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This set of eight lesson plans is designed to be taught sequentially, beginning with closed loop operation and carrying on through oxygen sensors and methods of testing and diagnosing.  It includes five lecture-based lesson plans and three lab-based lesson plans.  It designed to correlate to NATEF task lists relating to engine performance, computer-control, feedback systems, and oxygen sensors.  Worksheets filled out in lab should directly correlate to appropriate NATEF task list.

 

EVOC Lesson Plan 1

 

Teachers organize curriculum to facilitate students' understanding of the central themes, concepts, and skills in the subject area. Teachers interrelate ideas and information within and across curricular areas to extend students' understanding.

(From teaching standards)

 

Subject: Automotive Engine Performance

 

Instructor: Phil Fournier                   Time required: 2 hours

 

Student Performance Objective:  By the end of this lesson the student will be able to describe in writing the concept of closed loop fuel control, using the three point triangle illustration.

 

How will the students be evaluated?  Students will be evaluated with an essay type quiz that requires students to draw the diagram describing closed loop fuel control and to describe in short essay form the concepts and the rationale behind the diagram.

 

Anticipatory set:  Introductory question: What is the single most important reason we have computer control on cars today?

 

Instructional Components:

Lecture using PowerPoint

  • Emission and catalytic converters
  • Stoicometry and Lambda
  • Three components of triangle
    • Computer
    • AF or Oxygen Sensor
    • Fuel control device (carb or fuel injection)
  • Illustrate using triangle with three components

 

Check for understanding:

Ask questions then pick students by name to answer questions; why do we need computer control?  What are the three components of closed loop fuel control?  What is the meaning of Lambda 1?  What is the concept behind a stoic fuel ratio?

 

Closure:  Go around the loop of the “closed loop” again and describe the consequences of drifting to either side of Lambda 1.  Re-emphasize the importance of fuel control and its emissions consequences.

Materials needed:  Computer, PowerPoint software, LCD projector, white board and dry erase markers, eraser, student textbook.

 

EVOC Lesson Plan 2

 

Teachers plan instruction that draws on and values students' backgrounds, prior knowledge, and interests. (From teaching standards).

 

 

Subject: Automotive Engine Performance

 

Instructor: Phil Fournier                   Time required: 2 hours

 

Student Performance Objective:  At the end of this lesson the student should be able to describe in writing the process by which a zirconium single wire oxygen sensor generates a voltage.

 

How will the students be evaluated?  Student will be evaluated with a five question, fill-in-the-blank quiz.

 

Anticipatory Set:  So, you assumed an oxygen sensor sensed oxygen, right?  Well, they do but….

 

Instructional components:

  • Visual aid: Show the components of the cut-away oxygen sensor
  • Lecture: Using PowerPoint animated presentation, cover the operation of the zirconium oxygen sensor.
    • 600 degree temperature needed
    • Voltage output zero to one volts
    • Catalytic action
    • Oxygen ions
    • HC, CO, and H2 demands for O2 in a rich condition
    • Absence of demand in a lean condition

 

Check for understanding:

Ask the question of what would happen if the oxygen sensor were surrounded by an inert gas with no oxygen.  Would the sensor produce a voltage?  Why or why not?  Ask the question and then pick a student to answer.

 

Closure: Re-emphasize the principle of zero to one volts, high voltage rich, low voltage lean.

 

Materials needed: Computer, PowerPoint software, LCD projector, white board and dry erase markers, eraser, student textbook.

 

EVOC Lesson Plan 3

 

Teachers use instructional activities that promote learning goals and connect with student experiences and interests. (From teaching standards)

 

Subject: Automotive Engine Performance

 

Instructor: Phil Fournier                   Time required:  3 hours

 

Student Performance Objective:  At the end of this lesson the student should be able to reproduce a high and low voltage on a voltmeter tracking oxygen sensor voltage.

 

How will the students be evaluated?  Student will be by filling out the oxygen sensor testing exercise worksheet found in the workbook.

 

Anticipatory Set:  So, how can we prove that a rich condition will create a high voltage and a lean condition will create a low voltage?

 

Instructional components:

·        Students will group together in groups of three and choose a leader

·        Group leader will check out a voltmeter from the tool room

  • Voltmeter: students will set the voltmeter to read 0-3 volts
  • Lab exercise: Tap into the oxygen sensor circuit
    • Start engine, watch warm-up conditions, record results
    • Watch for switching signaling closed loop operation
    • Simulate a rich signal by adding fuel-observe and record
    • Simulate a lean condition by creating an air leak-observe and record
  • Answer questions on worksheet

 

Check for understanding:

Regroup students in classroom.  Ask questions regarding observations.

 

Closure: Re-emphasize the principle of zero to one volts, high voltage rich, low voltage lean.

 

Materials needed: Voltmeter, piercing probe, worksheet, pencils, computer controlled vehicles equipped with zirconium o2 sensors.

 

EVOC Lesson Plan 4

 

Teachers sequence curriculum and design long-term and short-range plans that incorporate subject matter knowledge.  (From teaching standards)

 

Subject: Automotive Engine Performance

 

Instructor: Phil Fournier                   Time required: 2 hours

 

Student Performance Objective:  At the end of this lesson the student should be able to describe in writing the process by which three wire zirconium oxygen sensor heater works.

 

How will the students be evaluated?  Student will be evaluated with a five question, fill-in-the-blank quiz.

 

Anticipatory Set:  So, how are we going to assure that the requisite 600 degree temperature is reached by the sensor?

 

Instructional components:

  • Visual aid: Show the components of the cut-away oxygen sensor
  • Lecture: Using PowerPoint animated presentation, cover the operation of the zirconium oxygen sensor heater circuit.
    • 600 degree temperature needed, heater will get us there much quicker
    • Closed loop operation as very low coolant temperature
    • Heater circuits can be computer or non-computer controlled
    • O2 sensor heater relay
    • Computer ground side duty cycle control
    • Heater circuit current draw
    • Consequences of heater malfunction

 

Check for understanding:

Ask the question of what would happen if the oxygen heater circuit was shorted to ground?  How does the heater help lower emissions?

 

Closure: Re-emphasize the principle of quick closed loop operation allowed by heated sensors.

 

Materials needed: Computer, PowerPoint software, LCD projector, white board and dry erase markers, eraser, student textbook.

 

 

EVOC Lesson Plan 5

 

Teachers use instructional activities that promote learning goals and connect with student experiences and interests. (From teaching standards)

 

Subject: Automotive Engine Performance

 

Instructor: Phil Fournier                   Time required: 3 hours

 

Student Performance Objective:  At the end of this lesson the student should be able to monitor the operation of an oxygen sensor heater and trace its circuit in a wiring diagram.

 

How will the students be evaluated?  Student will be evaluated by filling in a worksheet and a five question, fill-in-the-blank quiz.

 

Anticipatory Set:  Suppose you have a code for an oxygen sensor heater circuit.  What are we going to do next?  You better not answer “replace the oxygen sensor”!

 

Instructional components:

  • Visual aid: Access the heater circuit wiring diagram for one of the school cars to be used in the lab exercise.
  • Trace the heater circuit for the students on the LCD projection
  • Lab: Students in groups of three will choose a leader. Leader will check out a voltmeter and current probe from the tool room while other two print out the wiring diagram for their vehicle.
    • Students will trace the heater circuit using colored pencils to identify the power and ground circuits and circle any relays or fuses
    • Students will locate fuse or relay on their car using the component locater
    • KOEO: Check for power to heater circuit-observe and record
    • KOER: Check for ground-observe and record
    • Using current probe, measure, observe, and record heater current draw
    • Answer questions on worksheet

 

Check for understanding:

Ask the question of what would happen if the oxygen sensor heater fuse should blow.  What voltage would they read on the ground side?

 

Closure: Re-emphasize the principle of current flow through the heater circuit.

 

Materials needed:  Current probe, voltmeter, computer with Alldata software or internet connection, printer, vehicles with heated oxygen sensors.

 

 

EVOC Lesson Plan 6

 

Teachers plan instruction that draws on and values students' backgrounds, prior knowledge, and interests. (From teaching standards).

 

 

Subject: Automotive Engine Performance

 

Instructor: Phil Fournier                   Time required: 2 hours

 

Student Performance Objective:  At the end of this lesson the student should be able to describe in writing the process by which a titanium oxygen sensor functions and compare it to a zirconium oxygen sensor.

 

How will the students be evaluated?  Student will be evaluated with a five question, fill-in-the-blank quiz.

 

Anticipatory Set:  So, an oxygen sensor produces its own voltage, right?  Well, not if we are talking titanium….

 

Instructional components:

  • Visual aid: Show the components of the cut-away titanium oxygen sensor.
  • Lecture: Using PowerPoint animated presentation, cover the operation of the titanium oxygen sensor.
    • 600 degree temperature needed, must be heated to work
    • Voltage output is variable zero to 1.2 volts or zero to 5 volts depending on application
    • Supplied with a reference voltage
    • Return voltage is backwards from a zirconium sensor
    • Voltage is high when lean, low when rich
    • Does not require ambient O2, used in application that run in mud which would clog a zirconium sensor

 

Check for understanding:

Ask the question of what a titanium O2 sensor will output with a 13:1 A/F ratio. Ask the question and then pick a student to answer.

 

Closure: Re-emphasize the contrast between zirconium and titanium oxygen sensor operation.

 

Materials needed: Computer, PowerPoint software, LCD projector, white board and dry erase markers, eraser, student textbook.

 

EVOC Lesson Plan 7

 

Teachers plan instruction that draws on and values students' backgrounds, prior knowledge, and interests. (From teaching standards).

 

Subject: Automotive Engine Performance

 

Instructor: Phil Fournier                   Time required: 2 hours

 

Student Performance Objective:  At the end of this lesson the student should be able to describe in writing reason for graphing an oxygen sensor instead of looking at its voltage only.

 

How will the students be evaluated?  Student will be evaluated with a five question, fill-in-the-blank quiz.

 

Anticipatory Set:  So, how can we look at changes in an oxygen sensor output over time rather than as a simple number on a meter?

 

Instructional components:

  • Visual aid: Show the Snap On Vantage and Fluke 870 power graphing meters.
  • Lecture: Using PowerPoint animated presentation, cover the operation of the graphing meters.
    • Voltage over time, but taken as individual readings and plotted on a graph
    • Menu driven
    • Show closed loop operation in the form of an osscilating signal
    • Better for diagnostics than a simple voltmeter
    • Can graph voltage, frequency, pressure, and more
    • Can measure sensor response time, a key component to operation

 

Check for understanding:

Ask the question of why the graphing meter presents a better picture of what is actually happening at the oxygen sensor.  Ask the question and then pick a student to answer.

 

Closure: Re-emphasize the principle of watching the changes in O2 output on a graph rather than as a number.

 

Materials needed: Computer, PowerPoint software, LCD projector, white board and dry erase markers, eraser, student textbook, Vantage meter and Fluke meter.

 

 

EVOC Lesson Plan 8

 

Teachers use instructional activities that promote learning goals and connect with student experiences and interests. (From teaching standards)

 

Subject: Automotive Engine Performance

 

Instructor: Phil Fournier                   Time required: 3 hours

 

Student Performance Objective:  At the end of this lesson the student should be able to monitor the operation of an oxygen sensor using the Vantage graphing meter or the Fluke graphing meter.

 

How will the students be evaluated?  Student will be evaluated by filling in a worksheet and a five question, fill-in-the-blank quiz.

 

Anticipatory Set:  Suppose you have a code for an oxygen sensor slow response?  What tool would be appropriate to check response time?

 

Instructional components:

  • Lab: Students in groups of three will choose a leader. Leader will check out a graphing meter and piercing probe from the tool room while other two print out the wiring diagram for their vehicle.
    • Students will trace the signal circuit using colored pencils to identify the wires on a three or four wire sensor, highlighting the signal wire
    • Students will locate the signal wire on their car using the wire color as a guide
    • Connect graphing meter to signal wire-start engine and observe warm-up and transition into closed loop-record results on worksheet
    • Observe closed loop switching.  Count frequency of switching, record results
    • Induce both rich and lean conditions-observe and record
    • Measure sensor response time using cursors-record
    • Answer questions on worksheet

 

Check for understanding:

Ask the question of why the oxygen sensor is continually switching.  Why is the response time critical to operation?  Ask question first, then pick a student to answer.

 

Closure: Re-emphasize the principle of graphing the sensor rather than looking at a number.

 

Materials needed:  Graphing meters, piercing probes, computer with Alldata software or internet connection, printer, vehicles with heated oxygen sensors, worksheet from workbook, pencils and colored pencils.