Presentation on theme: "Your Partners for the Road Ahead! Carman Scan VG NEXTECH and."— Presentation transcript:
Your Partners for the Road Ahead! Carman Scan VG NEXTECH and
What is the advantage of a Combination Data Scanner / Oscilloscope over a basic Data Scanner? A basic Data Scanner can perform the following functions: Read and Erase Fault codes Display Current Data to verify a fault exists. more than just a Scanner However, determining whether a fault is caused by a component failure, a wiring fault or a faulty ECM requires more than just a Scanner. Perform Actuation tests. The Carman Scan 1 and Carman Scan VG provide the technician with a complete solution for Diagnostics.
The use of an Oscilloscope is a necessity for pinpointing vehicle faults. During the course we will be studying the operation of the VG as well as the correct procedures required for testing a number of common components.
THE CARMAN SCAN VG TRAINING COURSE #1 OSCILLOSCOPE TRAINING
VOLTAGE TIME 0v 2v 4v 6v 8v Hz % m/s Hz = Frequency (Number of Pulses per second). % = Duty Cycle (On/Off Ratio). m/s = Time measurement.
The Lab Scope is one of the most valuable diagnostic tools available to the modern workshop today. It is commonly used to check: 1.Supply voltage 2.Voltage Drops (in power and earth circuits). 3.AC Waveforms 4.DC Waveforms (Square waves etc.) 5.Pulse Signals
+ v - v 0 v TYPICAL AC WAVEFORM AC Waveforms are generated from such devices as: Alternators (before rectification) Crank Angle Sensors TDC Sensors Vehicle Speed Sensors Transmission Pulse Generators
0 v 5 v ON 5 v 0 v ON OFF GROUND SWITCHED SIGNAL Duty Cycle 50% POSITIVELY SWITCHED SIGNAL Duty Cycle 50% TYPICAL SQUARE WAVEFORM Square Waveforms are commonly used for inputs such as: Crank Angle Sensors, Camshaft Sensors, TDC Sensors, Vehicle Speed Sensors, MAP Sensors (Ford), Air Flow Sensors or outputs such as Idle Speed Control Motors
TYPICAL PULSE WAVEFORM SOLENOID PULSE SIGNAL VOLTAGE SPIKE 12 v 0 v Typical Solenoid Pulses include: Injectors; Canister Purge Solenoids etc.
SECONDARY IGNITION OSCILLOSCOPE
Typical Secondary Ignition Patterns
Dwell Ionization (Peak)Voltage Burn Voltage Burn Time Decay Section Secondary Ignition Specifications Ionization (Peak)Voltage – 7-15 KV Burn Voltage – 1-2 KV Dwell – Depends on RPM Burn Time – 1-2 m/s Specifications – Idle, No load
Carman Scan VG Oscilloscope Operation
Selecting Secondary Ignition
Touch the “OSCILLOSCOPE” Icon. Selecting Secondary Ignition
Select the number of cylinders to be tested. Selecting Secondary Ignition
Select the type of Ignition and the approximate idle speed. Selecting Secondary Ignition type
Select the correct firing order from the list or make a new one using the numbers in “other”. Selecting Secondary Ignition firing order
Select the correct probe. E.g. “1 to1” when using a single probe, or “1 to 3” / “1 to 4” for Multi-Probes (DLI Ignition etc.) Selecting Secondary Ignition Probe Type Press “SAVE” when completed
Special Note: DLI Vehicles Conventional Ignition vehicles are normally “Negative” firing, and, therefore, the spark plugs fire from the centre electrode to the outer electrode of the plug. On DLI, Waste Spark vehicles, half of the cylinders are “Negative” firing, and therefore fire from the centre electrode to the outer electrode of the spark plug, whilst the other half of the cylinders (their mating cylinders) are “Positive”, firing from the outer electrode to the centre electrode. Please refer to the following diagram.
Electron Flow Distributor-less Ignition Operation
When connecting the VG to a DLI Vehicle, the “Positive” cylinders are connected to Channel 1 and the “Negative” cylinders, connected to Channel 2. The #1 Trigger lead is connected to Channel 3 as usual. When connecting the VG to a conventional Ignition Vehicle, the Secondary Ignition pickup lead is connected to Channel 2 of the VG and the #1 Trigger lead is connected to Channel 3 Conventional Ignition DLI Waste Spark Ignition
Determining the Positive and Negative firing cylinders If unsure which cylinders are Positive firing and which are Negative firing, simply take ONE secondary pickup lead and connect it to Channel 1 or Channel 2 of the VG. With the engine running, place the secondary pickup lead around one cylinder at a time. Any cylinders that produce an ignition pattern facing up the correct way on the scope are the correct Polarity for that channel. Please refer to the following diagrams. Any cylinders displaying an upside down pattern are incorrect polarity and therefore belong the the other Channel.
Correct Polarity for the channel selected. Note, the Ignition pattern is displayed the correct way up. Correct Polarity.
Incorrect Polarity for the channel selected. Note, the Ignition pattern is displayed upside down. Connect this Cylinder to the other channel. Incorrect Polarity.
Demonstration here of determining correct Polarity
SPLIT SCREEN (Default Screen) = Parade + Single Cylinder Note: This is a Waste Spark DIS vehicle. Mating Cylinders are: 1&4; 3&6; 5&2. Mating Cylinders are: 1&4; 3&6; 5&2.
Sets the “Voltage Scale” for the Parade and Single Cylinder Patterns. Sets the “Time Base” for the Parade Pattern only. Sets the “Trigger Level”. Adjust whenever Patterns are erratic or Cylinder #’s are erratic or missing. Allows the user to select which Single Cylinder will be displayed on the screen. Allows the screen to be changed to display the patterns as either: “Series”(Parade), “Single Cylinder”, “Trend Plot” or “3D”. Turns the “Information” display on or off. Screen Settings
Demonstration here of effects of incorrect Trigger level
Selecting a new “Single Cylinder” to be displayed To Select a new single cylinder, press “CYLINDER”, then press the cylinder #
To Select one of the other two cylinders, press “MORE”. Selecting a new “Single Cylinder” #6 Selected
Selecting other Cylinders for display. Selecting a new “Single Cylinder” #3 Selected
Demonstration here of Selecting a New Single Cylinder for Display
Changing Screen Displays
Selecting new screen displays To select new screen displays, Touch “SCREEN”
“Series” (Parade) Selected Touching “SERIES” displays the above Pattern
“Single Cylinder” Selected Touching “CYLINDER” displays the above Pattern
Selecting a New Single Cylinder
To display a different cylinder, press “Single Cylinder” Selected and then press “CYLINDER”.
Selecting a new Single Cylinder After pressing “CYLINDER”, press the “Cylinder #” required.
To select a new cylinder, Touch the cylinder # required. Selecting a new Single Cylinder
“Trend” Selected “Peak Voltage” for each cylinder is being displayed on the right Cylinder #’s Peak Voltage
“Trend” Selected “Dwell Time” for each cylinder is now being displayed on the right Dwell
“Trend” Selected “Burn Voltage” for each cylinder is now being displayed on the right Burn Voltage
“Trend” Selected “Burn Time” for each cylinder is now being displayed on the right Burn Time
3 Dimensional Raster Patterns
“3D” (3 Dimensional) Raster or ladder Pattern Selected Touching “3D” displays the above Pattern
Demonstration here of Changing Screen Displays
Display for Open Circuit HT Lead
“Split Screen” with open circuit HT lead on # 5 Cylinder Note: High Burn KV shown above. High Burn KV.
“Series Screen” with open circuit HT lead on # 5 Cylinder Also note faulty pattern on #2 Cylinder (DIS mating cylinder for #5) High Peak KV High Burn KV
“Single Cylinder” with open circuit HT lead on # 5 Cylinder Note: High Peak Volts, High Burn Volts and Short Burn Time.
“Trend Plot” with open circuit HT lead on # 5 Cylinder Note High Peak Voltage, High Burn Voltage and Low Burn Time on cylinders 5 and 2 High Peak KV Short Burn Time High Burn KV
“3D Screen” with open circuit HT lead on # 5 Cylinder Note High Peak KV, High Burn KV and Short Burn Time on Cylinders 5 and 2
High Resistance in HT Lead (High Negative Slope, with normal peak KV) Fouled Spark Plug or HT Leakage (High Negative Slope, with low peak KV) Lean Cylinder under Acceleration (High Positive Slope, under load) Other Faulty Ignition Patterns
Student Practical – Testing Secondary Ignition
VG LABSCOPE Oscilloscope Operation For the remainder of the course, all waveforms will be displayed live on your VG. Please follow setup screens as shown on the following slides.
Touch the “OSCILLOSCOPE” Icon. Selecting Lab Scope
Selecting Auto Setup Touch the“Auto Setup” Icon.
Selecting Auto Setup Select the type of signal to be tested and the channel to be used.
Selecting Auto Setup After selecting the type of signal and the channel press “SAVE” to progress to Lab Scope screen. Press “SAVE” when completed
20 m/s time-base is set for testing during “crank” conditions. If testing with the engine running reduce the time base. Testing Crankshaft Position Sensors (Hall type) – Engine idling To change the time-base, touch the side arrows or select “SET TIME”
Testing Crankshaft Position Sensors (Hall type) – Engine idling To change the voltage level, touch the up/down arrows or select “SET VOLT”
Time-base adjusted to 2 m/s (per division) for testing with the engine running. Testing Crankshaft Position Sensors (Hall type) Voltage scale set to 2v (per division) Typical Crank Angle Sensor signal at idle. Cylinder ID Signal.
Changing the Screen Settings. Changing the Screen settings: To change the screen settings touch “SCREEN”
Changing the Screen Settings. Changing the Screen settings: “Waveform only” Screen selected
Changing the Screen Settings. Changing the Screen settings: “Digital Display” Screen selected Digital readings displayed
Changing the Screen Settings. Changing the Screen settings: To change grid settings touch “GRID”
Changing the Screen Settings. To change the grid settings, select one of the above on the left.
Changing the Screen Settings. To remove the grid (as seen above), touch
Changing the Screen Settings. To display quarter grid (as seen above), touch
Selecting a second channel
Selecting a second channel for testing After selecting the second channel press “SAVE” to progress to Lab Scope screen. Press “SAVE” when completed
Testing Crankshaft and Camshaft Position Sensors (Hall type) Crankshaft Position Sensor (CKP). Camshaft Position Sensor (CMP).
5 m/s time base selected Testing Crankshaft and Camshaft Position Sensors (Hall type) Crankshaft Position Sensor (CKP). Camshaft Position Sensor (CMP).
Faulty Crank Angle Sensor Signals
Faulty Crank Angle Sensor Signal during crank. The vehicle here would not start as the hall sensor failed to switch the signal fully to ground (0v). Because of this, the ECM would not fire the Ignition. Approx 1.0v Ground = 0v Problem was caused by a faulty Crank Angle Sensor At first glance this pattern looks quite normal, however, if you study it closely you will see it’s definitely not normal.
Faulty Sensor signal captured on Carman Scan 1 Duty cycle varying. The uneven duty cycle resulted in dramatic ignition timing problems, causing backfiring, misfiring and impossible driving conditions. Problem was caused by a “brand new” faulty Crank Angle Sensor. (Should have been a constant 50% duty cycle on this vehicle)
Recording Please Note: 2. To end the recording, Press “STOP”. 3. If ‘STOP” is pressed before the full record time has elapsed, the VG will display a message to say it is “saving data, please wait” VG will display a message to say it is “saving data, please wait” 4. The length of the record time will depend on the time base selected. selected. 1. The VG is always “recording” whilst in the Lab Scope mode.
Recording waveforms To stop waveform recording, press “STOP”
Recording waveforms After pressing “STOP”, the above message will be displayed
Replaying the recorded waveform.
Replaying recorded waveforms To replay the waveforms, Press the left arrow. Progression indicator.
Recording waveforms To Pause the waveforms, Press the Pause. Waveform Paused.
Recording waveforms To Save Recorded waveforms to the VG hard drive, Press “FILE”.
Recording waveforms After pressing “SAVE” the above message will be displayed whilst saving. Previously “saved” recordings can be found by pressing “OPEN”.
Zooming recorded waveforms Previously recorded waveforms can be “Zoomed” in or out for better viewing by pressing “ZOOM”. Time base zoomVoltage zoom
Recording waveforms Waveforms can be zoomed, both in voltage and time, by touching the arrows above.
Recording waveforms Note here that the time base has been divided by 2, making the time base 5 ms / div instead of 10 ms as it was when recorded. It may also be multiplied
Recording waveforms Note here that the voltage scale has been multiplied by 2, making the Voltage 1v / div instead of 2v as it was when recorded.
Trigger Settings Before discussing the various possible trigger settings available on the Carman Scan VG, it should be noted that in most cases the VG user doesn’t have to make any changes at all to trigger settings. This Powerful, user friendly Oscilloscope automatically sets all the basic scope settings ready for testing by any user, whether highly experienced or a total novice.
Setting a Trigger point on an Oscilloscope, gives the scope a reference point at which to start the pattern display on the screen. The trigger point can be set at any position, and on any channel of the scope. An example of using a trigger would be: When displaying Secondary Ignition patterns, the “trigger” pickup is attached to # 1 HT lead. This means that the first cylinder to be displayed on the screen will be # 1 (the trigger cylinder) followed by the remaining cylinders in the firing order. If we removed the trigger pickup, the patterns may still be displayed, however, there would be no way of identifying the correct cylinders on the screen as the scope would have no reference point.
When using a Lab scope, setting a trigger point will keep the pattern steady on the screen. If measuring signals on more than one channel at a time, the trigger can be set on any channel. Triggered signals on one channel can be referenced against signals on other channels for exact timing etc. E.G.1 Using a Trigger pickup on # 1 HT lead, you can reference exactly when # 1 spark plug or coil is being fired in relation to the Crankshaft Position Sensor (being measured on another channel). E.G.2 When testing the timing of the Camshaft Position Sensor to the Crankshaft Position Sensor, triggering the two patterns together will allow you to check the exact position of the sensors in relation to each other, without physically removing any parts.
Checking timing of CMP to CKP Sensors Crankshaft (CKP) and Camshaft (CMP) Sensors. Checking correct timing of CMP Sensor
Trigger Settings (Note: a trigger gives the scope a reference point, allowing the pattern to be repeated over and over again at the same position on the screen) Making changes to the trigger settings can be done by either touching the appropriate section on the screen or by touching “TRIGGER” Trigger on channel 1
Trigger Settings To change trigger settings select one of the above. Trigger on channel 1
Trigger Settings : After touching “TRIGGER” the following selections can be made. Changing the Trigger channel - Touch “CHANNEL” or touch the screen here. Trigger now on channel 2
To move the trigger point to a new position, simply touch the screen in the upper left section and drag the trigger point to a new position on the scope. Trigger Point Trigger Settings : Moving the Trigger Point. Drag this to wherever you want
Trigger Settings : Changing the Trigger Type Oscilloscope triggered on a “Rising” signal. To make the oscilloscope trigger on a falling signal, touch “TYPE” or touch the screen here. Triggering on a rising signal
Trigger Settings : Changing the Trigger Type Oscilloscope now triggered on a falling signal. Triggering on a falling signal
The “mode” used to trigger the scope can be changed to suit the user or the test being performed. Trigger Modes available include: 1. “Auto” Mode ( 1. “Auto” Mode (Default mode) In this mode the VG automatically displays the pattern, regardless of the Trigger level selected. 2. “Normal” Mode In this mode the pattern will not be displayed until the “preset” trigger voltage has been reached. If selected whilst patterns are currently being displayed, the patterns will be frozen on the screen until the correct trigger level has been set. 3. “Single” Mode (Snap-shot mode) In this mode the VG automatically freezes the patterns on the screen as soon as the correct trigger voltage has been reached.
Trigger Settings : Changing the Trigger Mode. To change the trigger mode from ‘Auto’ to ‘Normal’, touch “MODE” or touch the screen here.
Trigger Settings : Changing the Trigger Mode. Trigger mode changed from ‘Auto’ to ‘Normal’. Touch again to change from ‘Normal’ mode to ‘Single’ mode
Trigger Settings : Changing the Trigger Mode. Trigger mode changed from ‘Normal’ to ‘Single’.
Trigger Settings : Changing the Trigger Mode. When in ‘Single’ mode, the scope will capture a single screen shot only. To display a new screen shot touch “Run/Stop”
Testing Injector Patterns To test an injector pattern, connect one of the lab scope leads to the Negative terminal of the Injector to be tested.
Testing Injector Patterns After selecting Inject… and the Channel # press “SAVE” to progress to Lab Scope screen. Press “SAVE” when completed
Testing Injector Patterns Typical Injector Pattern at Idle. To check the exact injector duration use the Cursors. Battery volts. Zero volts. Injector Off Spike ( Usually 70 – 100v). Battery volts. Injection Duration.
Testing Injector Patterns To use the Cursers touch “CURSER” once to bring up the first curser. Drag the first curser to the start of injection. Touch “CURSER” again for the second Curser. Drag the second cursor to the end of injection. Curser.# 1
The Injection duration (3.36 m/s is displayed as “SET TIME” at the bottom of the screen. The voltage difference is also displayed (13.25v) Second Curser. Testing Injector Patterns
Testing MAP and Throttle Position Sensors Engine drivability problems can often be caused by incorrect operation of MAP or Throttle Position Sensors. The Oscilloscope is an excellent way of testing both of these sensors for correct operation.
Testing Throttle Position Sensor and Map Sensor Signals After selecting the second channel press “SAVE” to progress to Lab Scope screen. Press “SAVE” when completed
Testing Throttle Position Sensor and Map Sensor Signals Throttle Position Sensor Signal Map Sensor Signal Check for smooth rise and fall in signals as accelerator is snapped open and closed. Maximum Vacuum during deceleration Full Throttle
Testing Throttle Position Sensor and Map Sensor Signals Approx 0.35v Approx 1.3v Approx 4.3v Approx 4.0v Approx 0.7v Typical Readings. Throttle Position Sensor Signal Map Sensor Signal
Testing Idle Control Motors Opening side Closing side
Testing Idle Control Motors With 3 wire type Idle Control Motors, the centre terminal is usually supplied with battery volts, while the two outside wires are switched to ground by the ECM using a variable duty cycle at a constant frequency. One side is the opening side and the other is the closing side. The duty cycle on one side is inversely proportional to the duty cycle on the other side. E.g. If the duty cycle on the opening side is 70%, the duty cycle on the closing side will be 30% and visa versa.
Opening Side = Approx 35% Closing Side = Approx 65% Testing ISC Duty Cycle Motor Type Off On Off On Testing IAC Motor at hot idle with no load.
Opening Side = Approx 42% Closing Side = Approx 58% Testing ISC Duty Cycle Motor Type Off On Off On Testing IAC Motor at hot idle with Air Conditioning on.
Testing Oxygen Sensors There are two main types of oxygen sensors used on vehicles today. 1. Zirconium (voltage generator type) 2. Titanium (variable resistor type) The following is a description of the testing procedure for a Zirconium Oxygen Sensor. As the Oxygen sensor is such an important part of the “Closed Loop” feedback system, it is extremely important that you have a thorough understanding of the correct testing procedures. A faulty Oxygen Sensor not only has a detrimental affect on vehicle emissions and fuel economy, it can also cause dramatic drivability problems.
Testing Oxygen Sensors
Selecting Oxygen Sensor Test After selecting the type of oxygen sensor and the channel Press “SAVE” to progress to Lab Scope screen. Press “SAVE” when completed
Good Oxygen Sensor Pattern at 2500 RPM 1 Second 5 Crossovers The “crossover” is the point where the 02 sensor signal crosses the midway (approx 500mv) point in the signal. The oxygen sensor’s speed is measured as the number of “Crossovers per Second” Rich Lean
Good Oxygen Sensor Pattern at Idle Note the slower speed of the 02 Sensor at idle. 1 Second 2 Crossovers
Bad Oxygen Sensor Pattern at 2500 RPM This may be caused by an over-rich air fuel mixture or a faulty (possibly contaminated) 02 sensor. 02 sensor voltage staying high (approx 800mv) To test if the 02 sensor is causing the fault, disconnect an injector and check for a sharp drop in the signal. If the signal drops sharply the 02 sensor is OK and the high signal voltage is caused by an over rich air fuel ratio.
Bad Oxygen Sensor Pattern at 2500 RPM This indicates that the high voltage is caused by an over rich air fuel ratio, not a faulty 02 sensor Sharp drop in 02 sensor voltage as injector is disconnected
Bad Oxygen Sensor Pattern at 2500 RPM 02 sensor voltage staying low (0v) This may be caused by a lean air fuel mixture, a faulty 02 sensor or grounded wiring. To test if the 02 sensor is causing the fault, snap the throttle rapidly a few times or feed some LPG into the intake. If the 02 sensor voltage now increases the 02 sensor is OK and the low signal voltage is caused by a lean air fuel ratio.
Bad Oxygen Sensor Pattern at 2500 RPM Sharp increase in 02 sensor voltage as throttle is snapped open a number of times. This indicates that the low voltage is caused by a lean air fuel ratio, not a faulty 02 sensor or grounded wiring.
Current Ramping There’s no doubt about the value of a current probe for quick accurate diagnosis. More and more technicians are now starting to realise the value and are using a low current probe to test things like: Fuel Pump operation/wear Fuel Pump operation/wear Ignition coil operation/available current Ignition coil operation/available current Coil on plug and DIS operation Coil on plug and DIS operation Injector operation/available current Injector operation/available current
Testing Fuel Pump Waveforms To test a fuel pump waveform, connect the low current probe around a single wire going to the fuel pump. (Using “Optional” Low Current probe). The electrical condition of a fuel pump can be assessed by viewing the current waveform for irregularities. Fuel Pump wear can be determined before complete failure occurs.
Testing Fuel Pump condition using VG Normal waveform for good Fuel Pump. Low current probe connected around fuel pump power supply wiring.
Testing DLI Ignition System using Low Current Probe Normal waveforms. #1 Trigger Pickup Signal # 1/4 Coil #1/4 Crank Angle Sensor Signal from 3 x sensor # 1 & 4 Spark Plugs firing here Dwell starts here # 3/6 Coil# 5/2 Coil Current Probe around coil power supply wire
AC Coupling Every signal we have tested up to this point has been with the Oscilloscope set to “DC” coupling. DC Coupling is the Default screen and is the best way to test most Sensors and Actuators etc. AC Coupling can be very valuable however for testing for “noise” on power supplies, checking Alternator diodes etc. or for testing Knock Sensor signals. Only Channel 1 can be AC Coupled
Channel 1 connected to vehicle battery with DC Coupling selected To select AC Coupling touch “AC”. Approx 14 volts 0 volts Note: Only Channel 1 can be AC Coupled. Note: Pattern is DC Coupled at this time
Channel 1 connected to vehicle battery with AC Coupling selected Approx 14 volts AC Coupled Note: To check for any fluctuations in battery voltage change voltage scale to either 50m/v or 100m/v per div. Pattern is now AC Coupled.
Channel 1 connected to vehicle battery with AC Coupling selected Approx 14 volts AC Coupled Note: To check condition of Diodes, load Alternator by operating accessories. Maximum variation should be approximately 300m/v Voltage scale set to 100mv/Div
Analysing by Trouble Type Another very Powerful feature of the Carman VG is a feature called “Analyse by Trouble Type”. With this feature, you can select from a list of possible faults or symptoms and the VG will automatically select the components to be tested for analysing the fault. Each component will be allocated a channel for testing and the Oscilloscope channels will be set up with appropriate voltage and time base settings.
Analysing by Trouble Type Touch the“Analyse by Trouble Type” Icon.
Analysing by Trouble Type After selecting the type of fault, the components requiring testing will be allocated their channels. Next select “SAVE” to progress to the Oscilloscope. Vehicle Fault Press “SAVE” when completed
Analysing by Trouble Type Next select the type of sensors on the vehicle (highlighted in bold) and touch “OK” to progress to the Oscilloscope.
Analysing by Trouble Type Oscilloscope channels are now set ready for testing of components.
In Conclusion The knowledge gained by attending this course can only be of benefit if put into practice as soon as possible. Specialists are not created overnight. They are created by PRACTICE and the willing to learn. Diagnostics is not magic, it perfected by applying BASICS. A knowledge of how a system or component operates is one of the most valuable tools when trying to diagnose a problem. Study the operation of various components and you will find that it won’t matter what type of vehicle you are working on. They all operate in a very similar manner.
Your Partners for the Road Ahead! and Carman Scan VG Nextech