Important Preliminary Inspections Before Starting
Perform the
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. |
| • | Ensure no DTCs are stored. |
| • | Verify the customer concern. |
| • | Perform the Visual/Physical Check in this section. |
Visual/Physical Check
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:
| • | 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:
