check engine MITSUBISHI MONTERO 1998 Service Manual
[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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H - TESTS W/O CODES
1998 Mitsubishi Montero
1998 ENGINE PERFORMANCE
Mitsubishi - Trouble Shooting - No Codes
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport,
3000GT
INTRODUCTION
Before using this article to diagnose symptoms or
intermittent faults, perform testing in F - BASIC TESTING article and
G - TESTS W/CODES article. Use this article to diagnose driveability
problems existing when a hard Diagnostic Trouble Code (DTC) is not
present.
NOTE: Some driveability problems may have been corrected by
manufacturer with a revised Powertrain Control Module (PCM).
Check with manufacturer for latest PCM.
Symptom checks can direct technician to malfunctioning
component(s) for further diagnosis. A symptom should lead to a
specific component, system test or adjustment.
Use intermittent test procedures to locate driveability
problems that DO NOT occur when vehicle is being tested. These test
procedures should also be used if an intermittent DTC was present, but
no problem was found during self-diagnostic testing.
NOTE: For specific testing procedures, see G - TESTS W/CODES
article. For specifications, see D - ADJUSTMENTS or
C - SPECIFICATIONS article.
SYMPTOMS
SYMPTOM DIAGNOSIS
Symptom checks cannot be used unless problem occurs while
vehicle is being tested. Before using this article to diagnose any
symptom, perform basic diagnostic procedures in F - BASIC TESTING
article and self-diagnostics in G - TESTS W/CODES article in order to
reduce diagnostic time. The following symptoms are available for
diagnosis:
* Difficult To Start/No Start (Cranks Okay)
* Rough Or Unstable Idle
* Engine Hesitates Or Poor Acceleration
* Engine Surges
* Detonation Or Knocking
* Poor Fuel Mileage
DIFFICULT TO START/NO START (CRANKS OKAY)
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check ignition switch.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check park/neutral position switch (A/T).
* Check volume airflow sensor.
* Check engine coolant temperature sensor.
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* Check power supply to PCM.
* Check fuel pressure.
* Check ignition timing.
* Check for disconnected or damaged vacuum hoses.
* Check for control relay malfunction.
* Check for SFI system malfunction.
* Check for fuel pump drive control system malfunction.
* Check for ignition coil malfunction.
* Check for power transistor malfunction (if applicable).
* Check for fuel injector malfunction.
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ROUGH OR UNSTABLE IDLE
* Check intake air temperature sensor.
* Check EVAP purge control solenoid valve (if applicable).
* Check vehicle speed sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for disconnected or damaged vacuum hoses.
* Check for SFI system malfunction.
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
* Check for vehicle speed sensor malfunction.
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ENGINE HESITATES OR POOR ACCELERATION
* Check intake air temperature sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check ignition coil.
* Check EGR control solenoid valve (if applicable).
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for disconnected or damaged vacuum hoses.
* Check for SFI system malfunction.
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* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
* Check A/C switch and power relay (if applicable).
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ENGINE SURGES
* Check engine coolant temperature sensor.
* Check EGR control solenoid valve (if applicable).
* Check fuel pressure.
* Check for fuel injector malfunction.
DETONATION OR KNOCKING
* Check for knock sensor malfunction (if applicable).
* Check volume airflow sensor.
* Check for engine cooling system problems.
* Check fuel quality.
* Check intake air temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition coil.
* Check power transistor (if applicable).
* Check for EGR system malfunction.
POOR FUEL MILEAGE
* Check intake air temperature sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for SFI system malfunction.
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
INTERMITTENTS
INTERMITTENT PROBLEM DIAGNOSIS
Intermittent fault testing requires duplicating circuit or
component failure to identify problem. These procedures may lead to
computer setting a Diagnostic Trouble Code (DTC) which may help in
diagnosis.
If problem vehicle does not produce DTCs, monitor voltage or
resistance values using a DVOM while attempting to reproduce
conditions causing intermittent fault. A status change on DVOM
Page 817 of 1501
I - SYSTEM/COMPONENT TESTS
1998 Mitsubishi Montero
1998 ENGINE PERFORMANCE
Mitsubishi - System & Component Testing
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport,
3000GT
INTRODUCTION
NOTE: Testing individual components does not isolate shorts or
opens. Perform all voltage tests using a Digital
Volt-Ohmmeter (DVOM) with minimum 10-megohm input impedance,
unless stated otherwise in test procedure. Use ohmmeter to
isolate wiring harness shorts or opens. Testing procedures
not covered in this article require a scan tool. See
G - TESTS W/CODES article.
Before testing separate components or systems, perform basic
diagnostic procedures in F - BASIC TESTING article. Since many
computer-controlled and monitored components set a diagnostic trouble
code if they malfunction, also perform self-diagnostics in G - TESTS
W/CODES article.
AIR INDUCTION SYSTEMS
TURBOCHARGER
Turbocharger Pressure Check
1) Disconnect Black turbocharger pressure control hose at
wastegate solenoid valve, and plug valve nipple. Attach pressure gauge
to hose. Drive vehicle and accelerate engine, in 2nd gear, to 3500 RPM
or more. Check turbocharger pressure when pressure gauge stabilizes.
See TURBOCHARGER PRESSURE SPECIFICATIONS table.
2) If pressure gauge reading is more than specified, check
wastegate actuator. See DTCs P1103 and P1104 in G - TESTS W/CODES
article. Replace wastegate actuator as required. If pressure gauge
reading is less than specified, check for malfunctioning wastegate
valve, turbocharger pressure leaks and faulty turbocharger.
TURBOCHARGER PRESSURE SPECIFICATIONS TABLE
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Application Pressure psi (kg/cm)
Eclipse ................................ 6.4-14.7 (.4-1.0)
3000GT ................................... 2.9-8.7 (.2-.6)
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Air By-Pass Valve
Remove air by-pass valve. Valve is mounted to intake air duct
between air-to-air intercooler and intake plenum. Apply vacuum to
diaphragm of vacuum valve. Valve should begin opening at approximately
16 in. Hg. Observe operation of valve through by-pass opening.
Wastegate Actuator Test
Actuator is mounted on turbocharger. For testing procedures,
see DTCs P1103 and P1104 in G - TESTS W/CODES article.
Wastegate Control Solenoid Valve Test
On Eclipse, valve is mounted to top back section of air
cleaner. On 3000GT, valve is mounted to firewall, beside EGR solenoid.
Page 818 of 1501
For testing procedures, see DTCs P1103 and P1104 in G - TESTS W/CODES
article.
COMPUTERIZED ENGINE CONTROLS
CONTROL UNIT
NOTE: For Powertrain Control Module (PCM) location, see
POWERTRAIN CONTROL MODULE (PCM) LOCATION table. To identify
PCM power and ground terminals, see appropriate pin voltage
chart in J - PIN VOLTAGE CHARTS article. To identify PCM
power and ground circuits, see appropriate wiring diagram in
L - WIRING DIAGRAMS article.
Ground Circuits
1) Turn ignition off. Using an ohmmeter, check continuity
between chassis ground and PCM ground terminal(s). See Figs. 1-5.
Ohmmeter should indicate zero ohms. If reading is not as specified,
check and repair open circuit between PCM connector and chassis
ground. If reading is as specified, go to next step.
2) Connect voltmeter negative lead to chassis ground. Connect
positive lead to PCM ground terminal(s). With engine running,
voltmeter should indicate less than one volt. If reading is more than
one volt, check for open, corrosion or loose connection in ground
circuit.
Power Circuits
Turn ignition on. Check for battery voltage on both PCM power
terminals. See Figs. 1-5. If battery voltage is not present, check
operation of MFI relay. See RELAYS under MOTORS, RELAYS & SOLENOIDS.
POWERTRAIN CONTROL MODULE (PCM) LOCATION TABLE
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Application Location
Eclipse 2.0L Non-Turbo .................. In Front Of Left
Front Strut Tower
Mirage & Montero Sport .............. Behind Right Side Of
Instrument Panel (Glove Box)
Montero ........................... Right Front Kick Panel
All Other Models ................... Behind Center Console
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Fig. 1: Identifying PCM Terminals (Diamante)
Courtesy of Mitsubishi Motor Sales of America
Fig. 2: Identifying PCM Terminals (Eclipse 2.0L Non-Turbo)
Courtesy of Mitsubishi Motor Sales of America
Page 821 of 1501
See TURBOCHARGER under AIR INDUCTION SYSTEMS.
FUEL SYSTEM
FUEL DELIVERY
NOTE: For fuel system pressure testing, see
F - BASIC TESTING article.
Fuel Pressure Regulator Control Solenoid Valve (Turbo Models)
See G - TESTS W/CODES article.
FUEL CONTROL
Fuel Injectors
See G - TESTS W/CODES article.
IDLE CONTROL SYSTEM
ELECTRICAL LOAD SWITCH
3000GT (DOHC)
1) Turn ignition off. Disconnect PCM connector. See
POWERTRAIN CONTROL MODULE (PCM) LOCATION table under COMPUTERIZED
ENGINE CONTROLS. Go to next step.
2) Turn headlights on. Using DVOM, check voltage between PCM
connector terminal No. 58 and chassis ground. If battery voltage is
present, turn headlights off and go to next step. If battery voltage
is not present, check and repair circuit between headlight relay
connector and PCM connector.
3) Turn defogger switch on. Using DVOM, check voltage between
PCM connector terminal No. 58 and chassis ground. If battery voltage
is present, turn defogger switch off and go to next step. If battery
voltage is not present, check and repair circuit between defogger
relay connector and PCM connector.
4) Turn blower switch on. Using DVOM, check voltage between
PCM connector terminal No. 58 and chassis ground. If battery voltage
is present, turn blower switch off and go to next step. If battery
voltage is not present, check and repair circuit between blower switch
connector and PCM connector.
5) If battery voltage is present and preceding tests do not
show any system or component malfunction and PCM is suspected,
substitute PCM with known-good unit and retest system.
IDLE AIR CONTROL (IAC) MOTOR
For testing procedures, see G - TESTS W/CODES article.
IGNITION SYSTEM
NOTE: For basic ignition checks, see F - BASIC TESTING article.
TIMING CONTROL SYSTEMS
Camshaft Position Sensor
See G - TESTS W/CODES article.
Crankshaft Position Sensor
See G - TESTS W/CODES article.
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Knock Sensor
See G - TESTS W/CODES article.
EMISSION SYSTEMS & SUB-SYSTEMS
EXHAUST GAS RECIRCULATION (EGR)
EGR Control Solenoid Valve
See G - TESTS W/CODES article.
FUEL EVAPORATION
EVAP Purge Control Valve
See G - TESTS W/CODES article.
EVAP Purge Control Solenoid Valve
See G - TESTS W/CODES article.
POSITIVE CRANKCASE VENTILATION (PCV)
PCV Valve
Remove PCV valve. Shake valve. Valve should rattle if moving
freely. Apply air pressure to valve. Air should flow freely in one
direction only. Connect PCV valve to vacuum hose and start engine.
Ensure vacuum is flowing through valve.
MISCELLANEOUS CONTROLS
NOTE: Although the controlled devices listed here are not
technically engine performance components, they can affect
driveability if they malfunction.
NOTE: To identify PCM A/C power supply voltage terminals, see
appropriate pin voltage chart in J - PIN VOLTAGE CHARTS
article. To identify PCM A/C power supply circuit, see
appropriate wiring diagram in L - WIRING DIAGRAMS article.
A/C Switch & Compressor Clutch Relay
Using DVOM, check A/C power supply voltage from PCM. Turn
ignition switch to OFF position. Disconnect PCM connector. Turn A/C
switch and ignition switch to ON position. Check voltage between PCM
A/C power supply terminal and chassis ground. If battery voltage is
not as present, check and repair circuit(s).
Page 823 of 1501
INSTRUMENT PANEL
1998 Mitsubishi Montero
1998 ACCESSORIES & EQUIPMENT
Mitsubishi - Instrument Panels
Eclipse, Galant, Mirage, Montero, Montero Sport, 3000GT
DESCRIPTION & OPERATION
WARNING: Deactivate air bag system before performing any service
operation. See AIR BAG RESTRAINT SYSTEMS article. Do not
apply electrical power to any component on steering column
without first deactivating air bag system. Air bag may
deploy.
Instrument cluster includes speedometer, fuel gauge and
temperature gauge. Fuel gauge has a built-in voltage limiter to keep
voltage supply to gauges at 7 volts. Some models may also have an
ammeter, oil pressure gauge, tachometer, voltmeter and/or turbo boost
pressure gauge. Oil pressure gauge uses full battery voltage.
Tachometer operates by pulse feed.
COMPONENT LOCATIONS
COMPONENT LOCATIONS TABLE \
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Component Location
Engine Coolant Temperature (ECT) Sensor
Eclipse, Galant, Montero
& Montero Sport ................. On Thermostat Housing
Mirage ........................ On Rear Of Cylinder Head
3000GT ........... On Cylinder Head, Below Ignition Coil
Input Speed Sensor
Eclipse ........................... On Side Of Transaxle
Output Speed Sensor
Eclipse ........................... On Side Of Transaxle
Vehicle Speed Sensor
Eclipse, Galant,
Mirage & 3000GT ................... On Top Of Transaxle
Montero & Montero Sport ...... On Transmission Tailshaft
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TROUBLE SHOOTING
FUEL/TEMPERATURE GAUGE NOT WORKING
Check for blown fuse, faulty voltage limiter and faulty
relay. Ensure sending unit connections are clean and tight. Test
sending unit for correct operation. Tighten connections in instrument
cluster.
SPEEDOMETER NOT WORKING
On mechanical-type speedometers, ensure speedometer cable is
properly connected and correctly routed. If speedometer pointer and/or
odometer still do not work, replace speedometer cable or speedometer
assembly.
On electric-type speedometers, check for faulty vehicle speed
sensor, input/output sensors or faulty circuit. For testing, see
Page 834 of 1501
Eclipse 2.0L Non-Turbo With A/T
Disconnect sensor harness connector. Check resistance between
sensor terminals. Resistance should be 300-1200 ohms. Replace sensor
as necessary.
OIL PRESSURE GAUGE
Circuit Test (Eclipse, Montero & 3000GT)
1) Disconnect oil pressure gauge wiring connector from
sending unit inside engine compartment. Connect a 12-volt test light
between harness connector terminal and ground. Turn ignition on, but
DO NOT start engine.
2) If test light comes on and gauge needle moves, go to GAUGE
RESISTANCE TEST. If test light does not come on and gauge needle does
not move, repair wiring to sending unit.
Gauge Resistance Test (Eclipse, Montero & 3000GT)
1) Remove instrument cluster from instrument panel. See
INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. On 3000GT, remove air
distribution duct and combination gauges.
2) On all models, check continuity between oil pressure gauge
terminals. See Fig. 17, 18 or 19. See
OIL PRESSURE GAUGE RESISTANCE SPECIFICATIONS table. If resistance is
not within specification, replace oil pressure gauge.
OIL PRESSURE GAUGE RESISTANCE SPECIFICATIONS TABLE
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Application Ohms
Eclipse & 3000GT ................................... 40-44
Montero ............................................... 50
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Fig. 17: Oil Pressure Gauge Resistance Test Terminals (Eclipse)
Courtesy of Mitsubishi Motor Sales of America
Page 836 of 1501
unit. Turn ignition on. Check voltage between ground and sending unit
harness-side connector. If battery voltage is present, problem is
intermittent. If battery voltage is not present, go to next step.
2) Check sending unit harness connector. Repair as necessary.
If connector is okay, check circuit (Yellow wire) between oil pressure\
gauge and oil pressure sending unit. See WIRING DIAGRAMS. Repair as
necessary. If circuit is okay, go to next step.
3) Remove multi-meter assembly. Check voltage between ground
and harness-side connector terminal No. 10 (Red/Black wire). See
WIRING DIAGRAMS . If battery voltage is present, problem is
intermittent. If battery voltage is not present, go to next step.
4) Check harness connector to multi-meter assembly. Repair as
necessary. If connector is okay, check circuit between multi-meter
harness connector and fusible link No. 6. See WIRING DIAGRAMS. Repair
as necessary. If circuit is okay, go to next step.
5) Turn ignition on. Check voltage between ground and multi-
meter harness-side connector terminal No. 11 (Black/White wire). See
WIRING DIAGRAMS . If battery voltage is present, problem is
intermittent. If battery voltage is not present, go to next step.
6) Check harness connector to multi-meter assembly. Repair as
necessary. If connector is okay, check circuit between multi-meter
assembly harness connector and ignition switch. See WIRING DIAGRAMS.
Repair as necessary. If circuit is okay, go to next step.
7) Turn ignition off. Check continuity between ground and
multi-meter assembly harness-side connector terminal No. 3 (Black
wire). If continuity is present, problem is intermittent. If
continuity is not present, go to next step.
8) Check harness connector to multi-meter assembly. Repair as
necessary. If connector is okay, check circuit (Black wire) between
multi-meter assembly harness connector and ground. See WIRING DIAGRAMS
. Repair as necessary. If circuit is okay, problem is intermittent.
Gauge Sending Unit Resistance Test (Montero Sport)
Disconnect harness connector to oil pressure sending unit.
Start and idle engine. Check resistance between oil pressure gauge
sending unit terminal and engine block. Resistance should be about 2
ohms. Replace sending unit if resistance is not as specified.
REED SWITCH
Continuity Check (Montero)
1) Remove instrument cluster. See INSTRUMENT CLUSTER under
REMOVAL & INSTALLATION. Check continuity between reed switch terminals
No. 1 and 2. See Fig. 20.
2) Ensure continuity pulses on and off 4 times per revolution
of speedometer shaft connection. If continuity is not as specified,
replace reed switch.
Fig. 20: Identifying Reed Switch Test Terminals (Montero)
Courtesy of Mitsubishi Motor Sales of America
SPEEDOMETER TEST