Preliminary Inspection

• Verify on-vehicle diagnostics are working by performing DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 3.0L SATURN "L" SERIES article.
• Ensure ECM grounds are clean, tight, and properly located.
• Check vacuum hoses for splits, kinks, leaks, restrictions and proper connections. Ensure vacuum hoses are correctly routed as shown on vehicle emission control information label.
• Check for air leaks at all intake manifold sealing surfaces.
• Check ignition wires for cracking, hardness, proper routing and carbon tracking.
• Check wiring for proper connections and routing, pinches, burns, cuts or other damage.
• Ensure ECM and MIL are functioning properly.
• Ensure there are no DTCs stored, or only intermittent DTCs are present.
• Perform fuel system pressure test and ensure fuel control system is operating properly. See FUEL SYSTEM DIAGNOSIS under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES - 3.0L SATURN "L" SERIES article.
• Perform a careful visual inspection of all systems.

After all checks have been performed, verify customer complaint and locate correct symptom. Check items indicated under that symptom. Not all items listed under each symptom apply to all models and systems. These procedures will normally recommend testing of a specific system or component, such as EGR, ignition, TCC, etc. See SYSTEM & COMPONENT TESTING - 3.0L SATURN "L" SERIES article.