Preliminary Inspection

WARNING: This page is about a different car, the 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, 2003 Chevrolet Monte Carlo, and 2003 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Manufacturer does not provide testing procedures for many individual systems and components. For system testing not listed, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.

Several of the symptom procedures call for a careful visual and physical inspection. This can lead to correcting a problem without further tests and can save valuable time. This inspection should include the following areas:

Verify on-vehicle diagnostics are working by performing diagnostic system check - engine controls. Go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO article.
Search for Technical Service Bulletins (TSBs).
Ensure PCM 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.
Remove the air filter element and check for dirt and for restrictions.
Inspect the air intake ducts for being collapsed, damaged areas, looseness, improper installation, or leaking, especially between the Mass Airflow (MAF) sensor and the throttle body.
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 PCM and MIL are functioning properly.
Ensure there are no DTCs stored, or only intermittent DTCs are present.
Ensure fuel control system is operating properly. Go to FUEL SYSTEM DIAGNOSIS in SYSTEM & COMPONENT TESTING - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO 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. These procedures will normally recommend testing of a specific system or component, such as EGR, ignition, TCC, etc. Go to SYSTEM & COMPONENT TESTING - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO article for appropriate test procedures.

NOTE: If PCM displays data but engine fails to start, go to NO-START DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO article.