1 / 20

CHAPTER 51

CHAPTER 51. Emission Control. Using a Five-Gas Analyzer. 51-1. Research the local emission limits for this vehicle in the applicable manual or online sources. Warm up both the vehicle and the exhaust gas analyzer. Leak test the analyzer hose and probe. Using a Five-Gas Analyzer. 51-1.

adolph
Download Presentation

CHAPTER 51

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHAPTER 51 Emission Control

  2. Using a Five-Gas Analyzer 51-1 • Research the local emission limits for this vehicle in the applicable manual or online sources. Warm up both the vehicle and the exhaust gas analyzer. Leak test the analyzer hose and probe.

  3. Using a Five-Gas Analyzer 51-1 • Calibrate the analyzer, if applicable. Insert the exhaust analyzer probe in the vehicle's exhaust pipe at least 18" (46 cm).

  4. Using a Five-Gas Analyzer 51-1 • Allow the vehicle to idle and record the emission readings. Compare your readings to the specifications and determine any necessary action(s).

  5. Testing a Catalytic Converter for Efficiency (Lab Scope Method) 51-2 • First, ensure the vehicle is fully warm by performing a road test. After the road test, install a scan tool with graphing capability, and highlight the pre-cat O2 sensor (the sensor in front of the converter labeled sensor 1) and the post-cat O2 sensor (the sensor after the converter, which detects if the gases are converted, labeled sensor 2). • The cat O2 sensors should be labeled, for example, HO2B1S1 (for heated oxygen sensor, bank one, sensor one) and HO2B1S2 (for heated oxygen sensor, bank one, sensor two). If the engine is a four cylinder in-line engine, there is only one bank. Raise engine rpm to 2000 and watch the oxygen sensor readings.

  6. Testing a Catalytic Converter for Efficiency (Lab Scope Method) 51-2 • Set the scan tool so it will graph both sensor readings. The front oxygen sensor will toggle from rich to lean, and the rear sensor (behind the converter) will tend to run at a steady midpoint reading because the converter is using much of the oxygen converting the hydrocarbons and carbon monoxide. If the rear oxygen sensor pattern tracks the front sensor, the catalytic converter is not functioning and will need to be replaced.

  7. Testing a Catalytic Converter for Efficiency (Lab Scope Method) 51-2 • If the front sensor is not toggling properly, the engine or fuel system is not operating properly, and you will need to diagnose that condition further. You need to keep in mind the symptom-to-system to- component-to-cause diagnostic process used by most manufacturers. If the catalytic converter failed, determine the cause of the failure. Replacement of the converter may mask the symptoms but only for a short time, and then they will show up again.

  8. Inspecting and Servicing the PCV System 51-3 • Locate the PCV valve. With the engine idling, remove the PCV valve and check for the presence of a strong vacuum.

  9. Inspecting and Servicing the PCV System 51-3 • Remove the hose and check that it is still pliable and not clogged with sludge deposits.

  10. Inspecting and Servicing the PCV System 51-3 • Remove the PCV valve and inspect it for deposits. If it is restricted, is sludged up, or sticks, replace it with a new one of the same type.

  11. Inspecting and Servicing the PCV System 51-3 • Reinstall the PCV valve into the valve cover, and remove the breather hose from the air cleaner assembly.

  12. Inspecting and Servicing the PCV System 51-3 • With the engine idling, block off the breather hose and feel for vacuum building up in the breather hose and crankcase, indicating that the PCV system can handle the amount of blow-by gases.

  13. Testing the EGR System 51-4 • Determine the type of EGR valve the vehicle is equipped with and the test procedure needed. Assuming you are working with a digital EGR valve, follow the procedures in the service information. • Attach a scan tool to the data link connector (DLC) and retrieve any codes related to the EGR system. If diagnostic codes are present, follow the trouble chart in the service information for further diagnosis. • Follow the manufacturer's troubleshooting chart. If the troubleshooting chart tells you to inspect passageways, it may be necessary to remove the EGR valve to inspect.

  14. Testing the EGR System 51-4 • Based on the diagnostic chart, determine the path to follow to repair the vehicle. • Verify the repair. Drive the vehicle to ensure that the repair was performed properly before releasing the vehicle to the customer.

  15. Testing the EGR Sensors 51-5 • Research the procedure for testing the electrical sensors and wiring of the EGR sensor system in the service information. • Attach a scan tool to the DLC and retrieve any codes related to the EGR sensor. If diagnostic codes are present, follow the trouble chart in the service information for further diagnosis.

  16. Testing the EGR Sensors Follow the service information procedure for testing the EGR sensor and wiring. Testing will involve the use of a digital volt-ohmmeter (DVOM) and basic electrical testing. It may also require a scan tool to activate the EGR valve for testing purposes. Follow the service information for testing. After following service procedures, determine any necessary actions. 51-5

  17. Inspecting the Secondary Air Injection System 51-6 • Check for any stored DTCs related to the secondary air injection system with a scan tool. If any are found, research the service information for proper procedures for diagnosing the codes. Ensure you have a proper understanding of the system's operation before attempting to repair the system. • Check the system's operation. Air should be directed toward the exhaust manifold during engine warm-up and to the converter once warm. • Determine necessary actions. If the air pump is locked or any mechanical components are seized, replace with new parts and retest the system.

  18. Inspecting and Servicing the Hoses of the EVAP System 51-7 • Use a scan tool and check for codes related to the EVAP system. If a code is found, follow the diagnostic procedures for that code. If the diagnostic code indicates a leak, connect an EVAP tester to the EVAP test port.

  19. Inspecting and Servicing the Hoses of the EVAP System 51-7 • Use the EVAP system leak detector to determine if the system is in fact leaking and, if so, the size of the leak.

  20. Inspecting and Servicing the Hoses of the EVAP System 51-7 • Use a smoke machine to help locate the leak. If smoke is detected, look in the area of the smoke to identify the cause of the leak. If no smoke is detected, the system could be leaking internally through a stuck-open purge valve or a leaky vent valve. Repair according to the manufacturer's procedure.

More Related