1998 MITSUBISHI MONTERO engine coolant

continuity between chassis ground and EGR solenoid connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, condition required to set DTC is not
present at this time. Go to next step.
12) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P0420, P0421 & P0431: CATALYST EFFICIENCY BELOW
THRESHOLD
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
Specific self-diagnostic test not available from manufacturer
at time of publication. Check catalytic converter and check for
cracked exhaust manifold. Also, see F - BASIC TESTING article.
DTC P0442: EVAPORATIVE (EVAP) EMISSION CONTROL SYSTEM LEAK
DETECTED
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Remove fuel cap. Push fuel pipe restrictor to operate On-
board Fuel Vent Valve (OFLV). Install and tighten fuel cap. Remove
fuel cap and ensure distance between filler tube and OFLV is 1.1" (28
mm). If distance is as specified, go to next step. If distance is not
as specified, replace fuel tank filler tube assembly. Go to step 24).
2) Disconnect and plug air filter-to-EVAP vent solenoid hose
at air filter. Disconnect intake manifold plenum-to-EVAP purge
solenoid at intake manifold plenum. Install a "T" fitting between
vacuum hose and intake manifold plenum. Connect a hand-held
pressure/vacuum pump to "T" fitting. Go to next step.
CAUTION: DO NOT apply more than 0.57 psi in following step. Applying
more than specified psi can crack fuel tank.
NOTE: Ensure fuel tank is at least 1/4 full. The lower the fuel
level in fuel tank, the longer it takes to pressurize fuel
system.
3) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, go to next step. If
reading does not reach 0.42 psi, go to step 9).
4) Wait 20 seconds and read scan tool. If scan tool reading
increases 0.06 psi or less, go to next step. If scan tool reading
increases more than 0.06 psi, go to step 21).
5) Disconnect EVAP canister purge hose. Connect Purge Flow
Indicator (MB995061) between EVAP canister and disconnected hose. Turn\
engine on and allow it to reach operating temperature. Turn all lights
and accessories off. Place transmission in Park or Neutral. Observe
purge flow indicator while increasing engine RPM several times. If
purge flow indicator reads less than 2.5 SCFH (20 cm(3)/sec), check
EVAP canister purge hose and EVAP canister port for clogging. If hose
and port are okay, check EVAP purge solenoid. See DTC P0443. If
solenoid is okay, replace EVAP canister. Go to step 24).
6) Using scan tool, read Engine Coolant Temperature (ECT)
sensor temperature (item 21). Compare scan tool reading with

system.
3) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, go to next step. If
reading does not reach 0.42 psi, go to step 8).
4) Disconnect EVAP canister purge hose. Connect Purge Flow
Indicator (MB995061) between EVAP canister and disconnected hose. Turn\
engine on and allow it to reach operating temperature. Turn all lights
and accessories off. Place transmission in Park or Neutral. Observe
purge flow indicator while increasing engine RPM several times. If
purge flow indicator reads less than 2.5 SCFH (20 cm(3)/sec), check
EVAP canister purge hose and EVAP canister port for clogging. If hose
and port are okay, check EVAP purge solenoid. See DTC P0443. If
solenoid is okay, replace EVAP canister. Go to step 20).
5) Using scan tool, read Engine Coolant Temperature (ECT)
sensor temperature (item 21). Compare scan tool reading with
temperature gauge reading. If readings are about the same, go to next
step. If readings are not about the same, go to DTC P0115 test.
6) Using a thermometer, check engine compartment ambient
temperature. Using scan tool, read Intake Air Temperature (IAT) sensor\
temperature (item 13). Compare IAT sensor and thermometer readings. If\
readings are not about the same, go to DTC P0110 test. If readings are
about the same, go to next step.
7) Using scan tool, read Power Steering Pressure (PSP) switc\
h
status (item 27). Switch status should read ON when steering wheel is
turned. If switch status is as specified, go to step 20). If switch
status is not as specified, go to DTC P0551 test.
8) Remove fuel cap. Install a fuel tank filler tube adapter
in place of fuel cap. Plug fuel filler tube adapter hose. Disconnect
and plug air filter-to-EVAP vent solenoid hose at air filter.
Disconnect intake manifold plenum-to-EVAP purge solenoid at intake
manifold plenum. Install a "T" fitting between vacuum hose and intake
manifold plenum. Connect hand-held pressure/vacuum pump to "T"
fitting. Go to next step.
CAUTION: DO NOT apply more than 0.57 psi in following step. Applying
more than specified psi can crack fuel tank.
NOTE: Ensure fuel tank is at least 1/4 full. The lower the fuel
level in fuel tank, the longer it takes to pressurize fuel
system.
9) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, replace fuel cap. Go
to step 20). If reading does not reach 0.42 psi, go to next step.
10) Disconnect hand-held pressure/vacuum pump from "T"
fitting. Install an evaporative emission system tester in place of
vacuum held pump and apply 0.49 psi. Wait two minutes. If pressure
drops less than 0.20 psi, go to next step. If pressure drops 0.29 psi
or more, go to step 13).
11) Disconnect EVAP purge solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose and
apply 0.9 psi. If pressure is not maintained, check EVAP purge
solenoid for leak. If EVAP purge solenoid is okay, replace hose. Go to
step 24). If pressure is maintained, go to next step.
12) Disconnect EVAP vent solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose and
apply 0.9 psi. If pressure is not maintained, check EVAP vent solenoid
for leak. If EVAP vent solenoid is okay, replace hose. Go to step 20).
If pressure is maintained, replace EVAP canister. Go to step 24).
13) Ensure hoses are properly routed and connected. See M -

wiring harness as necessary. If continuity exists, go to next step.
5) Reconnect PCM connector. Turn ignition switch to ON
position. Check voltage between chassis ground and MDP sensor
connector terminal No. 3. If voltage is not 4.8-5.2 volts, replace
PCM. If voltage is as specified, condition required to set DTC is not
present at this time. Go to next step.
6) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P1600: SERIAL COMMUNICATION LINK MALFUNCTION
DTC P1600 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1715: PULSE GENERATOR FAILURE
DTC P1715 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1750: SOLENOID FAILURE
DTC P1750 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1791: ENGINE COOLANT TEMPERATURE LEVEL INPUT TO TCM
DTC P1791 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
SUMMARY
If no hard DTCs (or only pass DTCs) are present, driveability\
symptoms exist, or intermittent DTCs exist, proceed to H - TESTS W/O
CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START,
etc.) or intermittent diagnostic procedures.

REFILLING
To prevent air from being trapped in engine block, engine
should be running when refilling cooling system. After system is full,
continue running engine until thermostat is open, then recheck fill
level. Do not overfill system.
TESTING
THERMOSTAT
1) Visually inspect thermostat for corrosion and proper
sealing of valve and seat. If okay, suspend thermostat and thermometer
in a 50/50 mixture of coolant and water. See Fig. 1. Do not allow
thermostat or thermometer to touch bottom of container. Heat water
until thermostat just begins to open.
2) Read temperature on thermometer. This is the initial
opening temperature and should be within specification. Continue
heating water until thermostat is fully open and note temperature.
This is the fully opened temperature. If either reading is not to
specification, replace thermostat.
Fig. 1: Testing Thermostat in Anti-Freeze/Water Solution
PRESSURE TESTING
A pressure tester is used to check both radiator cap and

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.

* 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.

* 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

Brake On/Off (BOO) Switch ................... Cruise Control Systems\
Engine Performance
Shift Interlock Systems
Buzzer Module ...................................... Warning Systems
Camshaft Position (CMP) Sensor .................. Engine Performance\
Central Control Module ........................... Anti-Theft System
Clockspring ............................... Air Bag Restraint System
Cruise Control Systems
Steering Column Switches
Clutch Pedal Position Switch .............................. Starters
Clutch Start Switch ....................................... Starters
Combination Meter ......................... Analog Instrument Panels
Constant Control Relay Module (CCRM) ............ Engine Performance\
Electric Cooling Fans
Convenience Center .............................. Power Distribution
Illumination/Interior Lights
Convertible Top Motor ........................ Power Convertible Top
Convertible Top Switch ....................... Power Convertible Top
Crankshaft Position (CKP) Sensor ................ Engine Performance\
Cruise Control Module ....................... Cruise Control Systems
Cruise Control Switch ....................... Cruise Control Systems
Condenser Fan Relay(s) ....................... Electric Cooling Fans\
Data Link Connector (DLC) ....................... Engine Performance\
Daytime Running Lights Module ............... Daytime Running Lights
Exterior Lights
Defogger Relay ................................ Rear Window Defogger
Diagnostic Energy Reserve Module (DERM) ... Air Bag Restraint System\
Discriminating Sensor (Air Bag) ........... Air Bag Restraint System\
Distributor ..................................... Engine Performance
Door Lock Actuators ............................... Power Door Locks
Remote Keyless Entry
Door Lock Relay(s) ................................ Power Door Locks\
Electrochromic Mirror ................................ Power Mirrors
Electronic Level Control (ELC)
Height Sensor .............................. Electronic Suspension
Electronic Level Control (ELC) Module ........ Electronic Suspension\
Engine Coolant Temperature (ECT)
Sending Unit ............................ Analog Instrument Panels
Engine Coolant Temperature (ECT) Sensor ......... Engine Performance\
Engine Control Module ........................... Engine Performance
Generators & Regulators
Starters
ETACS ECU .......................................... Warning Systems
Power Windows
Remote Keyless Entry
Evaporative (EVAP) Emissions Canister ........... Engine Performance\
EVAP Canister Purge Solenoid .................... Engine Performance
EVAP Canister Vent Solenoid ..................... Engine Performance
Exhaust Gas Recirculation (EGR) Valve ........... Engine Performance\
Fuel Tank Vacuum Sensor ......................... Engine Performance
Fog Lights ....................................... Headlight Systems
Daytime Running Lights
Fog Light Relay .................................. Headlight Systems
Daytime Running Lights
Fuel Door Release Solenoid ................. Power Fuel Door Release
Fuel Gauge Sending Unit ................... Analog Instrument Panels
Fuel Injectors .................................. Engine Performance
Fuel Pump ....................................... Engine Performance
Fuel Pump Relay ................................. Engine Performance
Power Distribution
Fuse/Relay Block ................................ Power Distribution
Fusible Links ................................... Power Distribution
Generators & Regulators