Preliminary Checks

Most driveability problems in the engine control system result from faulty or poor wiring, or loose and/or leaking hose connections. To avoid unnecessary component testing, a visual check should be performed before beginning trouble shooting procedures to help spot these common faults. A preliminary visual check should include:

• Air ducts to air cleaner and from air cleaner to throttle body.
• Electrical connections at all components. Clean, tight and unbroken. Check vacuum lines for secure, leak-free connections in these areas:
• Throttle body (2 front, 2 rear).
• EGR and purge solenoids (located on a common bracket at right rear corner of engine compartment).
• Vapor canister.
• PCV valve to intake manifold vacuum port.
• Back pressure transducer.
• MAP sensor.

Ensure that the following electrical connectors are securely attached:

• 21-way connectors (2) at logic module (Black connector to Black socket, Tan connector to Tan socket).
• 3-way connector at MAP sensor.
• 3-way and 1-way connectors at ASD Relay.
• 12-way and 10-way connectors at power module.
• 3-way connector at EGR and purge solenoids.
• 2-way connector at speed sensor (located in line with speedometer cable).
• 6-way connector at AIS motor and TPS (and ground wire to manifold).
• 2-way connector at fuel injector.
• O2 connector.
• 2-way connector at coolant temperature sensor.
• 3-way connector at distributor.
• 4-way and 1-way connector at radiator fan relay.