Statement: Enrollment in this class requires that you first purchase and complete the steps for the required eBook. Next step: Please ensure you have purchased and completed the prerequisite eBook class. Once the prerequisite is marked as complete, you will be able to enroll in this class.

About this course:

CHAPTER SUMMARY:

Chapter Summary:

Fuel Trim, Base Pulse Width, Measuring Pulse Width, and Fuel Trim Operation

Using Fuel Trim as a Diagnostic Aid, Fuel Trim Cells, and Fuel Trim Cell Diagnosis

Mass Air Flow Accuracy and Volumetric Efficiency 

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OBJECTIVES:

Explain the purpose and function of fuel trim

Discuss the difference between speed density and mass air flow fuel control. 

Explain how the PCM determines the base injector pulse width.

Compare short-term and long-term fuel trim. 

Explain how fuel trim can aid in diagnosis. 

List factors that can affect the accuracy of the mass air flow sensor. 

Describe how knowing the volumetric efficiency of the engine can help diagnose engine performance concerns.