Important Preliminary Checks Before Starting
Before using the Symptom tables perform the following preliminary checks:
| • | The PCM and the malfunction indicator lamp (MIL) are operating
correctly. |
| • | There are no DTCs 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, refer to
Intermittent Conditions
.
Visual/Physical Inspection
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 |
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 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. Refer to
Emission Hose Routing Diagram
. |
| • | Inspect the air intake ducts for being collapsed, damaged areas,
looseness, improper installation, or leaking, especially between the 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/components. |
| • | Inspect the aftermarket/after factory add-ons and accessories
for correct installation. These accessories may lead to an emission related
failure while in use, but do not fail when the accessories are not used. Following
the manufacturers instructions do not gaurantee the accessories will not interrupt
the vehicles normal operation as manufactured. |
Use the following tables when diagnosing a symptom complaint:
