Diagnostic Aids

WARNING: This page is about a different car, the 2003 GMC Savana and 2003 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.

Inspect the FICM for the proper part number. Bi-Fuel (KL6) and dedicated (KL8) CNG equipped vehicles utilize unique FICM's that are not interchangeable.
Use a scan tool in order to review Failure Records. If an intermittent condition is suspected, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.