2. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 OBJECTIVES After studying Chapter 13, the reader will be able to: 1.Prepare for ASE Electrical/Electronic Systems (A6) certification test content area “A” (General Electrical/Electronic Systems Diagnosis). 2.Explain the purpose and function of onboard diagnosis. 3.List the various duties of the diagnostic executive (task master). 4.List five continuous monitors. 5.List five noncontinuous monitors.

3. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 ON-BOARD DIAGNOSTICS GENERATION-II (OBD- II) SYSTEMS During the 1980s, most manufacturers began equipping their vehicles with full-function control systems capable of alerting the driver of a malfunction and of allowing the technician to retrieve codes that identify circuit faults. The automotive industry calls these systems On- Board Diagnostics (OBDs). The California Air Resources Board (CARB) developed the first regulation requiring manufacturers selling vehicles in that state to install OBD.

4. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 ON-BOARD DIAGNOSTICS GENERATION-II (OBD- II) SYSTEMS OBD Generation I (OBD I) applies to all vehicles sold in California beginning with the 1988 model year. It carries the following requirements: –An instrument panel warning lamp able to alert the driver of certain control system failures, now called a malfunction indicator lamp (MIL). –The system’s ability to record and transmit DTCs for emission-related failures. –Electronic system monitoring of the HO2S, EGR valve, and evaporative purge solenoid.

5. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 ON-BOARD DIAGNOSTICS GENERATION-II (OBD- II) SYSTEMS FIGURE 13-1 A typical malfunction indicator lamp (MIL) often labeled “check engine.”

6. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 ON-BOARD DIAGNOSTICS GENERATION-II (OBD- II) SYSTEMS The regulations for OBD-II vehicles state that the vehicle computer must be capable of testing for, and determining, if the exhaust emissions are within 1.5 times the FTP limits. To achieve this goal, the computer must do the following: –Test all exhaust emission system components for correct operation. –Actively operate the system and measure the results. –Continuously monitor all aspects of the engine operation to be certain that the exhaust emissions do not exceed 1.5 times the FTP. –Check engine operation for misfire. –Turn on the MIL (check engine) if the computer senses a fault in a circuit or system. –Record a freeze-frame, which is a snapshot of all of the engine data at the time the DTC was set. –Flash the MIL if an engine misfire occurs that could damage the catalytic converter.

7. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 DIAGNOSTIC EXECUTIVE AND TASK MANAGER On OBD-II Systems, the PCM incorporates a special segment of software. On Ford and GM systems, this software is called the diagnostic executive. On Chrysler systems, it is called the task manager. This software program is designed to manage the operation of all OBD-II monitors by controlling the sequence of steps necessary to execute the diagnostic tests and monitors.

8. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 MONITORS A monitor is an organized method of testing a specific part of the system. Monitors are simply tests that the computer performs to evaluate components and systems. Continuous Monitors –Comprehensive component monitor (CCM). –Misfire monitor –Fuel trim monitor –Noncontinuous Monitors

9. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 OBD-II MONITOR INFORMATION Comprehensive Component Monitor Continuous Running Monitors Once Per Trip Monitors Exponentially Weighted Moving Average (EWMA) Monitors

10. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 ENABLING CRITERIA Each monitor has enabling criteria. These criteria are a set of conditions that must be met before the task manager will give the go-ahead for each monitor to run. Most enabling criteria follow simple logic, for example: –The task manager will not authorize the start of the O2S monitor until the engine has reached operating temperature and the system has entered closed loop. –The task manager will not authorize the start of the EGR monitor when the engine is at idle, because the EGR is always closed at this time.

11. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 ENABLING CRITERIA Trip Warm-Up Cycle MIL Condition:Off MIL Condition: On Steady MIL Condition: Flashing MIL:Off

12. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 OBD-II DTC NUMBERING DESIGNATION A scan tool is required to retrieve DTCs from an OBD-II vehicle. Every OBD-II scan tool will be able to read all generic Society of Automotive Engineers (SAE) DTCs from any vehicle. FIGURE 13-2 OBD-II DTC identification format.

13. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 DIAGNOSTIC TROUBLE CODE PRIORITY CARB has also mandated that all diagnostic trouble codes (DTCs) be stored according to individual priority. DTCs with a higher priority overwrite those with a lower priority. The OBD-II System DTC Priority is listed below. –Priority 0—Non-emission-related codes –Priority 1—One-trip failure of two-trip fault for non-fuel, non-misfire codes –Priority 2—One-trip failure of two-trip fault for fuel or misfire codes –Priority 3—Two-trip failure or matured fault of non-fuel, non-misfire codes –Priority 4—Two-trip failure or matured fault for fuel or misfire codes

14. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 DIAGNOSTIC TROUBLE CODE PRIORITY OBD-II Freeze-Frame Freeze-frame items include: –Calculated load value –Engine speed (RPM) –Short-term and long-term fuel trim percent –Fuel system pressure (on some vehicles) –Vehicle speed (MPH) –Engine coolant temperature –Intake manifold pressure –Closed/open-loop status –Fault code that triggered the freeze-frame –If a misfire code is set, identify which cylinder is misfiring

15. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 ENABLING CONDITIONS OR CRITERIA Pending –Under some situations the PCM will not run a monitor if the MIL is illuminated and a fault is stored from another monitor. –In these situations, the PCM postpones monitors pending a resolution of the original fault. –The PCM does not run the test until the problem is remedied. Conflict –There are also situations when the PCM does not run a monitor if another monitor is in progress. –In these situations, the effects of another monitor running could result in an erroneous failure. –If this conflict is present, the monitor is not run until the conflicting condition passes.

16. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 ENABLING CONDITIONS OR CRITERIA

17. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 ENABLING CONDITIONS OR CRITERIA Suspend –Occasionally, thePCMmay not allow a two-trip fault to mature. –The PCM will suspend the maturing fault if a condition exists that may induce erroneous failure. –This prevents illuminating the MIL for the wrong fault and allows more precise diagnosis. Rationality Test –While input signals to the PCM are constantly being monitored for electrical opens and shorts, they are also tested for rationality.

18. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 ENABLING CONDITIONS OR CRITERIA Functionality Test –A functionality test refers to PCM inputs checking the operation of the outputs. Electrical Test –Refers to the PCM check of both inputs and outputs for the following: Open Shorts Ground

19. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 GENERIC OBD-II All OBD-II vehicles must be able to display data on a generic (also called global) scan tool under nine different modes of operation. These modes include: –Current power train data (parameter identification display or PID) –Freeze-frame data –Diagnostic trouble codes –Clear and reset diagnostic trouble code (DTCs), freeze-frame data, and readiness status monitors for noncontinuous monitors only –Oxygen sensor monitor test results –Onboard monitoring of test results for noncontinuously monitored systems –Onboard monitoring of test results for continuously monitored systems –Bidirectional control of onboard systems –Module identification

20. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 DIAGNOSING PROBLEMS USING MODE SIX Mode six information can be used to diagnose faults by following three steps: –Check the monitor status before starting repairs. This step will show how the system failed. –Look at the component or parameter that triggered the fault. This step will help pin down the root cause of the failure. –Look to the monitor enable criteria, which will show what it takes to fail or pass the monitor.

21. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 SUMMARY 1.If the MIL is on, retrieve the DTC and follow the manufacturer’s recommended procedure to find the root cause of the problem. 2.All monitors must have the enable criteria achieved before a test is performed. 3.OBD-II vehicles use a 16-pin DLC and common DTCs. 4.OBD II includes generic (SAE), as well as vehicle manufacturer-specific DTCs, and data display.

22. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 REVIEW QUETSIONS 1.What does the PCM do during a drive cycle to test emission-related components? 2.What is the difference between a type A and type B OBD-II DTC? 3.What is the difference between a trip and a warm- up cycle? 4.What could cause the MIL to flash?

23. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 1.A freeze-frame is generated on an OBD-II vehicle _____. a)When a type C or D diagnostic trouble code is set b)When a type A or B diagnostic trouble code is set c)Every other trip d)When the PCM detects a problem with the O2S

24. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 1.A freeze-frame is generated on an OBD-II vehicle _____. a)When a type C or D diagnostic trouble code is set b)When a type A or B diagnostic trouble code is set c)Every other trip d)When the PCM detects a problem with the O2S

25. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 2.An ignition misfire or fuel mixture problem is an example of what type of DTC? a)Type A b)Type B c)Type C d)Type D

26. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 2.An ignition misfire or fuel mixture problem is an example of what type of DTC? a)Type A b)Type B c)Type C d)Type D

27. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 3.The comprehensive component monitor checks components for _____. a)Opens b)Rationality c)Functionality d)All of the above

28. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 3.The comprehensive component monitor checks components for _____. a)Opens b)Rationality c)Functionality d)All of the above

29. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 4.OBD II has been on all passenger vehicles in the United States since _____. a)1986 b)1991 c)1996 d)2000

30. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 4.OBD II has been on all passenger vehicles in the United States since _____. a)1986 b)1991 c)1996 d)2000

31. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 5.Fuel trim and misfires are continuosly monitored. a)True b)False

32. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 5.Fuel trim and misfires are continuosly monitored. a)True b)False

33. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 6.DTC P0302 is a _____. a)Generic DTC b)Vehicle manufacturer-specific DTC c)Idle speed-related DTC d)Transmission/transaxle-related DTC

34. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 6.DTC P0302 is a _____. a)Generic DTC b)Vehicle manufacturer-specific DTC c)Idle speed-related DTC d)Transmission/transaxle-related DTC

35. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 7.The MIL is turned off if _____. a)The codes are cleared with a scan tool b)Power to the PCM is disconnected c)The vehicle is driven on three consecutive trips with a warm-up cycle and meets all code set conditions without the PCM detecting any faults d)Any of the above occur

36. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 7.The MIL is turned off if _____. a)The codes are cleared with a scan tool b)Power to the PCM is disconnected c)The vehicle is driven on three consecutive trips with a warm-up cycle and meets all code set conditions without the PCM detecting any faults d)Any of the above occur

37. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 8.Which generic DTC could indicate that the gas cap is loose or a defective emission control system? a)P0221 b)P1301 c)P0442 d)P1603

38. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 8.Which generic DTC could indicate that the gas cap is loose or a defective emission control system? a)P0221 b)P1301 c)P0442 d)P1603

39. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 9.The computer will automatically clear a DTC if there are no additional detected faults after _____. a)Forty consecutive warm-up cycles b)Eighty warm-up cycles c)Two consecutive trips d)Four key-on/key-off cycles

40. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 9.The computer will automatically clear a DTC if there are no additional detected faults after _____. a)Forty consecutive warm-up cycles b)Eighty warm-up cycles c)Two consecutive trips d)Four key-on/key-off cycles

41. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 10.A pending code is set when a fault is detected on _____. a)A one-trip fault item b)The first fault of a two-trip failure c)The catalytic converter efficiency d)Thermostat problem (too long to closed-loop status)

42. Automotive Fuel and Emissions Control Systems, 2/e By James D. Halderman and Jim Linder © 2009 Pearson Higher Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 CHAPTER QUIZ 10.A pending code is set when a fault is detected on _____. a)A one-trip fault item b)The first fault of a two-trip failure c)The catalytic converter efficiency d)Thermostat problem (too long to closed-loop status)