Engine Controls - System/Component Tests: Introduction
Before testing separate components or systems, perform procedures in BASIC TESTING article in this section. Since many computer-controlled and monitored components set a trouble code if they malfunction, also perform procedures in the appropriate article below:
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 and refer to WIRING DIAGRAMS to isolate wiring harness shorts or opens.
NOTE:
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 - USING THIS SECTION (GENERAL HELP INFORMATION) in this section.
GENERAL MOTORS "A" & "C" CHART REFERENCE
| System or Component | Diagnostic Information Location | ||||
|---|---|---|---|---|---|
| DIAGNOSTIC CIRCUIT CHECK | See DIAGNOSTIC CIRCUIT CHECK in BASIC TESTING in this section | ||||
| A-1 & A-2, SERVICE ENGINE SOON Light | See DIAGNOSTIC CIRCUIT CHECK in BASIC TESTING in this section | ||||
| A-3, No-Start | See NO-START DIAGNOSIS in BASIC TESTING in this section | ||||
| A-5, Fuel Pump Relay | See RELAYS, SOLENOIDS, MOTORS & MODULES in this article | ||||
| A-7, Fuel System Diagnosis | See BASIC FUEL SYSTEM CHECKS in BASIC TESTING in this section | ||||
| C-1, MAP Sensor | See ENGINE SENSORS & SWITCHES in this article | ||||
| C-1, Power Steering Pressure Switch | See ENGINE SENSORS & SWITCHES in this article | ||||
| C-1, Park/Neutral Switch | See ENGINE SENSORS & SWITCHES in this article | ||||
| C-2, Injector Balance Test (4.3L) | See FUEL CONTROL in this article | ||||
| C-2, IAC Motor | See IDLE CONTROL SYSTEM in this article | ||||
| C-3, Canister Purge System | See EMISSION SYSTEMS & SUB-SYSTEMS in this article | ||||
| C-4, EST Ignition Check | See BASIC IGNITION SYSTEM CHECKS in this article | ||||
| C-5, ESC Ignition Check | See IGNITION SYSTEM in this article | ||||
| C-6, Air Injection System | See EMISSION SYSTEMS & SUB-SYSTEMS in this article | ||||
| C-7, EGR System | See EMISSION SYSTEMS & SUB-SYSTEMS in this article | ||||
| C-8, Torque Converter Clutch | See MISCELLANEOUS ECM CONTROLS in this article | ||||
| C-8, Manual Transmission Shift Lights | See MISCELLANEOUS ECM CONTROLS in this article | ||||
| C-10, A/C Clutch Control | (1) See MISCELLANEOUS ECM CONTROLS in this article | ||||
| C-12, Electric Cooling Fan Control | (2) See MISCELLANEOUS ECM CONTROLS in this article | ||||
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