Scan Tool Test Procedures Steve Zack Technical Instructor Bosch AA-AS Steve Zack 8.10.15 1
This class will develop the technician skills to use their scan tool to resolve difficult technical issues efficiently. The class will show the technician how to test various components on a vehicle using Datastream or Special Tests As they master the navigation of their scan tool and learn how to research repair information, or by using OTC Auto Detect feature, when the repair information points them to test a component they will be equipped with the knowledge they have gained from this class to resolve the complex drivability issue Efficiency and productivity will improve with greater test procedure skills which help develop better diagnostic skills Steve Zack 8.10.15 2
The specification listed in the test procedures and displayed in the video will vary with every manufacturer, vehicle, and engine classification. Please consult Identifix and or the vehicle manufacturers service information. Most components will use similar test procedures from vehicle manufacturer to vehicle manufacturer with a change only in specifications. Always consult Identifix for the correct test procedures. Steve Zack 8.10.15 3
Contents To hotlink to a specific test, click on that you wish to view Steve Zack 8.10.15 4
While performing many of these tests, to obtain the fastest possible Datastream refresh rate, please select individual Datastream PID s you are using for your diagnostic strategy and display them only. Steve Zack 8.10.15 5
Purpose of this test is to test sensor function. KOEO the MAP Sensor should read approximately 4.6 volts at atmospheric pressure approximately, 14.7 PSI. KOER, idle and at operating temperature the MAP Sensor reading should be between 1 to 2 volts Slowly increase the RPM as you increase RPM MAP voltage should drop then rise back to normal levels Engine Vacuum ( hg) atmospheric pressure ( hg) = Scan Data Vacuum ( hg) Steve Zack 8.10.15 6
Purpose of this test is to test sensor function. KOEO attach a hand held vacuum pump to the MAP Sensor nipple. Readings should match your altitude. The Voltage output varies with Altitude and Vacuum at the sensor. Low Altitude = High Pressure = High Voltage KOEO Steve Zack 8.10.15 7
Purpose of this test is to verify engine performance. Testing the TP against MAP sensor shows the response of the sensors. Snap the throttle wide open, KOER. They should follow one another. This test is also used to check; 1) TP sensor reaches wide open throttle readings. 2)TP sticks when closing. 3)MAP shows a good response to change and shows a good breathing engine. Steve Zack 8.10.15 8
Purpose of this test is to verify engine performance. Testing the TP against MAP/MAF and Spark Advance shows the response of the sensors. Slowly increase engine RPM from 1000 to 2000 RPM. They should follow one another. The test results show good response to increase engine RPM and shows a good breathing engine. Steve Zack 8.10.15 9
Purpose of this test is to test sensor function. Graph TP Sensor on the Scan Tool. It will also record the min and max voltages along with a voltage setting that the vehicle must exceed for wide open throttle. Open and close the throttle slowly the graph should rise and fall linear, smoothly and without skipping. Steve Zack 8.10.15 10
Purpose of this test is to test sensor circuit. Reference Voltage for the sensor should range between 4.9 to 5.1 volts. Check for proper ground at the three wire sensor, it should be under.050 volts. Short the VREF to the signal wire, it should register the reference voltage at the scan tool. This checks the Voltage supply circuit and the PCM ability to read the signal. Shorting the signal to ground checks the ground circuit, the scan tool will display 0. Steve Zack 8.10.15 11
Purpose of this test is to test temperature sensor circuit. The voltage supply should be 4.6 volts or above. Some computer systems will display a reading of around 40ºF at the Scan Tool when the connector is disconnected. Second test is to check if there is a good ground circuit back to the computer. Short across the connector and check the voltage, it should be under.050 Volts. This will show at the Scan Tool as 0 volts. Some vehicles reading for a shorted connector will be above 290º F. This indicates a good ground for the sensor all the way back to the computer. Some vehicles will use a default reading when performing this test, make sure the voltages readings are correct. Steve Zack 8.10.15 12
Purpose of this test is to test sensor function. Graph the MAF in GPS, Frequency or Voltage to allow plotting of readings. Pick one and graph the readings at 250 RPM increments from 1000 RPM. The graph plot points should be in a straight line. Once you have learned how to perform this test on paper you will eventually be able to use the graphing feature on the tool. Steve Zack 8.10.15 13
This graph show a good MAF as it increases with speed in linear graph pattern. The TP and MAF should follow each other with RPM increases. Adding a graph reading of Long Term Fuel Trim - LTFT will give an idea if the MAF is out of calibration. If there is large difference in the LTFT from idle to cruise, could mean there is a contaminated MAF sensor. Green graph means good test results. Once you have learned how to perform this test on paper you will eventually be able to use the graphing feature on the tool. Steve Zack 8.10.15 14
This graph would give low power or acceleration symptoms. The MAF Sensor output increases too fast in reaction to increase in RPM. The PCM would quickly increase injector pulsewidth at the lower end of the RPM scale causing a acceleration problem. The MAF Sensor may be out of calibration or contaminated. Red graph means bad test results. Once you have learned how to perform this test on paper you will eventually be able to use the graphing feature on the tool. Steve Zack 8.10.15 15
Check for dirty sensing wire on the MAF Sensor. This graph shows either a dirty sensing wire or an air leak downstream of the MAF Sensor, as a result the extra air at the leak is unmeasured. Red graph means bad test results. Once you have learned how to perform this test on paper you will eventually be able to use the graphing feature on the tool. Steve Zack 8.10.15 16
Purpose of this test is to test sensor function. KOEO the MAF sensor should read 0.0 GPS KOER, idle and at operating temperature MAF should read 2 to 7 GPS Slowly increase engine RPM and MAF value should rise At 2500 RPM the MAF should read 15 to 25 GPS or 2k to 3k Hz Steve Zack 8.10.15 17
Purpose of this test is to test sensor function. While Data Stream, Highlight, Select and Graph HO2S Bank 1 and 2 Sensor 1. Specification for a Good O2 Sensor: 10 cycles, 1 each of rich and then lean, from 200mv Lean to 800mv Rich and return to lean from 800mv to 200mv for a total of 10 in 1 second, at 2000 RPM hot engine, each swing up or down must be completed in less than 100ms. OBD II Global 2 samples second 92 seconds record time with a minimum of 9 O2 Swings up and down. OBD II OEM 4 Samples Second 46 seconds record time with a minimum of 5 O2 swings up and down. CAN OEM 7 samples second 26 seconds record time with a minimum of 3 O2 swings up and down. Frame/sample rate=seconds/10=o2 swings Steve Zack 8.10.15 18
Purpose of this test is to test sensor function. Perform a propane enrichment test to see if the O2 sensor is working properly. Graph the front O2 sensors, HOS1/1 and HOS2/1, fuel control sensors. Propane enrichment increases the O2 output above.91 volts, or higher towards 1.0 volts. Keep adding propane until the RPM decreases to obtain the maximum output. Then remove the propane to see how fast the voltage decreases. It should decrease in a straight line. Steve Zack 8.10.15 19
Purpose of this test is to test sensor function. With the ignition ON and the engine running (KOER), allow to warm to normal operating temperature. Once the engine is at normal operating temperature, go to the next step. Upstream oxygen sensors should switch from rich to lean every few seconds. The voltage should toggle between 400-700 mv and never be a negative value. Steve Zack 8.10.15 20
The purpose of this test is to verify the functionality of an AFR Sensor. The AFR will only function if the AFR heater has reached operating temperature of 1200 F. The engine must be at operating temperature and there must be no DTC s present for the AFR or the AFR Heater circuit while performing this test. From idle, raise engine to 2500 RPM, the AFR should read 3.30 volts for Enhanced data and 0.66 volts for Global OBD II. Snap the throttle to 4000 RPM and the AFR will read 2.50 volts for Enhanced data and 0.50 volts for Global OBD II. The PCM will maintain positive amperage. This is a Rich condition. After the throttle is closed and the engine has return to an idle, the AFR voltage should rise to 3.80 volts for enhanced data and 0.78 volts for Global OBD II. The PCM will compensate with negative amperage. This is a Lean condition. If no change during this test, check the AFR heater circuit. The PCM will control the amount of amperage to maintain stoichiometric throughout the drive cycle. When a rich command occurs the PCM will supply positive current to the AFR, when a lean command occurs the PCM will supply negative current to the AFR. The PCM will convert the amperage supplied to the AFR for Datastream as a voltage reading. Datastream specifications vary from manufacturer to manufacturer; please check Identifix for the specification. Steve Zack 8.10.15 21
Purpose of this test is to test sensor function. KOEO the scan tool data should read 0 KOER the scan tool data should vary with RPM Slowly increase RPM and CMP data should change and rise and fall with RPM Steve Zack 8.10.15 22
Purpose of this test is to test sensor function. KOEO the scan tool data should read 0 KOER the scan tool data should vary with RPM Slowly increase RPM and CKP data should change and rise and fall with RPM Steve Zack 8.10.15 23
Purpose of this test is to test sensor function. KOEO, engine at operating temperature Remove the Fuel Cap With the Fuel Cap off data readings should be 2.4 to 2.8 volts GM 1.4 to 1.6V Ford 2.4 to 2.7V Toyota 3.0 to 3.6V Steve Zack 8.10.15 24
Purpose of this test is to test sensor function. KOEO, engine at operating temperature. KOEO the data readings should be 0. Tap on the engine surface near the Knock Sensor using a hammer or solid object. When tapping the readings should decrease to 0 to 16 degrees. Steve Zack 8.10.15 25
Purpose of this test is to test sensor function. Raised the vehicle off the ground, with vehicles equipped with traction control disable that first using the switch on the dashboard or shift lever. Slowly increase vehicle speed. Datastream VSS data should equal vehicle speed. Steve Zack 8.10.15 26
The purpose of this test is to verify fuel pressure versus Fuel Rail Pressure sensor values. Fuel Rail Pressure Sensor measures pressure difference between fuel rail and the intake manifold Fuel Pump pressure will be higher than the readings at the FRP Sensor. Divide the vacuum reading by two to get the pressure drop from vacuum. 20 divided by 2 = 10psi. 10 PSI plus scan tool reading gives correct pressure. If we are at idle, with 20 vacuum, which equals -10PSI and have 30 PSI at the FRP, the fuel pressure at the gauge should read 40 PSI. 30 PSI+10PSI = 40PSI Instead of using engine vacuum to a pressure regulator under the hood, the system uses engine data and varies the speed of the pump to meet fuel requirements. The pump is energized with pulse-width modulated voltage. This means that if you connect your voltmeter to the fuel pump circuit, the readings will bounce around instead of being a constant voltage. Steve Zack 8.10.15 27
PCM Control Tests Steve Zack 8.10.15 28
http://www.otctools.com/ve Volumetric Efficiency is the verification of an engines performance calculated from the amount of Air used. Performing a VE test can reveal the accuracy of a vehicle's Mass Airflow Sensor, more importantly it can quickly diagnose drivability issues. Essentially you will be able to determine the area of cause of a drivability problem much faster. It will help you to determine if you are dealing with a Fuel, Air, Exhaust or Mechanical issue without spending hours trying to determine the direction to start your diagnosis. It is the key to successfully diagnosing and fixing a vehicle efficiently making, you more money Your Datastream reading during the WOT need to be recorded and inputted to the calculator from the scan tools data (RPM, IAT and MAF) at the same time frame of the highest RPM obtained VE specification = 75% to 90%. Steve Zack 8.10.15 29
There are a few things you will need to do first to perform a Volumetric Efficiency Test: Find a good road test area Safe from pedestrians and other vehicles Where you can perform a WOT road test It is important to learn how this test will perform in your area. Road testing a few vehicles to get a base line of what and how the test performs will help you with your diagnosis. Every test you perform will vary as the result of ambient conditions. Knowing how the test performs in your area will help you understand the results to expect from those variables MAF Mass Air Flow gs IAT Intake Air Temperature - F RPM When IAT reads in C, the PID will have to be converted Converting C to F: ( C x 1.8) + 32 = F The engine must be at operating temperature While performing many of these tests, to obtain the fastest possible Datastream refresh rate, please select individual Datastream PID s you are using for your diagnostic strategy and display them only Steve Zack 8.10.15 30
Engine Mechanical Test results: Very low VE STFT high Cause: Engine mechanical which would be caused by those components that would cause low compression, such as valve seating, burnt valves, piston rings, cam timing and cam lobes. Low compression results with STFT adding fuel because the PCM may think the engine is under a load due to lower than normal vacuum Conclusion: VE is a calculation of the amount of air going in, with low compression the engine will not be able to create a sufficient low pressure area behind the throttle plate for the atmospheric high pressure to overcome Perform this test to verify: MAP Steve Zack 8.10.15
MAF Test results: VE low MAF low STFT high Cause: MAF is not accurately reporting air volume. This may require cleaning the MAF hot wire, sensing wire or vane. It could also be a result of additional air entering after the MAF in the air stream as a result of a leak in the snorkel or intake manifold Conclusion: MAF measures the volume of air being consumed. If MAF reports incorrectly to the PCM, AVF calculation will be inaccurate. Inaccurate MAF readings will result with PCM correcting IPW for a lean condition Perform this test to verify: MAF Steve Zack 8.10.15
Fuel System Test results: VE low STFT high HO2S or AFR lean Cause: If STFT reads high and HO2S or AFR read lean you have a fuel related issue. This could be a result of a dirty fuel filter, low fuel pump pressure, low fuel pump volume and or restricted injector flow Conclusion: If the engine does not have enough fuel to add to the combustion chamber, power will be limited resulting in the pressure behind the throttle plates being lower than required. As a result, air volume during wide open throttle will be low. The HO2S or AFR sensor will report a lean condition at idle as a result of the low fuel volume and the PCM will compensate with adding fuel commanding plus number for Fuel Trim Perform these tests to verify: Fuel Trim HO2S AFR Steve Zack 8.10.15 33
Intake Restriction Test results: VE low STFT normal = 0 Cause: The intake restriction could be a result of a dirty air filter, animals nest in the snorkel or carbon on the intake valve throat Conclusion: Part of the VE calculation is the amount of air going in, AVF, and if there is an intake restriction before the throttle plate, atmospheric high pressure air will be blocked, limiting the air needed to overcome the low pressure area behind the throttle plate Perform this test to verify: MAF Steve Zack 8.10.15
Exhaust Restriction Test results: VE low STFT normal or slightly negative Cause: Exhaust restriction could be a result of a plugged Catalytic Convertor or carbon on the exhaust valve throat Conclusion: Proper VE requires the air to exhaust out, if there is an exhaust restriction the volume of air required for the engine to create sufficient power will not be able to enter Perform this test to verify: Catalyst Test Steve Zack 8.10.15
PCM Control Tests Steve Zack 8.10.15 36
Possible cause of Short Term Fuel Trim - STFT - fuel trim that is out of calibration. OBD II O2 monitor may pass yet the vehicle exhibits drivability complaints or fails emissions. Even though the O2 sensor is switching slowly the OBD II monitor only looks at 1.1 times per second as good. The minimum for true catalyst function is 1 time in less than 100ms. +10, + plus numbers on STFT means the PCM has received a lean signal from the HO2S sensor and the PCM will command the Injector Pulse Width to widen for a rich correction. -10, - minus numbers on STFT means the PCM has received a rich signal from the HO2S sensor and the PCM will command the Injector Pulse Width to narrow for a lean correction. Steve Zack 8.10.15 37
Purpose of this is to verify PCM Fuel Control based on sensor input. Graph TPS and IPW. Watch the TPS and Injector Pulse-Width at the same time while slowly opening the throttle. At about 4.3 to 4.7 volts on the TPS the Injector Pulse-Width should be at O on vehicles that support Clear Flood Mode. This test sees if the PCM has Fuel control capabilities based on TPS input. Chrysler vehicles will clear flood at 2.60 volts above stored minimum TPS voltage. Steve Zack 8.10.15 38
Purpose this test is to verify PCM Fuel Control based on O2 input. Using the battery and the resistance of your body, touching the Positive battery post and the signal return wire to the PCM will give a signal of about 1 Volt. The injector pulse-with should decrease as the PCM sees a Rich condition leaning the mixture. Touching the Negative battery post will send a lean O2 signal to the PCM, which then increases Injector pulse-width to richen the mixture. Check for DTC that may be set by performing this test, and clear them as necessary. Steve Zack 8.10.15 39
Purpose this test is to verify PCM Fuel Control based on O2 input. Add propane to create a rich mixture, the O2 voltage will rise and the PCM will decrease injector pulse width, STFT numbers will decrease. When the propane is turned off the mixture will be lean, O2 voltage will drop and the PCM will increase injector pulse width, STFT numbers will increase. Steve Zack 8.10.15 40
PCM Output Tests Steve Zack 8.10.15 41
Purpose of this test is to test Injector function. KOEO, engine at operating temperature, Injector Pulse Width - IPW should be 0 ms KOER, engine at operating temperature, IPW should be 4 to 15 ms Slowly increase RPM and the IPW should also increase Steve Zack 8.10.15 42
Purpose test is to determine the cause of a cylinder misfire. Tests for clogged injectors or Ignition Misfire by watching the rear O2 sensor output. Monitor rear or post cat HO2S Base line voltage.430mv to.470mv If rear HO2S voltage is high; Secondary Ignition miss fire If rear HO2S voltage is low; Lean Injector miss fire Note: Rear HO2S voltage can be low due to an exhaust leak Steve Zack 8.10.15 43
Purpose of this test is to verify Catalytic function. The upstream O2 sensor should vary from under 200mV to above 800mV switching high and low. A good catalytic converter will keep the downstream O2 sensor switching in a very narrow range. A post cat HO2S switching high to low would indicate the cat is not functioning A post cat HO2S that displays high voltage is not oxidizing HC & CO A post cat HO2S that displays low voltage is not storing the O2 An exhaust leak will create false readings Steve Zack 8.10.15 44
The purpose of this test is to test for a plugged Catalytic Converter. Highlight and graph MAP Voltage. With the engine running at 2000 RPM for 3 minutes, note what MAP Voltage is, it should be around 1.2 to 1.6 Volts. Snap the throttle to wide open from 2000 RPM. MAP Voltage will rise from 2000 RPM at wide open throttle to approximately 3.8 to 4.2 Volts. When the engine returns to idle MAP Voltage should return to the 1.2 to 1.6 Volts in less than 3 seconds. If it takes longer than 3 seconds the Catalytic Converter may be plugged. If the MAP PID is not available go to Global OBD II and select Engine Calculated Load PID. With the engine at operating temperature and at idle record Calculated Load, typically 20 to 40%. With the engine at 2000 RPM snap the throttle wide open, the Calculated Load will immediately climb to 100%. When the throttle closes Calculated Load will drop to 0% and it should return to the idle reading in less than 3 seconds. Steve Zack 8.10.15 45
The voltage at idle should exceed 13.0. Many OEM s will give a target charging voltage. Turn all accessories on to create a demand on the charging system, to increase Alternator output. Steve Zack 8.10.15 46
GM/Chrysler/Ford are equipped with clear flood, turn key to on, press throttle to floor, then crank, if clear flood equipped it will not start. Non clear flood equipped vehicles pull the fuel pump fuse or relay. Ford, in the trunk or in the right kick panel is a Fuel Pump Roll over relay, inertia switch, at the top is a button which on running car will be in set about 1/4", slam it with your fist and the button will pop up, and the fuel pump is now disconnected. crank the engine to clear the rail of fuel before starting the test. at the end of the test push the button in to start the engine. Crank the engine for 15 seconds. Start the engine, and immediately apply load with turning all accessories on, I.e. head lights, high beams, emergency flashers, rear defroster, blower fan, and then increase the engine speed to 2000 RPM Battery voltage should exceed 13.0 Steve Zack 8.10.15 47
The purpose of this test is to check battery condition and as a battery sulfation test. Note the Voltage before beginning this test. GM/Chrysler/Ford equipped with clear flood, turn key to on, press throttle to floor, then crank, if clear flood equipped it will not start. Non clear flood equipped vehicles pull the fuel pump fuse or relay. Ford, in the trunk or in the right kick panel is a Fuel Pump Roll over relay, inertia switch, at the top is button which on running car will be in set about 1/4", slam it with your fist and the button will pop up, and the fuel pump is now disconnected. crank the engine to clear the rail of fuel before starting the test. at the end of the test push the button in to start the engine. Crank the engine for 15 seconds. The cranking Voltage should not go under 9.6 volts for a good battery and system. Recovery Voltage should come close to beginning voltage at the start of the test in less than 7 seconds. A long recovery time indicates a battery that may need to be replaced. Steve Zack 8.10.15 48
Possible cause of IAC Counts out of calibration. IAC Counts can indicate a problem with the Idle Air Control, if it is too high the throttle may need cleaning. PCV problems can cause a low or high IAC Counts depending on the flow through the PCV, be sure the correct PCV has been installed. Low IAC Counts less than 6 may indicate a vacuum leak. Ford uses percentage, specifications are 10 to 40%, 20 to 35% is preferred. +10, + plus numbers on STFT means the PCM has received a lean signal from the HO2S sensor and the PCM will command the Injector Pulse Width to increase for a rich correction. -10, - minus numbers on STFT means the PCM has received a rich signal from the HO2S sensor and the PCM will command the Injector Pulse Width to decrease for a lean correction. Steve Zack 8.10.15 49
The purpose of this test is to use bi-directional testing to check the electrical and mechanical condition of a device. Injector balance test are used to determine injector fuel flow for rough running conditions and misfires. This is available in Special Tests under Fuel Control. Setup the screen to read and graph the Injector Pulse-Width, HO2 sensor for that bank, and the RPM. The injector disable test allows turning off injector to watch for a RPM loss and a decrease in Oxygen sensor readings. Steve Zack 8.10.15 50
The purpose of this test is to use bi-directional testing to check the electrical and mechanical condition of a device. This test determines which circuit is at fault or if there is a mechanical error. Use a DVOM along with your scan tool for this test. The Power feed must be checked first at the B+ side of the device, it needs to be at battery voltage. The device must have proper voltage supply and ground to work. The Next step, check the B- (ground) side of the device it needs to be at battery voltage KOEO. Activate the device and the voltage must go under 200mv when ground is supplied by the PCM. If there are no voltage changes, then the device is bad or there is a bad ground control circuit. Check the path from the device to the PCM, if it is OK then there may be a bad driver in the PCM. Steve Zack 8.10.15 51
The purpose of this test is to the EVAP Canister Purge Solenoid. KOEO, data should read 0% or 0Hz KOER, engine at operating temperature, idle data should read 0 to 10Hz or 0 to 100% You may have to drive the vehicle, or raise the vehicle and place in drive with a load on the engine at speed of 35 mph. If you raise the vehicle you should disable the traction control system. Steve Zack 8.10.15 52
The purpose of this test is to the EVAP Canister Vent Valve. KOER, Engine at operating temperature, EVAP should be closed with Purge Valve On and EVAP Pressure sensor should read a vacuum if equipped You may have to drive the vehicle, or raise the vehicle and place in drive with a load on the engine at speed of 35 mph. If you raise the vehicle you should disable the traction control system. Steve Zack 8.10.15 53
The purpose test verify air pump function. Activates air pump test and verify front 02 sensors simultaneously switch to or below 200mv and stays there until pump is deactivated or until it deactivates itself after 30 seconds. If only one 02 sensor goes lean inspect the other sides vacuum line, solenoid or valve If both front 02 sensors still cycle from rich to lean inspect common air hose or pump pressure Steve Zack 8.10.15 54
The purpose of this test is to test the EGR system. KOEO, EGR Solenoid data should read 0% or 1.3V KOER, engine at operating temperature, idle data should read 0% or 1.3V Drive the vehicle, or raise the vehicle and place in drive with a load on the engine at speed of 35 mph, at cruise speed, data should read 0 to 100% or 0 to 5V Steve Zack 8.10.15 55
The purpose of this test is to use bi-directional testing to check the electrical and mechanical condition of a device. Display on Datastream the following PIDS: EGR, Injector Pulse-Width, HO2s, MAP Voltage, RPM Use the special test function to open the EGR and watch for: EGR Duty cycle to increase Injector Pulse-width to decrease HO2s should show an increase in voltage indicating a rich condition initially The MAP sensor should show an increase in pressure as the EGR opens (voltage increases). The RPM will drop in proportion to the percentage of the EGR opening indicating flow of the EGR. Steve Zack 8.10.15 56
The purpose of this test is to use bi-directional testing to check the electrical and mechanical condition of a device. Verify actual and commanded percentages are the same at idle. Increase EGR percentage while monitoring actual or normalized position PID. Numbers should match within 3% of each other through the full range. Verify reprogramming has been done (instead of just shutting off the EGR valve the PCM s new software will bounce the valve a few times if the at-rest position is not completely closed.) Typically if closed positions are not reading 0% then carbon may be holding the valve slightly open. By performing this test it temporarily allows the carbon to pass until the next occurrence. Steve Zack 8.10.15 57
The purpose of this test to verify EGR function. Display on Datastream the following PIDS: EGR Percentage, Injector Pulse-Width, H02S Use a vacuum gauge to monitor the EGR vacuum supply by teeing into the supply hose. Ported vacuum is used for the EGR and must be greater than 3 inches for proper operation. Use a lab scope or DMM on the ground side of the solenoid to monitor the duty cycle of the EGR solenoid. Perform this test at 2000 RPM while providing a load, or during a road test. Steve Zack 8.10.15 58
The purpose of KOER test is to activate components to check the function and validity of the components. The Lab scope will show the duty cycle of the solenoid as it is turned on and opened up. Use a DVOM to measure and read duty cycle to monitor the EGR, if a lab scope is unavailable. If Vacuum and the duty cycle are correct then there may be a blockage in EGR flow. Use Component Parameters - MODE 6 to test for the amount of EGR flow to determine if the EGR passes monitor test limits. Steve Zack 8.10.15 59
The purpose of this test to verify EGR flow. Plug off the EVR, which is normally open. This port is under the Cap on the EVR near the filter assembly of the EVR. Plugging off the port should cause RPM to drop as the EGR will open. If there is no RPM drop, clean the EGR passages. Steve Zack 8.10.15 60
The purpose of this test to verify EGR flow Start the engine and bring it to operating temperature. Hook up the scan tool and use data-stream readings for the DPFE sensor, HO2S and Engine RPM. Run the engine at idle and graph the EGR Delta Pressure Feedback Sensor. Apply 6 inches of Vacuum to the EGR. The DPFE output should increase above 4.0 volts. The RPM should decrease, and O2 voltage should increase. If RPM does not change, the EGR passage may be plugged. Steve Zack 8.10.15 61
Scroll to Special Tests and press Enter. Scroll to Actuator Tests and press Enter. Scroll to EGR Solenoid and press Enter. Disconnect engine vacuum from the solenoid and install vacuum pump to the engine side of the solenoid. Bring the vacuum pump to 18 inches of vacuum. Hook a volt meter to the negative side of the solenoid, voltage should be B+. Press the Activate soft key. Vacuum should drop to zero and voltage should towards zero. If not the solenoid may be plugged or may have an electrical error. If the voltage does not drop towards zero, the computer controlled ground signal may be at fault. Install a vacuum gauge on the engine manifold vacuum port of the EGR solenoid. Install the vacuum pump on the EGR valve. Start the engine. Engine vacuum should read approximately 18 inches. Bring the vacuum pump to 18 inches of vacuum and the EGR valve should open and the engine should run very rough and almost stall. If not the EGR passage is partially plugged. Steve Zack 8.10.15 62
To test for a no start that may be related to fuel systems, perform the following; Install a lab scope lead on the fuel pump relay ground control circuit. Install a lab scope lead on the fuel pump power circuit from the relay. Install a fuel pressure gauge Scroll to Diagnostic Trouble Codes and press Enter, scroll to Self Diagnostics and press Enter, scroll to KOEO Self Test and press Enter. At the start of the KOEO test the fuel pump relay ground circuit will show battery voltage until the PCM grounds the relay circuit to energize the pump, and the voltage will go to 0. The fuel pump power circuit at the start of the test should show 0 volts, and when the fuel pump relay is grounded the voltage should go to B+. Fuel pressure should rise to factory specification. Steve Zack 8.10.15 63
The purpose of this test is to use bi-directional testing to check the electrical and mechanical condition of a device. Injector balance test are used to determine injector fuel flow for rough running conditions and misfires. Special Test Install fuel pressure gauge. Scroll to Actuator Tests and press Enter. Then scroll to the Injector number to test and press Enter. Press the Ok soft key to accept the test, then press the Activate soft key to begin the test. Fuel Pressure should drop 20% is the max variable from injector to injector Steve Zack 8.10.15 64
The purpose of this test is to use bi-directional testing to check the electrical and mechanical condition of a device. Ignition Coil test are used to determine secondary ignition function for rough running conditions and misfires. Special Test Install Secondary Ignition Tester Scroll to Actuator Tests and press Enter. Then scroll to the Ignition Coil number to test and press Enter. Press the Ok soft key to accept the test, then press the Activate soft key to begin the test. Secondary Voltage should read 4K to 7K Steve Zack 8.10.15 65
3895 Genisys Touch 3893 Encore Steve Zack 8.10.15 66