Scan Tool Functional Tests Steve Zack, Jim Wilson, Ross Hayner

1. Scan Tool Functional TestsSteve Zack, Jim Wilson, Ross Hayner

2. Fuel Control Test

3. DataStream DiagnosticsFuel Control Test Clear Flood Equipped Vehicles A) DataStream • TPS • Injector Pulse Width B) KOEO C) WOT • TPS 4.3 To 4.7 Volts • Injector Pulse Width 0.0

4. Scan Tool Fuel Control Test(Easy to get HO2S) • 1) Disconnect HO2S • 2) Datastream • HO2S • Injector Pulse Width • 3) Volt Meter At HO2S Signal Return Wire at O2 sensor • 4) KOER, Engine At Operating Temperature, 1000 Rpm • 5) Place One Finger On PCM HO2S Signal Return Wire to the PCM • 6) Place Another Finger At Battery Positive • Datastream HO2S - 1 Volt • Datastream Injector Pulse Width - Will Drop • Volt Meter HO2S - 0 Volt • 7) Place Finger At Battery Negative • Datastream HO2S - 0 Volt • Datastream Injector Pulse Width - Will Rise • Volt Meter HO2S - 1 Volt

5. Scan Tool Fuel Control Test(Hard to get HO2S) • 1) Datastream • HO2S • Injector Pulse Width • 2) Propane enriching device • 3) KOER, Engine At Operating Temperature, 1000 Rpm • 4) Open propane bottle • Datastream HO2S - 1 Volt • Datastream Injector Pulse Width - Will Drop • 5) Close propane bottle • Datastream HO2S - 0 Volt • Datastream Injector Pulse Width - Will Rise

6. Lambda Fuel Trim Tests

7. Fuel Trim/Lambda • Graph STFT • Graph LTFT • Add together to get the actual Fuel Trim • Compare to the LAMBDA Reading on the GAS Analyzer • If readings are 1.0 on LAMBDA and near O% Actual Fuel Trim the vehicle is running correctly

8. LAMBDA at 1.04 slightly lean readings LTFT -3.9% both banks STFT 0% both Banks Actual Fuel Trim Correction -3.9% LAMBDA/Fuel Trim

9. Snap the Throttle WOT, TPS is 4.47V Power Enrichment is Active It takes time for the gases to flow through the Gas Bench LAMBDA is at .96 at the red arrow showing power enrichment LAMBDA/Power Enrichment

10. Ford Fuel Pressure Tests

11. Ford Electronic Return-less Fuel System • Fuel Rail Pressure Sensor measures pressure difference between fuel rail and the intake manifold • Fuel Pump Duty Cycle • This reading is half the fuel pump driven duty cycle

12. O2 Sensor Tests

13. 2004 Pathfinder Software Custom Display 7 Samples per Second Highlight, Select and Graph HO2S Bank 1 Sensor 1 Perform for each front fuel trim O2 sensor Specification for Good O2 Sensor: 10 cycle from 200mv Lean to 800mv Rich and then Rich to Lean in 1 second, at 2000 RPM hot engine 149 frames divided by 7 samples second equals 21.25 O2 Sensor cycles from 200mv Lean to 800mv Rich and then Rich to Lean, at 2000 RPM hot engine 02 Sensor Testing

14. Propane enrichment testing to check that the O2 sensors are working properly Select, graph and zoom the O2 sensors Propane enrichment increases the O2 output above .91 volts, preferred is closer to 1.0 volt. Keep adding propane until RPM decreases, to get the maximum output Remove the propane to see how fast the voltage decreases. It should decrease in a straight line HO2S S2 did not and should be replaced O2 Sensor Propane Test Good O2 Bad O2

15. Bi-directional Tests

16. Bi-Directional Test(Example Injector Control) (Use to verify possible misfire) • 1) KOER • 2) Setup datastream to read • Injector Pulse Width • HO2S • RPM • 3) With scan tool control injector • Injector off pulse width should drop • RPM should drop • HO2S should drop

17. Bi-directional Functional Test • 1) Turn Device Normally Off To On • 2) Device Activated • A) Ok Electrically • 1) Problem May Be Mechanical • 3) Device Does Not Activate • A) Test B+ At Device • 1) Ok, Go To Step B) • 2) Bad, Repair B+ Circuit • B) Test B- At Device • 1) Ok, Replace Device

18. Injector Testing

19. Chrysler Bi-Directional Testing • Special Test • Install Fuel Pressure • ATM - Automatic Test Mode • Injector • Press “Activate” soft key • Fuel Pressure should drop • 20% is the max variable from injector to injector

20. EVAP Testing

21. GM EVAP Test • Remove fuel cap and verify tank pressure voltage should be 1.3 to 1.7 or 0 inH2O • Using vent solenoid bi-directional test block venting operation • Apply vacuum to system using engine vacuum or an external vacuum source • Obtain 5” of vacuum using tank pressure sensor reading • Pinch off vacuum source and seal system • Monitor fuel tank pressure for 5 minutes in graph mode (Connectech preferred for longer record times) • If decay is present save recorded time and decay info. • Apply smoke to pinpoint leak or apply very light pressure to system • Use HC on a 5 gas analyzer to pinpoint leak. • Repair and retest decay of system and compare to previous recording • System Performance test is also available if certain conditions are met

22. Ford EVAP Test • Key ON Engine Off • Remove the connector from the Vacuum Management Valve • Use the Special Menu then go to Output Controls and select All Outputs on • Use the EVAP Test Port and perform the pressure test with the EVAP Tester

23. Air Pump Testing

24. Electric Air Pump Test • Scroll to “Special Tests”, press “Enter” • Scroll to “Engine Controls”, press “Enter” • Scroll to “Air Pump”, press “Enter” • Press “More” and scroll to “Select”, press “Enter” • Scroll to “HO2S Data”, press “Enter” • Scroll and high light HO2S Bank 1 & 2 Sensors 1& 2 • Press “More”, scroll “To Top”, press “Enter” for each HO2S sensor • Press “Start” then “On” to activate Air Pump • Front O2 sensors should switch below 200mv and remain there until Air Pump is deactivated.

25. EGR Testing

26. EGR Functional Test(Bi-directional) • 1) Engine At Operating Temperature, KOER • 2) Scan Tool Datastream • EGR Percentage • Injector Pulse Width • HO2S • MAP voltage • RPM • 3) With scan tool open EGR valve • 6) Datastream • EGR Percentage, High • Injector Pulse Width, Drop • HO2S increase • MAP voltage should rise • RPM should drop

27. EGR Bi-Directional TestGM Linear EGR • Scroll to “Special Tests” and press “Enter” • Scroll to “EVAP/EGR” and press “Enter” • Press “More” and scroll to “Select” • Press “Enter” and scroll to “EGR Data” • Press “Enter” • Scroll and high light EGR Normalized Position Data • Press “Start” and “Increase” EGR percentage • EGR Commanded opening should be within 3% of actual Normalized Position

28. EGR Functional Test(Non-Bi-directional) • 1) Engine At Operating Temperature, KOER • 2) Scan Tool Datastream • EGR Percentage • Injector Pulse Width • HO2S • 3) Vacuum Gauge At EGR Valve Vacuum Hose • 4) Lab Scope On EGR Solenoid • 5) Bring Engine RPM To 2000 Loaded • 6) Datastream • EGR Percentage, High • Injector Pulse Width, Drop • HO2S increase • 7) EGR Vacuum, 3 Inches Or Higher • 8) EGR Solenoid, Lab Scope, Pulse To Ground

29. EGR Functional Test(FORD KOER) • 1) Engine At Operating Temperature, KOER • 2) Vacuum Gauge At EGR Valve Vacuum Hose • 3) Lab Scope On EGR Solenoid • 4) Perform KOER Test • 5) EGR Vacuum, 3 Inches Or Higher, Vacuum OK, Solenoid OK • 6) EGR Solenoid, Lab Scope, Pulses To Ground, Duty Cycle, Solenoid OK • 7) Inspect EGR Passage For Carbon • This Test Can Be Performed On Any FORD Actuating Device, i.e. Injector, Idle Air Control, And EGR

30. FORD EGR Quick Test • FORD quick EGR test • Plug the EVR which is normally open • The port is under the cap on the EVR near the filter assembly • Port plugged RPM should drop as EGR opens • RPM does not drop, clean the EGR passages

31. Run the engine at idle and graph the EGR Delta Pressure Feedback Sensor Apply About 6 inches of Vacuum to the EGR The output should go above 4.0 volts FORD DPFE

32. Timing Advance Tests

33. GM CAM Retard Tests • GM CAM RETARD or CAM OFFSET PID • Spec is 0 degrees +/- 2 degrees for V8 engines • At hot idle monitor PID • Raise RPM to 1000 RPM after adjusting distributor to force computer to recalculate CAM Retard PID • Repeat steps until pid indicates 0 degrees

34. Datastream review of Timing Advance versus RPM The timing advance should follow RPM, except when in Wide Open Throttle, when timing advance decrease slightly Timing Advance Datastream Test

35. Datastream review of Timing Advance versus TPS TPS moves and Spark changes good reaction and timing curve Timing Advance Datastream Test

36. Datastream review of Timing Advance versus MAP The spark advance must follow the MAP sensor load changes Timing Advance Datastream Test

37. Secondary Ignition Tests

38. Chrysler Bi-Directional Testing • Special Test • Install Secondary Ignition Tester • ATM - Automatic Test Mode • Ignition Coil • Press “Activate” soft key • Secondary Voltage should read 4K to 7K

39. MAF Sensor Tests

40. MAF Test • 1) KOER, Engine At Operating Temperature • 2) Scan Tool Datastream • MAF GPS • (Frequency May Be Substituted For GPS) • 3) Mark Points Of MAF GPS On Graph Paper • 1000 Rpm • 1250 Rpm • 1500 Rpm • 1750 Rpm • 2000 Rpm • 4) Connect Plot Points, Graph Line Should Rise Smooth

41. Good MAF Graph GPS RPM 1000 1250 1500 1750 2000

42. Bad MAF Graph - Out of Calibration GPS RPM 1000 1250 1500 1750 2000

43. Bad MAF Graph - Air Leak GPS RPM 1000 1250 1500 1750 2000

44. Select and graph RPM and MAF Ford MAF sensor should reach a output of above 3.5 volts with a snap throttle This sensor did not reach the output and needed to be cleaned or replaced MAF Test

45. GM with a snap throttle should go above the 5.4 kHz for a good sensor output Check MAF sensing wires or clean the wires, and check the duct work for leaks after the MAF sensor GM MAF TEST

46. MAP Sensor Tests

47. MAP Sensor Test • 1) Scan Tool Datastream • Map Sensor Voltage • 2) KOEO • 3) Attach Vacuum Pump To Map Sensor Vacuum Port • 4) 0 Vacuum, 3.9 To 4.7 Volts • 5) 18 To 20 Inches Vacuum, .8 To 1.5 Volts

48. Cranking Vacuum can be tested using the MAP Sensor The voltage or pressure should decrease in response to vacuum Cranking Vacuum/Pressure

49. Testing the TPS against the MAP sensor shows the response of the sensors They should follow each other. This test will verify CAM to Crankshaft timing This test will verify if the TPS sticks when closing MAP shows a good response to change and shows the engine is breathing correctly Reaction Testing

50. TP Sensor Tests