Important Preliminary Inspections Before Starting
Perform
Diagnostic System Check - Vehicle
in
Vehicle DTC Information and verify all of the following items:
| • | The powertrain control module (PCM) and malfunction indicator lamp (MIL)
are operating correctly. |
| • | There are no DTCs stored. |
| • | Verify the customer concern. |
| • | Perform the Visual/Physical Check in this section. |
Visual/Physical Inspection
Several of the symptom procedures ask for a careful visual and physical inspection.
The visual and physical inspection can lead to correcting a problem without further
inspections, and can save valuable time. First inspect the following items:
| • | 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 mass air flow (MAF) sensor
and the throttle body. |
| • | Inspect for air leaks at throttle body mounting area, MAF sensor, and
intake manifold sealing surfaces. |
| • | The ignition wires are not cracked, brittle, or carbon tracked. |
| • | Inspect the wiring harness for poor connections, pinches, cuts, or other
damage. |
| • | Inspect for loose, damaged, or missing sensors/components. |
Use the following tables when diagnosing a symptom complaint:
