Knock Sensor

Connect the knock sensor up to an oscilloscope.

Draw the waveform on the graph below

Explain why we are reading a voltage from this sensor when we are not supplying a voltage to it.

The knock sensor has a pizo crystal inside it. When knocking occurs in the combustion chamber, it sensors the crystal to vibrate producing voltage.

Oxygen Sensor

ANY o2 sensor that will generate 0.9 volts or more when heated, show 0.1 volts or less within one second of flame removal, AND pass the two minute heat test is good regardless of age. When replacing, don't miss the opportunity to use the test above on the replacement.

Speed or Position Sensors

Inductive sensor

Magnetic reluctor sensor

Instructions

1. Obtain an electronic inductive distributor.
2. Visually inspect condition.
3. Test ignition primary amplifying module for serviceability.
4. Test pickup (trigger) coil for serviceability.

		Specifications Toyota	Actual ohms	Serviceable?
G Pickup Coil (G+ - G-)	Cold	185-275	243 ohms
NE Pickup Coil (NE+ - NE-)	Cold	370-550	486 ohms

Note: cold is from -10 degrees  50 Celsius

Check Air Gap: Using a feeler gauge, measure the air gap between the pickup coil projection and the reluctor tip.

Adjusting Reluctor Air  Gap on Magnetic Distributor

Method

Using brass feeler gauges only, proceed to adjust the reluctor / pickup coil air gap given specifications. 

Adjusting the reluctor air gap

	Specifications	Actual	Serviceable?
G Pickup Coil	Air Gap: 0.2 – 0.4 mm (0.008 – 0.016 in.)	0.008 – 0.203 mm	Yes
NE Pickup Coil	Air Gap: 0.2 – 0.4 mm (0.008 – 0.016 in.)	0.008 – 0.203 mm	Yes

Signal Circuit: Refer to the signal waveform and compare.

Spin the distributor either by hand or in a synchograph machine.

Capture the signal waveform on a digital oscilloscope and record below (with time and voltages). Show the peak to peak and peak voltage as well as wave time.

Describe the waveform using arrows and A, B, C etc. What is happening at different points?

In the arrows A it is 5 v and arrow B 3.35 second lean. It runs rich when the fuel injector spray and get lean when the fuel injectors do not spray.

 A - Positive 5 v

 B - Zero 0 v

 C - Negative 5 v

and trigger is 5 v

Hall -Effect Sensors

Wire up the distributor as shown in the wiring diagram. Connect an oscilloscope then spin the distributor and observe the waveform.

 Hall- effect Distributor

Start at the point where the voltage output changes, then turn the distributor clockwise until the voltage changes again, note the degrees turned and the voltage obtained. Then repeat until a full revolution is completed.

Degrees turned	Voltage
60	2.39
120	2.59
180	2.92
240	3.12
300	3.18
360	3.20

Draw the waveform

Describe the waveform using arrows and label using A, B, C etc. What is happening at different points?

Show the peak to peak and peak voltage as well as wave time.

The distributor is broken not working properly. We connected it with oscilloscope but did not retrieve a good result. With CH, 5.00v ms10.0ms ch 200mv but the wave is not good enough. Refer to the above image.

Optical Distributor

Wire up the distributor as shown in the wiring diagram. Connect an oscilloscope then spin the distributor and observe the waveform.

Red -12v

Black -Earth

Blue -Signal out

Position	Voltage
90	11.55
180	0.37
270	11.55
360	0.37

Draw the waveform

Show the peak to peak and peak voltage verses time.

Describe the waveform using arrows and A, B, C etc. What is happening at different points?

Arrow A is a positive 5 volts

Arrow B - At this point we get high voltage where the steal chopper plate in place between Hall integrated circuit and magnet and this is the dwell angle too.

Arrow C - This is where we get zero voltage and the gap is the smallest between the sensor and middle core and  also we call this the well time.
Arrow D - 1.1 volts signal on
Arrow E - Zero volts signal off
Arrow F - Firing period
Arrow G - Time (ms) which is one signal
Arrow H - Peak voltage

Explain the difference between Hall Effect, optical and inductive signals

Hall effect and induction non contact technology based on the principle that for given current flow a proportional magnetic field is produced around the current carrying conductor. Both technology measure this magnetic field but with different sensing method.The Hall effect and induction use different techniques to measure the magnetic field around a current carrying conduction. The Hall effect sensor is best suited to DC current and the inductor sensor to AC current.

In each of the speed sensors above, how does the degrees turned relate to the degrees of crank shaft rotation?

The Hall effect is a chip of semi conductor material carrying a signal current. It is exposed to a magnetic field a small voltage called to Hallvoltages is generated between the chip edge at 90 degrees to the path taken by the signal current optical is 360 degrees.

Injector testing

Note:

Injectors from systems that use dropping resistors int he power feed to the injector can be identified from those that do not by their resistance value.

Common values:

With resistor                                                             1.5 - 3.0 ohms

(Or with current control built into the E.C.U)

Without resistor:                                                        14.0 - 17.0 ohms

All four injectors spray evenly, the spray patterns are cone shape, No leakage, the flow rate is the same for all four injectors and no dripping when the machine turned off.

Injector electrical tests

Injector number.                          1                          2                           3                             4
Manufacturers Specification ohms	1.5-3.0 ohms	14.0-17.0 ohms	1.5-3.0 ohms	14.0-17.0 ohms
Wind resistance ohms	3 ohms	13.7	13.8	13.7
Earth leakage test

Practical task sheet


Checking injectors Off a vehicle

Take are there is no pressure in the fuel rail and not damage the fuel injector.

Checking injectors for audible "click"

Injector number	1	2	3	4
Injector operation Audible.	Yes	Yes	Yes	Yes

Test bench cleaning 

Cleaning injectors off a vehicle

Take care there is no pressure in the fuel rail and not damage the fuel injectors.

Now wire up your injectors to a power supply and listen to see if they click.

Injector  leakage. None  Drips per minute. 30 ml per 10 seconds.

Injector flow rate 165 ml cc.per minute flow rate at 0.016 Hz.

Test results

Injector Number Condition (Circle one) Spray pattern Flow rate Injector Leakage (dribble)	1		2		3		4
	√	No	√	No	√	No	√	No
	√		√		√		√
	√		√		√		√
	√		√		√		√

Analysing your results

Describe the condition of all the injectors that you tested?

All four injectors spray evenly. The spray pattern are cone shape no leakage. The flow rate is the same for all four injectors and no dripping when the machine is turned off.


Testing ignition Coils

To test the ignition resistance of the primary and secondary windings, follow the diagrams below.

Testing ignition coils


Method


1 Obtain two different ignition coil configurations.
2 List all coil part numbers, voltage, internal resistance specifications where shown.

Coil Specification
Coil #1 Cic 31 Coil #2 No Cic 31
Coil #1 Voltage 12 volts Coil #2 Voltage 12 volts
Coil #1 Primary 0.3-0.5 ohms Coil #2 Primary 3.00-4.00 ohms
Coil #1 Secondary 9.35 k ohms Coil #2 Secondary 7-8 k ohms


Coil Test Results

Coil	#1	Primary	0.6 ohms
Coil	#1	Secondary	12.62 ohms
Coil	#1	Earth leakage test	0.3 ohms
Coil	#2	Primary	3.0 ohms
Coil	#2	Secondary	9.35 k ohms
Coil	#2	Earth leakage test	3.0 ohms

Wasted Spark Coil Pack

Coil	#1	Secondary	6.95 k ohms
Coil	#2	Secondary	6.90 k ohms
Coil	#3	Secondary	6.93 k ohms
Coil	#1	Primary	6.95 k ohms
Coil	#2	Primary	6.90 ohms
Coil	#3	Primary	5.93 ohms

Testing Ballast resistors

1 Obtain 2 ballast resistors with different part numbers

2 List part numbers and resistance specifications (s)

3 Measure the resistance of the resistors

Specifications

Ballast resistor 1NO BR3 Ballast resistor 2 NO BR1

Ballast resistor NO 1 ohms 1.5 -1.7ohms spec Ballast resistor NO 2 ohm spec 0.9-1.1 ohms

Measured Resistance Values

Ballast resistor No1 measured ohms 1.9 ohms                               Serviceable

Ballast resistor No 2 measured ohms 1.7ohms                               Serviceable

Measuring Current Draw and Voltage Drop

Standard Single tower coil

1. Wire up a ballast resistor in series with your coil primary winding values as shown in the following diagram.

2. Connect an ammeter in series and note the current draw.

3. Measure and note the voltage drop across the ballast resistor.

4. Measure and note the voltage drop across the coil primary.

Current draw 4.56 A

Coil calculated Voltage Drop V=IR=4.56x0.6=2.73v

Coil measured Voltage Drop 2.25v

Ballast resistor calculated voltage drop V=IR=4.56x1.9=8.66v

Ballast resistor measured voltage drop 8.22v

Oscilloscope Patterns to Capture

The following five sensors are used for WS3A:
   MAP (Analogue voltage)
   MAF (analogue)
   TPS (linear type)
   ECT
   IAT

Explain the operation of the sensor or device using the Graph:

(Use arrows at different points, and describe what happens there)

A and 

B = Idle

B = Acceleration - high voltage and low vacuum.

C = Accelerating

D = Keep open the throttle for the intake air

E = 

Deceleration

Explain in detail an electrical fault that would make this unit operate incorrectly?

If the base timing is set incorrectly there will be no EST signal engine will not operate.

Explain why this condition would cause this unit to malfunction/ Use mathematical equations to back up your explanation?

Diagnostic trouble codes that effect vehicle emissions will cause the malfunction. Before diagnostic the MAP sensor checks the hose feeding the sensor and leaks. Sensor circuit can cause problems with the hall effect sensor.

Explain how this condition would affect the operation of the vehicle?

The sensors ground circuit must be in good condition. A poor ground connection will have the same effect on the sensor operation.

Signal Name: MAP Digital

(Use arrows at different points, and describe what happens there)

B = Sudden deceleration decrease voltage

C = Slow motion or slow decrease of voltage as decelerating slowly.

D = Quick acceleration and quicker response in the voltage increase.

E = Normal or Con-slant Idle and slight change in voltage.

Explain in detail an electrical fault that would make this unit operate incorrectly?

Poor connection or dirt will make this unit to operate incorrectly.

Explain why this condition would cause this unit to malfunction/ Use mathematical equation to backup your explanation?

This malfunction can take the form of a damaged or sluggish sensor or a broken cause the sensor to indicate a false lean condition which in turn will cause.

Explain how this condition would affect the operation of the vehicle?

When condition change and the vehicle is crushing a long under light lead engines will affect the operation of the engine management system.

Signal Name: ECT

Volt/division/range: 1 v

Time/division/range: 20 s

(Use arrows at different points, and describe what happens there)

A = 2.2 volts  cold engine at the start

B = Continuing to drop voltage

C = 1.9v after 100 seconds

Explain in detail a condition would make this unit operate incorrectly?

Higher resistance will cause higher coltage drop which it gets from  the ECU (5v) will cause the wrong return voltage signal to the ECU.

Explain why this condition would cause this unit to malfunction/ Use mathematical equations to back up your explanation?

As the temperate increases of the coolant the resistance decreases and the return voltage signal decreases too. Ref v = 5v

ie. If the variable resistance R2 is 2500 ohms and R1 in the PCM is 1000 ohms then the total current I = V/R = 5/3500 = 0.0014A

Therefore the voltage drop V0 = IR = 0.0014 x 2500 = 3.5v in variable resistor and the return voltage is 3-3.5 = 1.5v.

If the resistance in sensor ground increase for example 1000 ohms so the voltage drop at the resistor will be V02 = IR

It = V/Rt = 5/4500 = 0.001A

and Vd2 = IR = 0.001 x 100 = 1v

Vd1 = IR = 0.001 x 2500 = 2.5v, the voltage drop change in variable resistor from 3.5v to 2.5v and the ECU will determine the PWM according to this wrong voltage of 2.5v.

Explain how this condition would affect the operation of the vehicle?

The graph marked with m, is a straight high, there is no change in voltage drop, and the engine is in open loop and running rich because the ECU fail to go into close loop once the engine is warm as it gets strong signal from the ECT because of the resistance in the component.

Signal Name: IAT

Volt/division/range: 2v

Time/division/range: 20s

(Use arrows at different points, and describe what happens there)

A = 0v

B = When the engine was cold voltage was about 0.7v

C = When warmed up after 200 seconds the voltage was almost 0v.

D = Voltage continue dropping.

Explain in detail a condition would make this unit operate incorrectly?

If the IAT resistance is high when the engine heated up it will have the return voltage. Signal wrong to the ECU.

ie. The resistance drops as the temperature increases.

Explain why this condition would cause this unit to malfunction/ Use mathematical equations to backup your explanation?

Since the ECU sends a reference voltage of 5v and gets the return respect to the voltage drop and then determines the condition of the engine.

ie. If the variable resistor is R2 = 2500 ohms, Ref v = 5v, R1 = 1000 then the total current I = V/R = 5/2500+1000 = 0.0014A. 

So, the voltage drop will be V = IR = 3.5v then the signal voltage is 5-3.5 = 1.5v therefore the ECU will determine the amount of fuel needed for the condition of the engine, if the resistance increases in the sensor ground side, then 3.5v drop will decrease as well, so this will affect the function of the sensor and ECU will receive wrong signal and make wrong adjustments to PWM.

Explain how the condition will affect the operation of the vehicle?

There is no change in voltage as the engine heated up after 200 seconds and the ECU still reads this high voltage as cold engine condition to it sprays more fuel and consuming more fuel.

Signal Name: 02 Sensor

Volt/division/range: 0.5v

Time/division/range: 15s

(Use arrows at different points, and describe what happens there)

B = When the engine runs lean

A = When the engine is lean

D = Peak - maximum riches before gets lean

C = Peak - maximum lean before the engine starts to get rich 

WS3 General Lab Scope

Signal Name: TPS Linear Type

Volts/division/range: 2v

Time/division/range: 5s

(Use arrows at different points, and describe what happens there)


B = Represents at the Idle voltage about 0.2v
C = Where the TPS is opening and indicates in voltage
D = Where throttle body is wide open and this is the maximum voltage
E = Where the throttle body is closing and reduces voltage
F = Where the throttle body is closed but does not close 100% and we get about 0.2v

Signal Name: RPM (CMP) Sensor

Volt/division/range: 2v

Time/division/range: 50ms

(Use arrows at different points, and describe what happens there)


This is analogue waveform representing the crank position and channel representing cam sensor per each revolution of crank. The position is going 4 times up and down as shown in the graph. 
A magnetic field is creating
A magnetic field is created
Sudden collapsing of magnetic field and pulse is generated
Magnetic field is collapsed and it is in its lowest value (Back EMF).

WS6 Oxygen Sensors on Vehicle

1.1 Locate an oxygen sensor on your vehicle. Describe where it is located:

Above inlet maniforld

1.2 How many wires for this oxygen sensor?

4 wires

1.3 Record the colors for each of the wires at the sensor side of the connector (not the ECU side of the connector): Then list the use of the wires. Usually a black or blue wire will be the O2 sensor signal, Grey may be the sensor ground. Heater power and ground are often white. But there may be other colors. You may have to consult a wiring diagram.

Colour      Use or Purpose

Black         Signal

Grey          Sensor ground

White        Heater supply

White        Heater ground

1.4 What type of Oxygen Sensor is this?

Titania switching sensor

3.1 Freeze your pattern and draw or photograph it onto the graph below?

3.2 How high does the voltage go?

1v

3.3 How low does the voltage go?

0.2v

3.4 What is the average voltage? (Some oscilloscopes have functions that will calculate the average for you. If not, just guess.)

0.5v

4.1 Freeze your pattern and draw or photograph it onto the graph below?

4.2 How high does the voltage go?

0.98v

4.3 

How low does the voltage go?

0.2v

4.4What is the average voltage? (Some oscilloscopes have functions that will calculate the average for you. If not, just guess.)

0.4v

4.5 How many "Cross Counts" does the signal have in 10 seconds? (One cross count is when it goes from high to low, or from low to high.) List here: 14

4.6 If the signal is not cycling normally, describe what the signal does?

The signal may have Negative pattern on the graph (-0.2v)

5.1 Freeze your pattern as it goes rich and draw or photograph it onto the graph below?

5.2 How high does the Oxygen sensor voltage go?

1.1v

5.3 If this signal is not going high normally, describe what the signal does?

It will have very low voltage and it will be lower than 1.1v

6.1 Freeze your pattern as it goes rich and draw or photograph it onto the graph below?

6.1 How low does the Oxygen sensor voltage go?

0.00v

6.2 If this signal is not going low normally, describe what the signal does?

The signal will be above 0v

7.0 Measure the Response Time of the sensor

7.1 Freeze your pattern as it goes suddenly rich from a lean condition and draw it into the graph below: Normally you want the voltage to go from below 0.2v to above 0.8v. In less than 100 ms. 

7.2 Measure how long the sensor took to go from lean to rich. Use the cursors on the scope if necessary. Record how long the sensor took here?

40 ms

8.0 Discuss how a normal Zirconium oxygen sensor works: draw a picture below to help show how it works?

Zirconium oxygen sensor has two electrodes provide an output voltage corresponding to the quality of oxygen in the exhaust in relation to the atmosphere and output of 0.2v represents a lean mixture and an output of 0.8v represents a rich mixture.

9.0 Discuss how good or bad this Oxygen Sensor is. What about it functions well or is faulty? Use detail and specific voltages in your discussion. Can it accurately tell the ECU how rich or lean the exhaust is?

This sensor eliminates the rich-lean cycling allowing the control unit to adjust the fuel delivering and ignition timing of the engine much more rapidly but less sensitive to either rich or lean. 0.2v represents lean and 0.8v represents rich mixture. 

WS8 Primary & Secondary Ignition Patterns

1.0 Primary Voltage Patterns

   1.1 Set up a lab scope or ignition oscilloscope to view the primary ignition pattern (in parade or display mode) on your lab scope, with the engine warmed up and idling.

   1.2 Record the average Firing Voltage 

   1.3 Record the average Burn Voltage for each cylinder in the chart below.

   1.4 Record the average Burn Time in milliseconds for each cylinder in the chart below.

   1.5 Record the average Dwell Time  for each of the cylinders in the chart below. What unit of measurement are you using to measure the dwell time?

   1.6 Are all these primary ignition voltage readings normal? Yes

Yes, these voltage readings are all normal. The firing voltage, burning voltage and dwell time are all constant for all 4 cylinders, if there were any differences in voltage either Firing voltage, Burning voltage or burning time for any cylinder that would be abnormal and the engine would not run smoothly. Therefore the engine for this reading was running smoothly and no hesitation or misfiring deleted.

Cyl 1	Cyl 2	Cyl 3	Cyl 4	Cyl 5	Cyl 6	Primary Ignition
300v	300v	300v	300v			Firing Voltage
40v	40v	40v	40v			Burn Voltage
1.4ms	1.4ms	1.4ms	1.4ms			Burn Time
4.6ms	4.6ms	4.6ms	4.6ms			Dwell Time

1.7 Draw the primary ignition lab scope parade or display pattern from your scope into the box below. Do it carefully and show the detail you need to see for diagnosis. Record voltage and time scales.

1.8 Discuss what the primary display or parade pattern emphasizes for diagnosis. What can it help see?

Point A is the dwell period that is when the coil is grounded. Point B is  the current limiting and this will prevent heat bring generated in the coil primary. Point C is Firing voltage when spark occurs. Point D is the burning voltage shows. Point E is the back MF and return to 0.

2.0 Secondary Voltage Patterns

2.2 Record the average Firing Voltage

Are all these secondary ignition voltage readings normal? Yes

As from data we collected in the chart below shows all four cylinder have constant voltage and burning time at snap acceleration. The secondary coil spike tells us the ignition system is firing (high voltage) and the burning time about to start, we see it is very face with the full voltage spike take about 0.6 ms (milliseconds) and burn time at about 1ms which is normal for the secondary pattern.

Cyl 1	Cyl 2	Cyl 3	Cyl 4	Cyl 5	Cyl 6	Secondary Ignition
13kv	13kv	13kv	13kv			Firing Voltage (KV)
1.6ms	1.6ms	1.6ms	1.6ms			Burn Time (ms)
Yes	Yes	Yes	Yes			Snap Acceleration

2.7 Draw or photograph the Secondary Ignition lab scope pattern while idling from your scope into the box below.

2.8 If you can safely do this, (with the engine stopped), gently disconnect one spark plug wire, and short to the engine with a jumper wire. Which cylinder number did you short? One

2.9 Start the engine and let it idle (for only a short time.) Record the new Firing Voltage and Burn Time for all the cylinders in the chart below.

Cyl 1	Cyl 2	Cyl 3	Cyl 4	Cyl 5	Cyl 6	Secondary Ignition (one cylinder grounded)
6kv	3kv	6kv	7kv			Firing Voltage (KV)
3ms	3ms	3ms	3ms			Burn Time (ms)

2.10 Draw or photograph the shorted Secondary Ignition waveform you see now on your scope .

2.11 Discuss what is happening in the shorted ignition pattern and how the ignition pattern tells you what it is happening in the ignition system?

The graph shows us when the coil is grounded the primary magnetic field collapsed and into the secondary windings. This is the secondary ignition spike which is about 3kv in one milliseconds, burning time progressed to about 2ms.

2.12 Remove the ground wire and attach the spark plug wire back on the engine so it is normal again. Run the engine a bit to clear the spark plug.

2.13 Stop the engine and attach a spark tester to another spark plug wire. Start the engine and let it idle (for only a short time). Record the new Firing Voltage and Burn Time for all the cylinders in the chart below.

Cyl 1	Cyl 2	Cyl 3	Cyl 4	Cyl 5	Cyl 6	Secondary Ignition (Spark tester on one cylinder)
6kv	14kv	7kv	6kv			Firing Voltage (KV)
3ms	1.5ms	3ms	3ms			Burn Time (ms)

2.14 Draw or photograph the spark tester Secondary Ignition waveform you see now on your scope. Show the detail that is necessary for accurate diagnosis. Include time and voltages.

2.16 Discuss what happens to the ignition waveform when the spark tester is attached to the spark plug wire. What does it tell you about the ignition system.?

The three cylinder with the normal spark plugs shown no abnormality, all three had almost the same pattern spikes, burning time and voltages except cylinder #2. The tester has much higher firing voltage about 1500v, the burning time has reduced dramatically, this indicates as we have applied the string theory in this exercise. The larger the gap, higher firing voltage and shorter is the burning time.

WS5 Scan Tool Diagnostics

Type of information (PID = Parameter Identification)	Letters to describe it E.G. TPS	Value of data	Units for data E.g. volts
E ngine Load (how much air comes in)		45.5	%
Throttle RPM		931	RPM
Throttle Angle			%
Engine coolant temperature	T	93	Celsius
Intake air temperature		43	Celsius
Fuel injection opening pulse		45.5	ms
Transmission select position		P	P
Vehicle Speed		O	Kph
Oxygen sensor(s)		0.835	V
Fuel Trim		2.3	%
Idle control		0.88	V
Power steering condition		0.02	V
Air conditioning condition		3.89	V
Exhaust Gas Recirculation (EGR)		No	N/a
Fuel Evap or Purge condition		0	%
Malfunction Indicator Light (MIL)		Off
Barometric Pressure		79	Hz pulsing

4 Record New Codes

   4.1 Look up the codes no in the scan tool

   4.2 Record the codes in the chart below. Also record what system is affected, what condition is described.

Code number	System affected	Condition described
P0113	IAT	High input (Voltage)
P0108	MAP	High input
P0122	TPS	Low input
P01504	IAC ckt	Malfunction

5 Find What Data Has Changed

   5.1 Look through the scan tool data to see what PIDs (Parameter Identification of system voltages) have changed. Which readings don't make sense or don't read what you would expect. Concentrate on the PIDs related to the codes.

   5.2 Record the PIDs that have changed below:

Type of information (PID = Parameter Identification)	Letters to describe it	Value of Data	Units for data
IAT	IAT	15	Celsius
TPS	TPS	0.00	%
MAP	MAP	107	Kpa
Idle Air Control	IAC	1.11	Yes

6 Visual Inspection to find fault

   6.1 Do a visual inspection under the hood to find where the problem is.

   6.2 Describe problem you found:

         Disconnect all the above wires of the sensors

7 Repair Fault

   7.1 Plug back in the connector, or repair problem found

   7.2 Describe what you did:

         Put them all back in or plug them in

8 Recheck Data PIDs
   8.1 Recheck the data with the scan tool
   8.2 Record the voltages for the PIDs related to the problem, to confirm they are back to normal

Type of information (PID = Parameter Identification)	Letters to describe it	Value of data	Units for data
IAT	IAT	47	Celsius
TPS	TPS	18.8	%
MAP	MAP	102	Kpa
IAC	IAC	0.94	√

9 Clear Codes

Describe what you did to clear codes:

We have to turn the engine off and put the disconnect plugs in and start the engine and it will clear all the codes. For this exercise the key should be on and engine off and erase the code on the scan tool.

10 Recheck for codes and record codes in system now:

On rechecked there is no codes on the scan tool.

11 Discuss the importance live data when fault finding

We have to check the data when engine is running smoothly and is in good condition so we can compare their data with a faulty component's data.

12 Explain the need for parameters when checking live data

This are very important to check the parameter in different condition the engine is for instance the engine load, how much air is coming in.

13 Discuss how a scan tool can aid you when fault finding?

Scan tool is important device for finding a fault, it gives code number and type of information PID (Name of the sensor)