GM Lumina/Silhouette/Transport APVs 1990-1999 Repair Guide



The fuel injection system is operated along with the ignition system to obtain optimum performance and fuel economy while producing a minimum of exhaust emissions. There are various sensors used by the computer control module for feedback to determine proper engine operating conditions.

When dealing with the electronic engine control system, keep in mind that the system is sensitive to improperly connected electrical and vacuum circuits. The condition and connection of all hoses and wires should always be the first step when attempting to diagnose a driveability problem. Worn or deteriorated hoses and damaged or corroded wires may well make a good component appear faulty.

Diagnosis of the electronic control systems used in today's vehicles requires some special tools. To diagnose the on-board systems used in these vehicles, a TECH 1®(or equivalent) scan tool will be necessary. If the proper tester is not available, the vehicle should be taken to a reputable service facility that has the appropriate equipment.