Preliminary Inspection
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Savana, 2003 Chevrolet Silverado, and 2003 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
- Verify on-board diagnostics are working by performing DIAGNOSTIC SYSTEM CHECK - ALTERNATIVE FUELS - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 6.0L SILVERADO & SIERRA - BI-FUEL & CNG article or DIAGNOSTIC SYSTEM CHECK - ALTERNATIVE FUELS - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 6.0L CHEVY EXPRESS & SAVANA - BI-FUEL & CNG article.
- Ensure PCM and MIL functions properly.
- Ensure no DTCs (except intermittent) are stored.
- Perform fuel system pressure test. See FUEL SYSTEM PRESSURE TEST under FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 6.0L CHEVY EXPRESS, SAVANA, SIERRA & SILVERADO - BI-FUEL & CNG article.
- Visually inspect all systems.
After all checks have been performed, verify customer complaint and locate correct symptom. Check items indicated under that symptom. See SYMPTOMS .