Mitsubishi Montero (1991+). Manual — part 210

Fig. 11: Squeak, Rattle, & Noise Conditions

Fig. 12: Water Leak & Wind Noise

I - SYSTEM/COMPONENT TESTS

1991 Mitsubishi Montero

1991 ENGINE PERFORMANCE

System & Component Testing

Chrysler Motors: Ram-50

Mitsubishi: Montero, Pickup

INTRODUCTION

Before testing separate components or systems, perform

procedures in F - BASIC TESTING article in the ENGINE PERFORMANCE

Section. Since many computer controlled and monitored components set a

trouble code if they malfunction, also perform procedures in G - TESTS

W/CODES article in the ENGINE PERFORMANCE Section.

NOTE: Testing individual components does not isolate shorts or

opens. Perform all voltage tests with a Digital

Volt-Ohmmeter (DVOM) with a minimum 10-megohm input

impedance, unless stated otherwise in test procedure. Use

ohmmeter to isolate wiring harness shorts or opens.

COMPUTERIZED ENGINE CONTROLS

CONTROL UNIT

NOTE: To identify ECU power and ground circuits, see appropriate

L - WIRING DIAGRAMS article in the ENGINE PERFORMANCE

Section.

Ground Circuits

1) ECU is located near right kick panel. Turn ignition off.

Using an ohmmeter, check for continuity between ground and ECU

terminals No. 101 and 106. Resistance should be zero ohms. If

resistance is not zero ohms, repair open circuit between ECU connector

and ground.

2) Connect voltmeter negative lead to ground. Connect

positive lead to ECU ground terminals as in step 1). With vehicle

running, voltmeter should indicate less than one volt. If voltmeter

reading is greater than one volt, check for open, corrosion or loose

connection in ground circuit.

Power Circuits

ECU is located near right kick panel. Turn ignition on. Check

for battery voltage on ECU terminals No. 102 and 107. If battery

voltage is not present, check operation of MPI control relay. See

RELAYS under MOTORS, RELAYS & SOLENOIDS.

ENGINE SENSORS & SWITCHES

BAROMETRIC PRESSURE SENSOR

Sensor is a component part of airflow sensor assembly. See G

- TESTS W/CODES article in the ENGINE PERFORMANCE Section.

COOLANT TEMPERATURE SENSOR

1) Remove coolant temperature sensor located near thermostat

housing (2-wire connector). Place end of sensor in water with terminal

connector portion of sensor slightly above water.

2) Gradually heat water and read resistance values across

terminal connectors. See COOLANT TEMPERATURE SENSOR RESISTANCE table.

If resistance is not within specification, replace sensor.

COOLANT TEMPERATURE SENSOR RESISTANCE TABLE

Temperature

F (

C) Ohms

Montero & Pickup 3.0L

32 (0) . . . . . . . . 5900

68 (20) . . . . . . . 2500

104 (40) . . . . . . ... 2700

176 (80) . . . . . . . 300

All Others

32 (0) . . . . . . . . 5900

68 (20) . . . . . . . 2500

104 (40) . . . . . . ... 1100

176 (80) . . . . . . . 300

CRANK ANGLE SENSOR

See IGNITION SYSTEM.

DETONATION SENSOR

See IGNITION SYSTEM.

EGR TEMPERATURE SENSOR

California

See EXHAUST GAS RECIRCULATION (EGR) under EMISSION SYSTEMS &

SUB-SYSTEMS.

IDLE POSITION SWITCH

NOTE: Idle position switch is incorporated in idle speed control

motor assembly, motor position sensor or throttle position

sensor, depending upon vehicle application.

Pickup 2.4L & Ram-50 2.4L

1) Disconnect motor position sensor (MPS) connector. Connect

ohmmeter lead between ground and MPS connector terminal No. 4. See

Fig. 2.

2) With accelerator pedal pressed, no continuity should be

present. With accelerator pedal released, continuity should be

present. If switch continuity is not as specified, replace MPS.

Montero, Pickup 3.0L & Ram-50 3.0L

1) Disconnect throttle position sensor (TPS) connector.

Connect ohmmeter between TPS connector terminals No. 1 and 2. See

Fig. 6.

2) With accelerator pedal pressed, no continuity should be

present. With accelerator pedal released, continuity should be

present. If idle switch continuity is not as specified, replace TPS.

INHIBITOR SWITCH

Automatic Transmission

Switch is mounted to automatic transaxle, near shift lever