Important Preliminary Checks
Before Starting
Before using this section, you should have performed the Diagnostic
System Check-Engine Controls and determined that the following items
are OK:
• | 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: |
- | Proper connections as shown on Vehicle Emission Control Information
label |
• | Air leaks at the following components: |
- | Intake manifold sealing surfaces |
• | Wiring for the following conditions: |
• | Use the following tables when diagnosing a symptom complaint: |