Important Preliminary Checks
Checks
| Action
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Before Using This Section
| Before using this section, perform the On-Board Diagnostic
System Check and determined that:
- The ECM and Malfunction Indicator Lamp (MIL) are operating correctly.
- There are no Diagnostic Trouble Codes (DTCs) stored.
- There is a diagnostic code but no MIL.
- Several of the following symptom procedures call for a careful
visual/physical check. The importance of visual/physical checks cannot be
over stressed. The visual/physical checks can lead to correcting a problem
without further checks and can save valuable time.
|
Before Starting
|
| • | Check the ECM grounds for being clean, tight, and in their proper
locations. |
| • | Check the vacuum hoses for splits, kinks, and proper connections,
as shown on Vehicle Emission Control Information label. Check thoroughly for
any type of leak or restriction. |
| • | Check for air leaks at all mounting areas of the intake manifold
sealing surfaces. |
| • | Check the ignition wires for the following: |
| • | Check the wiring for proper connections, pinches, and cuts. Refer
to Wiring Repairs
in Body and Accessories. |
| • | The following symptom tables contain groups of possible causes
for each symptom. You do not have to perform these procedures in consecutive
order. If the scan tool readings do not indicate the problems, then proceed
in a logical order, easiest to check or the most likely cause first. In
order to determine if a specific vehicle uses a particular system or component,
refer to the ECM Wiring Diagrams
for application. |
|
Symptom
|
- Verify the customer complaint.
- Locate the correct symptom in the table of contents.
- Check the items indicated under that symptom.
- Use the following tables when diagnosing a symptom complaint:
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