Section 231 (Engine Controls - System Testing & Engine Component Tests - 3.1L): Introduction
WARNING: This page is about a different car, the 2003 Pontiac Grand Prix, 2003 Chevrolet Malibu, and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
Before testing separate components or systems, follow proper workflow. See DIAGNOSTIC STARTING POINT - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 3.1L CENTURY, GRAND PRIX & MALIBU article. If no Diagnostic Trouble Codes (DTC) are present and a no-start condition exists, proceed to BASIC DIAGNOSTIC PROCEDURES - 3.1L CENTURY, GRAND PRIX & MALIBU article. If no DTCs are present and a driveability condition exists, proceed to TROUBLE SHOOTING - NO CODES - 3.1L CENTURY, GRAND PRIX & MALIBU article for diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).
NOTE:
Testing individual components does not isolate shorts or opens. Perform all voltage tests using a DVOM with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.