Engine Controls - System/Component Tests: Introduction

Before testing separate components or systems, perform all procedures listed in BASIC TESTING article in this section. Since many computer-controlled and monitored components will set a diagnostic trouble code if they malfunction, it is also recommended that self-diagnosis be performed. See appropriate TESTS W/CODES article in this 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. The following table provides the location of commonly used diagnostic information. These former "A" and "C" charts are now written in text and inserted into the appropriate location in the new Engine Performance workflow. To familiarize yourself with the Engine Performance workflow, see AA - HOW TO USE THE ENGINE PERFORMANCE SECTION article in this section.

GENERAL MOTORS A & C CHART REFERENCE

System Or Component

Diagnostic Information Location

A-1 & A-2, MALFUNCTION INDICATOR LIGHT (MIL)

⁽¹⁾ See DIAGNOSTIC CIRCUIT CHECK

A-3, No Start

⁽¹⁾ See NO START - ENGINE CRANKS OKAY

A-5, Fuel Pump Relay

See FUEL SYSTEM in this article

A-7, Fuel System Diagnosis

⁽¹⁾ See BASIC FUEL SYSTEM CHECKS

C-1, ECM/PCM Replacement Check

⁽¹⁾ See ECM/PCM REPLACEMENT CHECK

C-1, MAP Sensor

See ENGINE SENSORS & SWITCHES in this article

C-1, Power Steering Pressure Switch

See ENGINE SENSORS & SWITCHES

C-1, Park/Neutral Position Switch

See ENGINE SENSORS & SWITCHES

C-2, Injector Balance Test

See FUEL SYSTEM

C-2, Injector Coil Test

See FUEL SYSTEM

C-2, Injector Leak Test

See FUEL SYSTEM

C-2, IAC Motor

See IDLE CONTROL SYSTEM

C-2, ISC Motor

See IDLE CONTROL SYSTEM

C-3, Canister Purge System (Fuel Evap Control)

See EMISSION SYSTEMS & SUB-SYSTEMS

C-4, EST Ignition Check

See BASIC IGNITION SYSTEM CHECKS

C-5, KS Ignition Check

See IGNITION SYSTEM

C-6, Air Injection System

See EMISSION SYSTEMS & SUB-SYSTEMS

C-7, EGR System

See EMISSION SYSTEMS & SUB-SYSTEMS

C-8, M/T Shift Lights

See MISCELLANEOUS CONTROLS

C-8, Torque Converter Clutch

⁽²⁾ See MISCELLANEOUS CONTROLS

C-10, A/C Clutch Control

See MISCELLANEOUS CONTROLS

C-12, Electric Cooling Fan Control

See MISCELLANEOUS CONTROLS

C-16, Engine Coolant Level Switch

See ENGINE SENSORS & SWITCHES

C-16, Fuel Pump/Oil Pressure Switch

See ENGINE SENSORS & SWITCHES

C-16, Oil Level Switch

See ENGINE SENSORS & SWITCHES

C-18, Supercharger Boost Control

See AIR INDUCTION SYSTEMS

⁽¹⁾	See BASIC TESTING article in this section.

⁽²⁾	Covered in entirety in TRANSMISSION SERVICING - A/T article in the AUTOMATIC TRANS SERVICE section.