Visual Inspection
Most driveability problems in the engine control system result from faulty wiring, poor electrical connections, improper wire routing, or leaking air and vacuum hose connections. Always perform a visual inspection before attempting to diagnose engine control system problems. Inspect all engine control system components, hoses, connectors and wiring for damage before proceeding with system testing. Make repairs as necessary. After completing visual inspection, retrieve Diagnostic Trouble Codes (DTC). See RETRIEVING DIAGNOSTIC TROUBLE CODES .