Visual and Physical Underhood Inspection

One of the most important checks is a visual and physical underhood inspection. This can often fix a problem. These quick checks take only a few minutes, can save valuable time, and help you to correct the problem. For further information, refer to Symptoms. Symptom Related Diagnostic Procedures

All powertrain diagnosis should begin with a thorough visual inspection. Visual inspection can often lead to repair of a simple problem without use of the tables.
^ Inspect all vacuum hoses for being pinched, cut, disconnected, or misrouted. The EVAP purge solenoid vacuum hoses can easily be installed incorrectly. Be sure to inspect hoses that are difficult to see such as those beneath the upper intake, the generator, etc.
^ Check for good ground connections, ground eyelets connections to ground points, and star washer installation, if applicable.
^ Check the battery positive junction block for loose retainer nuts.
^ Inspect other wiring in the engine compartment for good connections, burned or chaffed spots, pinched wires, or harness contact with sharp edges or hot exhaust manifolds.
^ Check for open or missing fuses and for relays missing or installed in the wrong locations.