Nissan Note — диагностика неисправностей двигателя: основные рекомендации [491/1872]

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TROUBLE DIAGNOSIS

EC-491

[CR (WITHOUT EURO-OBD)]

TROUBLE DIAGNOSIS PFP:00004

Trouble Diagnosis Introduction

BBS0035B

INTRODUCTION

The engine has an ECM to control major systems such as fuel con-

trol, ignition control, idle air control system, etc. The ECM accepts

input signals from sensors and instantly drives actuators. It is essen-

tial that both input and output signals are proper and stable. At the

same time, it is important that there are no malfunctions such as vac-

uum leaks, fouled spark plugs, or other malfunctions with the engine.

It is much more difficult to diagnose an incident that occurs intermit-

tently rather than continuously. Most intermittent incidents are

caused by poor electric connections or improper wiring. In this case,

careful checking of suspected circuits may help prevent the replace-

ment of good parts.

A visual check only may not find the cause of the incidents. A road

test with CONSULT-II or a circuit tester connected should be per-

formed. Follow the Work Flow on EC-492

Before undertaking actual checks, take a few minutes to talk with a

customer who approaches with a driveability complaint. The cus-

tomer can supply good information about such incidents, especially

intermittent ones. Find out what symptoms are present and under

what conditions they occur. A Diagnostic Worksheet like the example

on EC-496

should be used.

Start your diagnosis by looking for conventional malfunctions first.

This will help troubleshoot driveability malfunctions on an electroni-

cally controlled engine vehicle.

MEF036D

SEF233G

SEF234G