SPEED SENSOR
Removal & Installation
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D - ADJUSTMENTS
1998 Mitsubishi Montero
1998 ENGINE PERFORMANCE
Mitsubishi - On-Vehicle Adjustments
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport,
3000GT
ENGINE MECHANICAL
Before performing any on-vehicle adjustments to fuel or
ignition system, ensure engine mechanical condition is okay (i.e.,
engine compression).
VALVE CLEARANCE
VALVE ADJUSTMENT
NOTE: All models use hydraulic valve lifters. Adjustment is not
required.
CHECKING HYDRAULIC VALVE LIFTERS
1) Warm engine to normal operating temperature. Remove valve
cover. Position cylinder No. 1 at TDC on compression stroke. On 4-
cylinder engines, check intake rockers on cylinders No. 1 and 2. Check
exhaust rockers on cylinders No. 1 and 3. On V6 engines, check intake
rockers on cylinders No. 1, 5 and 6. Check exhaust rockers on
cylinders No. 1, 2 and 3.
2) Push downward on end of rocker arm, above lash adjuster.
Rotate crankshaft 360 degrees. On 4-cylinder engines, check intake
rockers on cylinders No. 3 and 4. Check exhaust rockers on cylinders
No. 2 and 4. On V6 engines, check intake rockers on cylinders No. 2, 3
and 4. Check exhaust rockers on cylinders No. 4, 5 and 6. If lash
adjuster is normal, it will feel solid.
3) If lash adjuster moves downward easily when pushed,
replace adjuster. If lash adjuster feels soft or spongy, air has
probably entered lash adjuster. If this occurs, check engine oil
level. If engine oil level is okay, check oil screen and oil screen
gasket for damage.
4) After repairing cause of air ingestion, warm engine to
operating temperature. Drive vehicle at low speed for approximately 5
minutes. Turn engine off for a few minutes.
5) Restart engine and drive at low speed for approximately 5
minutes. Repeat this step several times for about one hour. This helps
remove air from engine oil.
IGNITION TIMING
NOTE: Perform all checks with engine at normal operating
temperature, cooling fan and accessories off, transmission
in Park or Neutral, and front wheels in straight-ahead
position. Ignition timing check procedure for Eclipse 2.0L
non-turbo not available from manufacturer at time of
publication.
Diamante
1) Ignition timing is controlled by Powertrain Control Module
(PCM) and is not adjustable. Manufacturer provides procedure for
checking timing. DO NOT attempt to adjust ignition timing by rotating
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HO2S detects oxygen content in exhaust gas and sends this
information to PCM. PCM uses input signals from HO2S to vary duration
of fuel injection. HO2S heater stabilizes sensor temperature
regardless of exhaust gas temperature to allow for more accurate
exhaust oxygen content readings.
Idle Air Control (IAC) Valve Position Sensor
Sensor is incorporated in IAC motor. Sensor senses IAC motor
plunger position and sends electrical signal to PCM.
Ignition Timing Adjustment Terminal
Used for adjusting base ignition timing. When terminal is
grounded, PCM timing control function is by-passed, allowing base
timing to be adjusted.
Intake Air Temperature (IAT) Sensor
IAT sensor is incorporated into airflow sensor assembly. This
resistor-based sensor measures temperature of incoming air and
supplies air density information to PCM.
Knock Sensor (KS)
KS is located in cylinder block and senses engine vibration
during detonation (knock). KS converts vibration into electrical
signal. PCM retards ignition timing based on this signal.
Manifold Differential Pressure (MDP) Sensor
MDP sensor converts negative air pressure in intake manifold
plenum into voltage signals sent to PCM. PCM monitors Exhaust Gas
Recirculation (EGR) system using these signals.
Park/Neutral Position (PNP) Switch (Automatic Transmission)
PNP switch senses position of transmission select lever,
indicating engine load due to automatic transmission engagement. Based
on this signal, PCM commands IAC motor to increase throttle angle,
maintaining optimum idle speed.
Power Steering Oil Pressure Switch
Switch detects increase in power steering oil pressure. When
power steering oil pressure increases, switch contacts close,
signaling PCM. PCM commands IAC motor, raising idle speed to
compensate for drop in engine RPM due to power steering load.
Throttle Position (TP) Sensor
TP sensor is a variable resistor mounted on throttle body.
PCM uses voltage signal from TP sensor to determine throttle plate
angle.
Vehicle Speed Sensor (VSS)
Mounted on transaxle/transmission, VSS sends a pulsing signal
to PCM for vehicle speed calculation. PCM uses this calculation for
cruise control and fuel cut-off.
Volume Airflow (VAF) Sensor
Incorporated into airflow sensor assembly, VAF sensor
measures intake airflow rate. Intake air flows through tunnel in
airflow sensor assembly. VAF sensor sends frequency signal to PCM. PCM
uses signal to adjust fuel injection rate.
OUTPUT SIGNALS
NOTE: Vehicles are equipped with various combinations of
computer-controlled components. Not all components listed
below are used on every vehicle. To determine component
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usage on specific models, see appropriate wiring diagram in
L - WIRING DIAGRAMS article. For theory and operation on each
output component, refer to system indicated after component.
Data Link Connector (DLC)
See SELF-DIAGNOSTIC SYSTEM .
EGR Control Solenoid Valve
See EXHAUST GAS RECIRCULATION (EGR) CONTROL under EMISSION
SYSTEMS.
Fuel Injectors
See FUEL CONTROL under FUEL SYSTEM.
Fuel Pressure Control Solenoid Valve (Turbo)
See FUEL DELIVERY under FUEL SYSTEM.
Fuel Pressure Regulator
See FUEL DELIVERY under FUEL SYSTEM.
Idle Air Control (IAC) Motor
See IDLE SPEED under FUEL SYSTEM.
Malfunction Indicator Light
See SELF-DIAGNOSTIC SYSTEM .
Power Transistor(s) & Ignition Coils
See IGNITION SYSTEMS .
Purge Control Solenoid Valve
See EVAPORATIVE CONTROL under EMISSION SYSTEMS.
Wastegate Control Solenoid Valve
See TURBOCHARGED ENGINES under AIR INDUCTION SYSTEM.
FUEL SYSTEM
FUEL DELIVERY
Electric fuel pump, located in gas tank, feeds fuel through
in-tank fuel filter, external fuel filter (located in engine
compartment) and fuel injector rail.
Fuel Pump
Fuel pump consists of a motor-driven impeller. Pump has an
internal check valve to maintain system pressure, and a relief valve
to protect fuel pressure circuit. Pump receives voltage supply from
MFI control relay.
Fuel Pressure Control Solenoid Valve (Turbo)
Valve prevents rough idle due to fuel percolation. On engine
restart, if engine coolant or intake air temperature reaches a preset
value, PCM applies voltage to fuel pressure control solenoid valve for
2 minutes after enginerestart. Valve will open, allowing atmospheric
pressure to be applied to fuel pressure regulator diaphragm. This
allows maximum available fuel pressure at injectors, enriching fuel
mixture and maintaining stable idle at high engine temperatures.
Fuel Pressure Regulator
Located on fuel injector rail, this diaphragm-operated relief
valve adjusts fuel pressure according to engine manifold vacuum.
As engine manifold vacuum increases (closed throttle), fuel
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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
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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
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When engine is off, fuel vapors are vented into charcoal
canister. When engine is warmed to normal operating temperature and
running at speeds greater than idle, PCM energizes purge control
solenoid valve, allowing vacuum to purge valve.
Canister vapors are then drawn through solenoid valve into
intake manifold for burning. Purge control solenoid valve remains
closed during idle and engine warm-up to reduce HC (hydrocarbons) and
CO (carbon monoxide) emissions.
POSITIVE CRANKCASE VENTILATION (PCV) VALVE
PCV valve operates in closed crankcase ventilation system.
Closed crankcase ventilation system consists of PCV valve, oil
separator, breather and ventilation hoses.
PCV valve is a one-way check valve located in valve cover.
When engine is running, manifold vacuum pulls PCV valve open, allowing
crankcase fumes to enter intake manifold. If engine backfires through
intake manifold, PCV valve closes to prevent crankcase combustion.
SELF-DIAGNOSTIC SYSTEM
NOTE: PCM diagnostic memory is retained by direct power supply
from battery. Memory is not erased by turning off ignition,
but it will be erased if battery or PCM is disconnected.
Self-diagnostic system monitors input and output signals
through the Data Link Connector (DLC). Diagnostic Trouble Codes (DTCs\
)
can only be read using a scan tester. For additional information, see
G - TESTS W/CODES article.
Malfunction Indicator Light (MIL)
MIL (CHECK ENGINE light) comes on when ignition is turned on.\
MIL remains on for several seconds after engine has started. If an
abnormal input signal occurs, MIL comes on and code is stored in
memory. If an abnormal input signal returns to normal, PCM turns MIL
off, but code remains stored in memory until it is cleared. If
ignition is turned on again, MIL will not come on until PCM detects
malfunction during system operation.
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Center Differential Lock Operation
Detection Switch On transfer case.
Dual Pressure Switch On high pressure line, on
receiver-drier.
Engine Coolant Temperature Switch Top right front of engine.
Free Wheel Engage Switch Right side of engine
compartment.
High Range/Low Range Detection Switch On transfer case.
Low Range Operation Detection Switch On transfer case.
Oil Pressure Switch Lower left front of engine.
Parking Brake Switch At base of parking brake
lever.
Power Steering Pressure Switch On power steering pump.
Rear Differential Lock Detection
Switch Under rear of vehicle, on
differential.
Reed Switch Integral with speedometer.
Seat Belt Switch On driver-side seat belt
buckle.
Stoplight Switch On bracket, above brake pedal.
2WD/4WD Detection Switch On transfer case.
4WD Operation Detection Switch On transfer case.
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MISCELLANEOUS
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Component Component Location \
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Amplifier Under center console, below
floor.
Data Link Connector (DLC) Behind left side of dash,
near relay box.