Mitsubishi Montero (1998+). Manual — part 199

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.