Important Preliminary Checks Before Starting
Before using the Symptom tables use the following procedure:
- | Verify that diagnostic trouble codes (DTCs) are not stored. |
- | Verify that the scan tool data is within normal operating range.
Refer to
Scan Tool Data List
. |
• | Verify the customer complaint. |
• | Perform the Visual/Physical Check. |
Locate the correct symptom in the list at the end of this section. Follow
the procedures in the appropriate diagnostic table. If the presenting condition
can not be duplicated, or the condition is determined to be intermittent
refer to
Intermittent Conditions
.
Visual/Physical Check
Notice: Use the connector test adapter kit J 35616-A for any test that
requires probing the following items:
• | The PCM harness connectors |
• | The electrical center fuse/relay cavities |
• | The component terminals |
• | The component harness connector |
Using this kit will prevent damage caused by the improper probing of
connector terminals.
Several of the symptom procedures call for a careful visual
and physical inspection. This can lead to correcting a condition without
further tests and can save valuable time. This inspection should include
the following areas:
• | The vacuum hoses for splits, kinks, and proper connections--Compare
the connections to the data contained on the Vehicle Emission Control Information
label. Thoroughly inspect for any type of leak or restriction.
Refer to
Emission Hose Routing Diagram
. |
• | The air intake ducts--Inspect for the following conditions: |
- | Evidence of leaking, especially between the mass air flow (MAF)
sensor and the throttle body |
• | Air leaks at the throttle body mounting area, MAF sensor and intake
manifold sealing surfaces |
• | The wiring harness for poor connections, pinches, cuts, or other
damage |
• | Loose, damaged, or missing sensors and components. |
Use the following tables when diagnosing a symptom complaint: