Engine Controls - System & Component Testing: Introduction

Before testing separate components or systems, perform procedures in BASIC DIAGNOSTIC PROCEDURES article. Since many computer-controlled and monitored components set Diagnostic Trouble Code (DTC) if they malfunction, also perform procedures in appropriate SELF-DIAGNOSTICS article.

NOTE: On Accord, Odyssey and Prelude models, when substituting a known-good PCM, a temporary ignition key must be used or engine will not start. See SUBSTITUTING PCM in SELF-DIAGNOSTICS - INTRODUCTION article. When replacing PCM, immobilizer code must be rewritten to replacement PCM using Honda PGM tester or engine will not start.

NOTE: For testing and diagnosis of Variable Valve Timing (VTEC) system, see DTC P1253 or DTC P1259 in appropriate SELF-DIAGNOSTICS article.

NOTE: Before disconnecting battery, obtain anti-theft code for radio. After battery is reconnected, CODE will appear on radio display. Enter appropriate code. Any time radio power is lost, pre-selected radio stations will have to be set. For more information, see owner's manual.

NOTE: Perform all voltage tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Testing individual components does not isolate shorts or opens. Use ohmmeter to isolate wiring harness shorts or opens.