Important Preliminary Checks
Checks
| Action
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Before Using This Section
| Before
using this section, you should have performed the Powertrain On-Board Diagnostic
System Check and determined that:
- The VCM (Vehicle Control Module) and MIL (Malfunction Indicator
Lamp) are operating correctly.
- There are no Diagnostic Trouble Codes (DTCs) stored, or a DTC
exists but without a MIL.
Several of the following symptom procedures call for a careful visual
and physical check. The visual and physical checks are very important. The
checks can lead to correcting a problem without further checks which may
save valuable time.
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Visual and Physical Checks
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| • | Check the VCM grounds for being clean, tight and in their proper
location. Refer to VCM Description. |
| • | Check the vacuum hoses for splits, kinks and proper connections,
as shown on the Vehicle Emission Control Information label. |
| • | Check thoroughly for any type of leak or restriction. |
| • | Check for air leaks at all the mounting areas of the intake manifold
sealing surfaces. |
| • | Check the ignition wires for the following conditions: |
| • | Check the wiring for the following items: |
| • | The following symptom tables contain groups of possible causes
for each symptom and cover several engines. The following symptom tables cover
several engines.The order of these procedures is not important. If the scan
tool readings do not indicate the problems, then proceed in a logical order,
easiest to check or most likely to cause first. In order to determine if
a specific vehicle is using a particular system or component, refer to the
Control Module Wiring Diagrams for an application. |
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Symptom
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- Verify the customer complaint.
- Locate the correct symptom table.
- Check the items indicated under that symptom.
Use the following tables when diagnosing a symptom complaint.
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