Subsystem Checks

Before using trouble shooting section, perform DIAGNOSTIC CIRCUIT CHECK to determine that ECM and "CHECK ENGINE" light are working properly. This also determines that there are no stored trouble codes, or that there is trouble code but no "CHECK ENGINE" light.

Fuel control system is operating properly by performing "Field Service Mode" check of DIAGNOSTIC CIRCUIT CHECK. Verify customer complaint. If "engine cranks but will not run", see CHART A-3 in COMPUTERIZED ENGINE CONTROL section.

Before testing fuel injection system for cause of malfunction, check that following subsystems and components are in good operating condition:

• Battery and charging system.
• Engine state of tune.
• Emission control devices.
• Fuel system pressure and delivery volume.
• Wiring connectors at components.
• Vacuum hoses for splits, kinks and proper connections.
• Air leaks at throttle body mounting and intake manifold.