F - BASIC TESTING
1998 Mitsubishi Montero
1998 ENGINE PERFORMANCE
Mitsubishi - Basic Diagnostic Procedures
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport,
3000GT
INTRODUCTION
The following diagnostic steps will help prevent overlooking
a simple problem. This is also where to begin diagnosis for a no-start
condition. The first step in diagnosing any driveability problem is
verifying the customer's complaint with a test drive under the
conditions the problem reportedly occurred.
Before entering self-diagnostics, perform a careful and
complete visual inspection. Most engine control problems result from
mechanical breakdowns, poor electrical connections or
damaged/misrouted vacuum hoses. Before condemning the computerized
system, perform each test listed in this article.
NOTE: Perform all voltage tests with a Digital Volt-Ohmmeter
(DVOM) with a minimum 10-megohm input impedance, unless
stated otherwise in test procedure.
PRELIMINARY INSPECTION & ADJUSTMENTS
VISUAL INSPECTION
Visually inspect all electrical wiring, looking for chafed,
stretched, cut or pinched wiring. Ensure electrical connectors fit
tightly and are not corroded. Ensure vacuum hoses are properly routed
and are not pinched or cut. See M - VACUUM DIAGRAMS article to verify
routing and connections (if necessary). Inspect air induction system
for possible vacuum leaks.
MECHANICAL INSPECTION
Compression
Check engine mechanical condition with a compression gauge,
vacuum gauge, or an engine analyzer. See engine analyzer manual for
specific instructions.
WARNING: DO NOT use ignition switch during compression tests on fuel
injected vehicles. Use a remote starter to crank engine.
Fuel injectors on many models are triggered by ignition
switch during cranking mode, which can create a fire hazard
or contaminate the engine's oiling system.
Check engine compression with engine at normal operating
temperature, all spark plugs removed and throttle wide open. See
COMPRESSION SPECIFICATIONS table.
COMPRESSION SPECIFICATIONS TABLE
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Application (1) Specification
Compression Ratio
1.5L (VIN A) ..................................... 9.0:1
1.8L (VIN C) ..................................... 9.5:1
2.0L
(VIN F) ........................................ 8.5:1
(VIN Y) ........................................ 9.6:1
2.4L (VIN G) ..................................... 9.5:1
3.0L
(VIN H) ........................................ 8.9:1
(VIN J) ....................................... 10.0:1
(VIN K) ........................................ 8.0:1
(VIN P) ........................................ 9.0:1
3.5L (VIN M & P) ................................. 9.0:1
Compression Pressure
1.5L (VIN A) ..................... 192 psi (13.4 kg/cm
)
1.8L (VIN C) ..................... 199 psi (13.9 kg/cm)
2.0L (VIN F) ..................... 178 psi (12.5 kg/cm)
2.0L (VIN Y) ............ 170-225 psi (11.7-15.5 kg/cm)
2.4L (VIN G) ..................... 192 psi (13.4 kg/cm)
3.0L
(VIN H & P) .................... 171 psi (12.0 kg/cm
)
(VIN J) ........................ 185 psi (13.0 kg/cm)
(VIN K) ........................ 156 psi (10.9 kg/cm)
3.5L (VIN M & P) ................. 171 psi (12.0 kg/cm)
Maximum Variation
Between Cylinders ( 2) ............... 14 psi (1.0 kg/cm
)
( 1) - See A - ENGINE/VIN ID article for VIN information.
( 2) - On Eclipse 2.0L non-turbo engine, maximum variation
between cylinders is 25%.
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Exhaust System Backpressure
The exhaust system can be tested with a vacuum or pressure
gauge. If using a pressure gauge, remove HO2S or air injection check
valve (if equipped). Connect a 0-5 psi pressure gauge and run engine
at 2500 RPM. If exhaust system backpressure is greater than 2 psi,
exhaust system or catalytic converter is plugged.
If using a vacuum gauge, connect vacuum gauge hose to intake
manifold vacuum port. Start engine. Observe vacuum gauge. Open
throttle part way and hold steady. If vacuum gauge indication slowly
drops after stabilizing, inspect exhaust system for restriction.
FUEL SYSTEM
* PLEASE READ THIS FIRST *
WARNING: ALWAYS relieve fuel pressure before disconnecting any fuel
injection-related component. DO NOT allow fuel to contact
engine or electrical components.
RELIEVING FUEL PRESSURE
1) On Diamante, disconnect fuel pump harness connector at
fuel tank from underneath vehicle. On Montero and Montero Sport,
remove cargo compartment carpet, remove access plate and disconnect
fuel pump harness connector. On all other models, remove rear seat
cushion, remove access plate (if required) and disconnect fuel pump
harness connector.
2) On all models, start engine. Let engine run until it
stops. Turn ignition off. Disconnect negative battery cable. Connect
fuel pump harness connector. Install rear seat and/or carpet as
necessary.
WARNING: Before disconnecting high pressure fuel hose at fuel
Application Wire Color Location
Diamante .................. Black/Blue ............ (1)
Eclipse (Turbo & 2.4L) .... Black/Blue ............. ( 2)
Galant .................... Black/Blue ............ ( 3)
Mirage .................... Black/Blue ............ ( 1)
Montero ...................... White .............. ( 4)
3000GT .................... Black/Blue ............ ( 6)
( 1) - On firewall, above brake master cylinder.
( 2) - On firewall behind battery.
( 3) - On main wiring harness, near center of firewall.
( 4) - On main wiring harness, near right center of firewall.
( 5) - Near left rear corner of engine compartment, below
cruise control actuator (if equipped).
( 6) - On main wiring harness, near wiper motor on firewall,
behind battery.
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3) Start engine and allow it to idle. Measure fuel pressure
with vacuum hose connected to fuel pressure regulator. Record fuel
pressure reading. See FUEL PUMP PERFORMANCE table. Disconnect and plug
vacuum hose from fuel pressure regulator. Record fuel pressure
reading.
4) Check for fuel pressure in fuel return hose by gently
pinching hose while increasing engine speed. If fuel volume is low,
fuel pressure in return hose will not be felt. Increase engine speed
to 2500-3000 RPM, 2-3 times. Return engine to idle. Fuel pressure
should not drop when engine is returned to idle.
5) Turn ignition off. Ensure fuel pressure reading does not
decrease within 2 minutes. If a decrease is noted, monitor speed of
decrease.
6) If fuel pressure is lower than specification, fuel
pressure drops at idle after increasing engine speed to 2500-3000 RPM,
or no fuel pressure in fuel return hose can be felt, check for clogged
fuel filter, or faulty fuel pressure regulator or fuel pump.
7) If fuel pressure is greater than specification, check for
a faulty fuel pressure regulator or plugged fuel return line. If fuel
pressure does not change when vacuum hose to regulator is connected or
disconnected, check for a leaking or clogged vacuum hose to fuel
pressure regulator or faulty fuel pressure regulator.
8) If fuel pressure decreases suddenly after engine is
stopped, check valve in fuel pump is not seated. Replace fuel pump. If
fuel pressure drops slowly, fuel injector is leaking or fuel pressure
regulator valve seat is leaking. Check for faulty fuel injector or
fuel pressure regulator. Repair as necessary.
9) When fuel pressure test is complete, repeat fuel pressure
release procedure before disconnecting fuel pressure gauge. Install
NEW "O" ring at end of high pressure fuel inlet line. Check for fuel
leaks.
FUEL PUMP PERFORMANCE TABLE
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At Idle w/Vacuum At Idle w/o Vacuum
Application psi (kg/cm) psi (kg/cm)
Eclipse 2.0L
Non-Turbo ........... ( 1) ............ 47-50 (3.3-3.5)
Turbo ............. 33 (2.3) ......... 42-45 (3.0-3.5)
3000GT Turbo ........ 34 (2.4) ......... 43-45 (3.0-3.1)
All Other Models .... 38 (2.7) ......... 47-50 (3.3-3.5)
( 1) - Information is not available from manufacturer at time
G - TESTS W/CODES
1998 Mitsubishi Montero
1998 ENGINE PERFORMANCE
Mitsubishi - Self-Diagnostics
Montero & 3000GT
INTRODUCTION
* PLEASE READ THIS FIRST *
NOTE: If no faults were found while performing basic diagnostic
procedures in F - BASIC TESTING article, proceed with
self-diagnostics in this article. If no Diagnostic Trouble
Codes (DTCs) or only pass codes are present after entering
self-diagnostics, proceed to H - TESTS W/O CODES article for
diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).
SYSTEM DIAGNOSIS
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.
System diagnosis can be accomplished using a scan tool. See
ENTERING ON-BOARD DIAGNOSTICS . Powertrain Control Module (PCM)
monitors several different engine control system circuits. If an
abnormal input signal occurs, a Diagnostic Trouble Code (DTC) is
stored in PCM memory and assigned a DTC number. Each circuit has its
own DTC number and message. A specific DTC indicates a particular
system failure, but does not indicate that cause of failure is
necessarily within system.
A DTC does not condemn any specific component; it simply
points out a probable malfunctioning area. If a DTC is set, PCM will
turn on MIL. System failures encountered are identified as either hard
failures or intermittent failures as determined by PCM.
Hard Failures
Hard failures cause MIL to come on and remain on until
failure is repaired. If MIL comes on and remains on (MIL may flash)
during vehicle operation, cause of failure may be determined by using
appropriate DTC diagnostic procedure. See TROUBLE CODE DEFINITION. If
a sensor fails, PCM will use a substitute value in its calculations to
continue engine operation. In this condition (limp-in mode), vehicle
is functional, but loss of good driveability may result.
Intermittent Failures
Intermittent failures may cause MIL to flicker, or come on
and go out after intermittent DTC goes away. However, corresponding
DTC will be retained in PCM memory. If related DTC does not reoccur
within a certain time frame, related DTC will be erased from PCM
memory. Intermittent failures may be caused by a sensor, connector or
wiring problems. See INTERMITTENTS in H - TESTS W/O CODES article.
The PCM also records and stores engine operating conditions
when malfunction occurred. This information is referred to as freeze
frame data. If malfunction is an engine misfire, or fuel system rich
or fuel system lean condition, freeze frame data will be updated with
the most current information regarding these failures. Freeze frame
data recorded is:
* Fuel System Status
* Load Value (Displayed As Percent)
* Engine Coolant Temperature
* Short Term Fuel Trim (Displayed As Percent)
* Long Term Fuel Trim (Displayed As Percent)
* MAP Vacuum
* Engine RPM
* Vehicle Speed Sensor
* DTC During Data Recording
SELF-DIAGNOSTIC SYSTEM
SERVICE PRECAUTIONS
Before proceeding with diagnosis, following precautions must
be observed:
* Ensure vehicle has a fully charged battery and functional
charging system.
* Visually inspect connectors and circuit wiring being worked
on.
* DO NOT disconnect battery or PCM. This will erase any DTCs
stored in PCM.
* DO NOT cause short circuits when performing electrical tests.
This will set additional DTCs, making diagnosis of original
problem more difficult.
* DO NOT use a test light in place of a voltmeter.
* When checking for spark, ensure coil wire is NOT more than
1/4" from chassis ground. If coil wire is more than 1/4" from
chassis ground, damage to vehicle electronics and/or PCM may
result.
* DO NOT prolong testing of fuel injectors. Engine may
hydrostatically (liquid) lock.
* When a vehicle has multiple DTCs, always repair lowest number
DTC first.
VISUAL INSPECTION
Most driveability problems in the engine control system
result from faulty wiring, poor electrical connections or leaking air
and vacuum hose connections. To avoid unnecessary component testing,
perform a visual inspection before beginning self-diagnostic tests.
ENTERING ON-BOARD DIAGNOSTICS
NOTE: DO NOT skip any steps in self-diagnostic tests or incorrect
diagnosis may result. Ensure self-diagnostic test applies to
vehicle being tested.
DTCs may be retrieved by using a scan tool only. Proceed to
DTC retrieval method.
NOTE: Although other scan tools are available, Mitsubishi
recommends using Multi-Use Tester II (MUT II) scan tool.
Using Scan Tool
1) Refer to manufacturer's operation manual for instructions
in use of scan tool. Before entering on-board diagnostics, see
SERVICE PRECAUTIONS . Locate Data Link Connector (DLC) under instrument
panel, near steering column.
2) Turn ignition switch to OFF position. Connect scan tool to
DLC. Turn ignition switch to ON position. Read and record scan tool
self-diagnostic output. Proceed to TROUBLE CODE DEFINITION.
TROUBLE CODE DEFINITION
When DTC is obtained, refer to appropriate DTC test
procedure.
DIAGNOSTIC TROUBLE CODES (DTCS)
NOTE: DTCs can only be retrieved by using a scan tool. Listed DTCs
are retrieved using a generic scan tool. MUT II scan tool
can be used, but it may not read all DTCs. DTCS listed are
not used on all vehicles.
DTC P0100
Volume Airflow (VAF) circuit failure. Possible causes are:
connector or harness, or faulty VAF sensor.
DTC P0105
Barometric (BARO) pressure circuit failure. Possible causes
are: connector or harness, or faulty BARO pressure sensor.
DTC P0105
Manifold Absolute Pressure (MAP) circuit failure. Possible
causes are: connector or harness, or faulty MAP sensor.
DTC P0110
Intake Air Temperature (IAT) circuit failure. Possible causes\
are: connector or harness, or faulty VAF sensor.
DTC P0115
Engine Coolant Temperature (ECT) circuit failure. Possible
causes are: connector or harness, or faulty ECT sensor.
DTC P0120
Throttle Position (TP) circuit failure. Possible causes are:
connector or harness, or faulty TP sensor.
DTC P0125
Excessive time to enter closed loop fuel control. Possible
causes are: faulty front HO2S, HO2S connector or harness, or faulty
fuel injector.
DTC P0130
Front Heated Oxygen Sensor (HO2S) circuit failure. Possible
causes are: connector or harness, or faulty HO2S.
DTC P0135
Front Heated Oxygen Sensor (HO2S) heater circuit failure.
Possible causes are: connector or harness, or faulty HO2S.
DTC P0136
Rear Heated Oxygen Sensor (HO2S) circuit failure. Possible
causes are: connector or harness, or faulty HO2S.
DTC P0141
Rear Heated Oxygen Sensor (HO2S) heater circuit failure.
Possible causes are: connector or harness, or faulty HO2S.
DTC P0150
Heated Oxygen Sensor (HO2S) circuit failure (bank 2, sensor
1). Possible causes are: connector or harness, or HO2S.
purge control valve, or vacuum hose routing.
DTC P0443
Evaporative (EVAP) purge control valve circuit failure.
Possible causes are: connector or harness, or faulty EVAP solenoid.
DTC P0446
Evaporative (EVAP) emission control system vent control
failure. Possible causes are: connector or harness, faulty EVAP vent
solenoid.
DTC P0450
Evaporative (EVAP) emission control system pressure sensor
failure. Possible causes are: connector or harness, or faulty fuel
tank differential pressure sensor.
DTC P0455
Evaporative (EVAP) emission control system large leak
detected. Possible causes are: connector or harness, faulty EVAP purge
solenoid, purge control valve, or vacuum hose routing.
DTC P0500
Vehicle Speed Sensor (VSS) failure. Possible causes are:
connector or harness, or faulty VSS.
DTC P0505
Idle Air Control (IAC) system failure. Possible causes are:
connector or harness, or faulty IAC motor.
DTC P0510
Closed Throttle Position (TP) switch failure. Possible causes\
are: connector or harness, or faulty closed TP switch.
DTC P0551
Power Steering Pressure (PSP) sensor failure. Possible causes\
are: connector or harness, or faulty PSP sensor.
DTC P0705
Automatic transaxle/transmission range sensor circuit
failure. Possible causes are: connector or harness, or faulty PNP
switch.
DTC P0710
Automatic transaxle/transmission fluid sensor failure.
Possible causes are: connector or harness, or faulty
transaxle/transmission sensor.
DTC P0715
Automatic transaxle input/turbine speed sensor circuit
failure. Possible causes are: connector or harness, or pulse
generator.
DTC P0720
Automatic transaxle input/turbine speed sensor circuit
failure. Possible causes are: connector or harness, or pulse
generator.
DTC P0725
Engine speed input circuit failure. Possible causes are:
connector or harness.
DTC P0740
Torque converter clutch system failure. Possible causes are:
connector or harness, or torque converter clutch solenoid.
DTC P0750
Shift solenoid "A" failure. Possible causes are: connector or
harness, or low-reverse solenoid.
DTC P0755
Shift solenoid "B" failure. Possible causes are: connector or
harness, or underdrive solenoid.
DTC P0760
Shift solenoid "C" failure. Possible causes are: connector or
harness, or second solenoid.
DTC P0765
Shift solenoid "D" failure. Possible causes are: connector or
harness, or overdrive solenoid.
DTC P1103
Turbocharger wastegate actuator failure. Possible causes are:
connector or harness, faulty wastegate solenoid or actuator, or vacuum
hose routing.
DTC P1104
Turbocharger wastegate solenoid failure. Possible causes are:
connector or harness, or faulty wastegate solenoid.
DTC P1105
Fuel pressure solenoid failure. Possible causes are:
connector or harness, or faulty fuel pressure solenoid.
DTC P1400
Manifold Differential Pressure (MDP) sensor circuit failure.
Possible causes are: connector or harness, or faulty MDP sensor.
DTC P1500
Generator FR terminal circuit failure. Possible causes are:
connector or harness.
DTC P1600
Serial communication link failure. Possible causes are:
connector or harness.
DTC P1715
Pulse Generator (PG) failure. Possible causes are: connector
or harness, or faulty PG.
DTC P1750
Solenoid failure. Possible causes are: connector or harness,
faulty converter clutch solenoid, shift control solenoid, or pressure
control solenoid.
DTC P0751
Automatic transaxle control relay failure. Possible causes
are: connector or harness, or automatic transaxle relay.
DTC P1791
Engine coolant temperature level input circuit (to TCM)
failure. Possible causes are: connector or harness.
DTC P1795
Throttle position input circuit failure. Possible causes are:
connector or harness.