Important Preliminary Checks Before Starting
Before using the Symptom tables perform the
Powertrain On Board Diagnostic (OBD) System Check
and verify
all of the following items:
| • | There are no DTCs stored. |
| • | Verify the customer's 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
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 steps:
| • | Inspect the 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 collapsing, damaged areas, looseness,
an improper installation, or leaking, especially between the MAF sensor
and the throttle body. |
| • | Inspect for air leaks at throttle body mounting area, at the mass
air flow (MAF) sensor, and at the intake manifold sealing surfaces. |
| • | Inspect the wiring harness for poor connections, pinches, cuts,
or other damage. |
| • | Inspect for loose, damaged, or missing sensors or components. |
| • | Inspect the aftermarket/after factory add-ons and accessories
for correct installation. These accessories may lead to an emission related
OBD2 failure while in use, but do not fail when the accessories are not used.
Following the manufacturer's instructions does not guarantee the accessories
will not interrupt the vehicle's normal operation as manufactured. |
Use the following tables when diagnosing a symptom complaint:
