Important Preliminary Checks Before Starting
Before using the Symptom tables use the following:
| - | Ensure no DTCs are stored. |
| • | Verify the customer complaint. |
| • | Perform the Visual/Physical Check in this section. |
Locate the correct symptom in the list at the end of this section. Follow
the procedures in the appropriate diagnostic table. If the problem can not
be duplicated, or is determined to be intermittent, refer to
Intermittent Conditions
.
Visual/Physical Check
Several of the symptom procedures call for a careful visual and physical
inspection. This can lead to correcting a problem without further
tests and can save valuable time. This inspection should include the
following areas:
| • | Inspect the PCM grounds for being clean, tight, and in their
proper location. |
| • | Inspect vacuum hoses for splits, kinks, and proper connections,
as shown on Vehicle Emission Control Information label. Inspect thoroughly
for any type of leak or restriction. |
| • | Inspect the air intake ducts for being collapsed, damaged areas,
looseness, improper installation, or leaking, especially between the mass
air flow (MAF) sensor and the throttle body. |
| • | Inspect for air leaks at throttle body mounting area, mass air
flow (MAF) sensor and intake manifold sealing surfaces. |
| • | Inspect the wiring harness for poor connections, pinches, cuts,
or other damage. |
| • | Inspect for loose, damaged, or missing sensors and/or components. |
Use the following tables when diagnosing a symptom complaint:
