Important Preliminary Checks
Before Starting
Before using this section, perform the 
Diagnostic System Check - Vehicle 
 in Vehicle DTC Information and verify all of the
following conditions:
|     •  | The powertrain control module (PCM), malfunction indicator lamp (MIL),
 and check engine are operating correctly. | 
 
|     •  | There are no diagnostic trouble codes (DTCs) stored. | 
 
Verify the customer complaint, and locate the correct symptom in the table of
 contents. Check the items indicated under that symptom.
Visual/Physical Check
Several of the symptom procedures call for a careful visual/physical check.
 The importance of this step cannot be stressed strongly enough. This step can lead
 to correcting a problem without further checks and can save valuable time. This check
 should include:
|     •  | PCM grounds for the following conditions: | 
 
|     •  | Vacuum hoses for the following conditions: | 
 
|     •  | Air leaks at the following components: | 
 
|        -  | Intake manifold sealing surfaces | 
 
|     •  | Wiring for the following conditions: | 
 
|     •  | Use the following tables when diagnosing a symptom complaint: |