1998 MITSUBISHI MONTERO Service Manual

Fig. 10: Charging System Wiring Diagram (Montero)

Fig. 11: Charging System Wiring Diagram (Montero Sport)

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

indicates a fault has been located.
Use a DVOM to pinpoint faults. See J - PIN VOLTAGE CHARTS
article. When monitoring voltage, ensure ignition switch is in ON
position or engine is running. Ensure ignition switch is in OFF
position when monitoring circuit resistance. Status changes on DVOM
during test procedures indicate area of fault.
TEST PROCEDURES
Intermittent Simulation
To reproduce conditions creating an intermittent fault, use
following methods:
* Lightly vibrate component.
* Heat component.
* Wiggle or bend wiring harness.
* Spray component with water mist.
* Remove/apply vacuum source.
Monitor circuit/component voltage or resistance while
simulating intermittent fault. If engine is running, monitor for
diagnostic trouble codes. Use test results to identify a faulty
component or circuit.

HEATER SYSTEM
1998 Mitsubishi Montero
1998 AIR CONDITIONING & HEAT
Mitsubishi - Heater System
Montero
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article.
DESCRIPTION
Heater assembly is located in passenger compartment. A heater
control valve is used to regulate coolant flow and heat output. Heater
assembly contains heater core, heater control valve, air ducts, blower
motor and intake ducts. See Fig. 1. Heater systems are blend-air type.
OPERATION
Heater and fresh air operations are controlled by control
knobs and/or levers, which regulate airflow source, temperature
setting, airflow direction and blower speed.
Fig. 1: Exploded View Of Front Heater System Components
Courtesy of Mitsubishi Motor Sales of America.
FRONT AIR SELECTOR LEVER

This lever is used to select source of airflow. With lever at
fresh air setting, outside air is allowed to enter and/or pass through
heater. With lever at recirculated air setting, air is recirculated
inside passenger compartment.
FRONT BLOWER SWITCH
Front blower switch controls fan speeds to regulate amount of
airflow. Fan speed increases as switch is turned/moved to far right.
COOL AIR BY-PASS KNOB
With heater in floor, defrost/floor or defrost mode, turning
knob to far left allows cool air to enter passenger compartment
through center vent.
FRONT MODE SELECTOR KNOB/LEVER
Depending on position selected, airflow can be directed to
different areas of passenger compartment. Airflow selection
capabilities include individual areas or a combination of windshield,
upper body, knee and/or foot area.
TEMPERATURE CONTROL
Temperature control is adjusted by moving control lever or
turning control knob to left or right. Temperature control cable opens
and closes heater control valve, which determines heat output. Highest
heat setting is attained when lever/knob at far right position. With
temperature lever/knob at cool setting, ambient air is used for
ventilating.
ADJUSTMENTS
FRONT FRESH/RECIRCULATED AIR SELECTOR CABLE
Place air selector lever at recirculated air setting. Press
damper lever inward, in direction of arrow. See Fig. 2. Connect inner
wire of fresh/recirculated air selector cable to damper lever. Secure
outer wire of selector cable with clip.
Fig. 2: Adjusting Front Fresh/Recirculated Air Selector Cable
Courtesy of Mitsubishi Motor Sales of America.
FRONT MODE SELECTOR CABLE