OBDII Readiness Case Study

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OBDII Readiness Case Study Powered By Docstoc
					VOLUME 8 s NUMBER 2
APRIL 2005

                      OBDII Readiness Case Study
                         by Angelo Vitullo, Emissions Program Instructor, Automotive Technology Department;
                                           St. Louis Community College, Forest Park Campus
                                                                                          By researching the “enabling

         he owner of a 1998              Once I got involved at Outreach’s
         Chrysler Cirrus, with a       request, I contacted the repair facility         criteria” necessary to run monitors for
         2.5L engine and A/T,          and the customer directly to get the             the EGR, HOS2 and CAT monitors, I
  SMPFI, and odometer at               information I needed to repair the               found they all require a minimum
  91,000 miles informed a service      vehicle. Using my scan tool to check             ambient temperature of 19 degrees F.
  manager of an OBDII                  the OBDII system, the only monitor                 Also, the OBDII Misfire Counter
  emissions test reject because of     that was complete was the HO2S                   was not functioning. This vehicle, as
  monitors. The inspection             monitor. This monitor is enabled at              with most others, must “learn” the
  reports showed the service           idle after a cold start with engine              specific electrical characteristics of the
  manager that the vehicle had         temperature below 127 degrees F and              crank sensor, the crank sensor air gap,
  been rejected at the test station    battery temperature within +/-27                 the machining characteristics of the
  seven times over a five-month        degrees of engine temperature. I                 crankshaft tone wheel, and so on.
  period. Setting monitors             wondered why that monitor ran and                Chrysler calls this learning process the
  during normal driving wasn’t         no others did?                                   Adaptive Numerator. There is a drive
  an issue since a cross-country                                                        cycle consisting of a series of vehicle
  trip was taken during that five-                                                      decelerations required to perform this
  month period. The repair                OBDII MON                                     learning process for this particular
  facility scan tools also                DISABLED STATUS                               vehicle. Some brands of vehicles can
  confirmed the test station                                                            perform this learn function in the
                                          OBDII MON DISABLED LoTemp: YES                shop bay. Only research will reveal the
  monitor status report. Many
  unsuccessful things were tried,         OBDII MON DISABLED LoBatt: NO                 proper procedure for the subject
  including the installation of a         OBDII MON DISABLED LoBaro: NO                 vehicle in your shop. Without
  remanufactured PCM, and the                                                           Guidance, We Are Lost. The scan tool
  technician driving the vehicle                                                        readout stated the vehicle did not
  according to drive trace               When eyeballing long lists of live             complete the Adaptive Learn
  procedures also accomplished         sensor data, it is easy to overlook key          procedure, hence the misfire counter, a
  nothing. Finally the vehicle was     pieces of information while trying to            continuous component monitor
  returned with instructions to        rationalize every value displayed. But I         (CCM) was disabled. In researching
  “drive the car for a few days.”      did notice the Ambient/Battery                   the enabling criteria for the Misfire
  The customer departed more           Temperature Sensor was sending an                Monitor, I learned it also would be
  frustrated than ever.                erroneous very cold signal of -7.6               disabled due to the ambient
                                       degrees F. On a 70 degree F day, this            temperature requirement of 19
                                       was a red flag.                                  degrees.
   CONTENTS                                                                               While researching the wiring
                                                                                        diagrams and component locations
  s OBDII Readiness Case Study            SENSORS                                       guide, I saw there was a temperature
                                                                                        measurement thermistor located
  s Transmission Codes                    CURRENT ADAP CELL ID: O
                                                                                        behind the left headlamp housing. It
  s 2005 Outreach Seminars                ENG COOLANT TEMP DEG: 73.4F
                                          ENG COOLANT TEMP VOLT: 2.59V
                                                                                        was a three- wire sensor called the
  s Setting Monitors That Defy                                                          Battery Temperature Sensor. The
    Standard Methods                      INTAKE AIR TEMP DEG: 68.0F
                                                                                        calibration error had suspended the
  s Another Way to Explain                                                              running of all monitors except the
    Monitors to your Customers
                                                                                                     continued on page 2
                         Transmission Codes
                                 by Michael Hills, Engineer, Technical Services;
                                Division of Mobile Source Programs, Illinois EPA

   f the MIL is commanded on for a transmission code, it is emissions related. OBDII is required to

I  monitor all powertrain components that effect emissions, or provide diagnostic input, or receive
   commands from the PCM. The transmission controls the amount of power going from the engine to
the wheels. If the transmission is not working properly, the efficiency of the power transfer will be
degraded. Simply stated, the engine of a vehicle with a malfunctioning transmission will have to work
harder to provide the same amount of vehicle speed. A harder working engine will require more fuel
which will result in higher emissions. If the sensors that monitor the transmission are not functioning
properly, the PCM cannot determine if the transmission is working properly, resulting in a “Command
On” status, illuminating the MIL. The decision to include these sensors is made by the manufacturers.
  Transmission codes can also indicate problems with engine misfire. Most vehicles detect misfire using a
crankshaft position sensor to detect even a minute fluctuation in crankshaft acceleration and rotation.
Shifting on rough roads can cause false readings. Therefore, some manufacturers unlock the torque-
converter clutch when strong road vibration is detected. If the transmission is not functioning properly,
the unlocking of the torque-converter might be triggered prematurely, resulting in an engine misfire that
could go undetected.

 continued from cover
 HO2S Heater Monitor. Why? Because that                    resulting MIL Lamp Illumination. The vehicle
 monitor will run as long as there is a cold start         ran all the monitors and passed. The customer
 and battery temperature is within +/- 27                  was ecstatic that the problem was fixed.
 degrees of engine temperature. In other words
 if the engine coolant temperature is 18 degrees           Lessons Learned
 or less during a cold start the HO2S Heater                 OBDII is very reliable and things happen for
 Monitor will run. Knowing a prior repair shop             a reason. Diagnostics must be performed,
 replaced the PCM in vain, I double checked the
                                                           prioritized and carried out with precision.
 part number to confirm it was correct.
                                                           Access to vehicle data is an absolute
    I was confident the problem was the
                                                           requirement. Without Guidance, We are Lost.
 Ambient/Battery Temperature Sensor. After a
                                                           Although the purpose of OBDII system designs
 wiring check I replaced the sensor and, using
                                                           are to standardize connectors, component
 the scan tool, recorded a realistic temperature
                                                           names, DTCs, etc., actual monitor routines,
 value. The software engineers did not program
                                                           enabling     criteria    and    software-based
 this sensor for rationality code setting
                                                           calibrations are constantly changing, and
 capability. The next goal was to run all the
                                                           nothing can be taken for granted. One must
 diagnostic monitors (OBDII Drive Cycle) to
                                                           approach OBDII challenges with an open mind
 confirm there will be no system failures and
                                                           and be willing to do research.

                                          AIR                    APRIL
                                         REPAIR        2          2005
          FR EE!                        2005 Outreach
                CO M P UTE R                                                         IM240 & OBDI I EM ISSION
           R E-P RO G R AM M I N G                                                     REPAI R DIAGNOSTIC
     College of Lake County                          March 22 (Tues)                  Oakton Community College                         March 24 (Thurs)
     Moraine Valley Comm. College                    March 29 (Tues)                  Morton College                                   March 31 (Thurs)
     Collinsville                                    April 18 (Mon)                   Collinsville                                      April 19 (Tues)
     One-night seminar devoted to the introduction of computer flashing.              One-night seminar devoted to helping technicians that have
     This seminar will help both shop owners and technicians understand               previously attended the various seminars and have been using
     this growing service area. Topics will include the need to program               techniques from those seminars to repair emission failures. Real
     modules, what modules can be programmed, and case studies                        examples will be used to understand both IM240 & OBDII
     on how the many different manufacturers apply this             !                 emission failures with an emphasis on fuel control,                !
                                                                  EW                                                                                   EW
     technology. Discussions will include independent shop                            catalytic converter function, OBDII code and readiness
     applications, and there will be demonstrations of                                concerns.
     reflash procedures.
                                                                 N                                                                                    N
    Air Repair is published by Envirotest Illinois, Inc.               U S I N G A D I G ITAL STO R AG E
       Send all address changes, mailing requests
               and letters to the editor to:                                 OSC I LLOSCO P E F O R
                        Air Repair
                 Envirotest Illinois, Inc.                                  E M I SS I O N FAI LU R ES
         130 E. Hill Street • Villa Park, IL 60181
              E-mail: AR@il.etest.com                                  Oakton Community College                           April 11 (Mon)
    phone: (630) 993-6250 • fax: (630) 993-6205                        Prairie State College                              June 6 (Mon)
                 Jim Woodard, Editor
                 Ken Beauvais, Editor                                  One-night seminar devoted to the introduction to using a DSO. Item includes
             Jim Wellman, Technical Editor                             setting up, capturing & interpreting patterns, using multitrace capability, current
                  www.epa.state.il.us                                  probes, vacuum testing and using a vacuum transducer. Strongly recommend
      Repair Industry Outreach • (847) 758-3434                        before attending IM240 and OBD seminars.

                                H OW TO F IX AN I M240 FAI LU R E
                                                         PART 1                              PART 2                                 PART 3
     Oakton Community College                        April 25 (Mon)                       May 9 (Mon)                            May 23 (Mon)
     Prairie State College                           August 1 (Mon)                      August 15 (Mon)                        August 29 (Mon)
                                    A must for all technicians diagnosing & repairing IM240 failures.
                s A functioning oxygen sensor s Fuel control w/ no misfires s 80 percent efficient catalytic converter
     Proven methods, techniques & proper testing of oxygen sensor & fuel control, lean & rich settings, the relationship of fuel trim to emissions testing
     and how to determine when a vehicle has been properly repaired is discussed, along w/ fuel injection and testing, using digital storage oscilloscopes
     & current probes. Also covered is compression & ignition problems, different methods of testing catalytic converters, and what causes hydrocarbon
     & carbon monoxide failures. Strongly recommend attending the DSO seminar before attending this seminar.

                                                                         All Seminars are from 6-10 pm, are
                                                                         sponsored by the Illinois EPA and
    IS REQUIRED!                                                         Envirotest Illinois for the repair
Call: (847) 758-3434                                                     industry and are FREE!
                                                               AIR                          APRIL
                                                              REPAIR           3             2005
Seminars                                                                              FREE!
                                 H OW TO F IX AN O B D I I FAI LU R E
                           PART 1          PART 2                               PART 1        PART 2
Truman College          April 13 (Wed) April 14 (Thurs) Prairie State College May 25 (Wed) May 26 (Thurs)
McHenry County College April 27 (Wed) April 28 (Thurs) Oakton Comm. College June 8 (Wed) June 9 (Thurs)
Waubonsee Comm. College May 11 (Wed) May 12 (Thurs)
Two-night seminar devoted to the introduction & overview of the OBDII system, readiness monitors, DTC types & conditions, drive cycles and using freeze frame
data & fuel trim diagnosis. Also covers diagnosis & repair of oxygen sensor, EGR, & EVAP systems. Misfire detection & catalytic converter monitors also are discussed
(repeat from 2004 w/ enhancements & updates). FREE Readiness Drive Trace CD for those that attend.

  SHOP MANAGEMENT FOR                                                                     HOW TO DIAGNOSE &
    EMISSIONS SUCCESS                                                                  REPAIR OBDII PO300 CODES
Elgin Community College          June 20 (Mon)                                         College of DuPage             October 25 (Tues)
McHenry County College           June 21 (Tues)                                        Moraine Valley Comm. College October 27 (Thurs)
Moraine Valley Comm. College    June 23 (Thurs)                                        McHenry County College       December 12 (Mon)
Oakton Community College     September 12 (Mon)                                        Triton College               December 14 (Wed)
Collinsville                 September 15 (Thurs)                                      One-night seminar devoted to understanding the misfire detection
Triton College                 October 24 (Mon)                                        monitor, using the oxygen sensor, fuel trim & scanner data as a baseline
                                                                                       for misfire repair. Using the DSO to monitor compression, ignition &
Prairie State College        November 28 (Mon)                                         fuel also is discussed (repeat from 2004).
One-night seminar devoted to everyone behind the counter that comes
in contact w/ customers. Shop Owners, Service Managers & Service
Writers are given helpful suggestions on managing/taking control of

         R E PAI R TEC H N I Q U ES:                                                                L O C AT I O N S
                                                                                                           NORTH                                  WEST
Collinsville                                          September 14 (Wed)                            College of Lake County                Elgin Community College
Truman College                                         October 11 (Tues)                                  (Grayslake)                              (Elgin)

Joliet Junior College                                  October 13 (Thurs)                         Oakton Community College                   College of DuPage
                                                                                                         (Des Plaines)                           (Glen Ellyn)
Oakton Community College                               November 7 (Mon)                            McHenry County College             Waubonsee Community College
College of Lake County                                 November 8 (Tues)                               (Crystal Lake)                        (Sugar Grove)
Moraine Valley Comm. College                          November 29 (Tues)                                    SOUTH                                  EAST
College of DuPage                                     December 1 (Thurs)                      Moraine Valley Community College                 Morton College
Morton College                                        December 15 (Thurs)                                (Palos Hills)                            (Cicero)
                                                                                                       Joliet Junior College                    Triton College
One-night seminar devoted to two separate topics. The first topic covers
                                                                                                               (Joliet)                          (River Grove)
enhanced EVAP systems and their design, function, diagnosis and repair.
Real examples will be used to learn about frequent DTCs and how to                                     Prairie State College                   Truman College
diagnose and repair those problems. The second topic covers the use                                      (Chicago Heights)                        (Chicago)
of MODE 6 as a diagnostic aid. Although not all scanners or                   !
automotive manufactures support MODE 6, there are times                                                                   METRO EAST
when its data is valuable in the diagnosis and/or verification                                                     State of Illinois Regional Complex
of a repair. Using data as a baseline also will be discussed.              N                                                    (Collinsville)

                                                                 AIR                           APRIL
                                                                REPAIR            4             2005
                                         Setting Monitors That
                                         Defy Standard Methods            By Jim Wellman,
                                                                  Envirotest Repair Industry Liaison

                                          hen it comes to setting some of the more difficult to set monitors, learn to
                                          think outside the box.

                                 One example: The vehicle calls for an eight-hour cold soak and an ambient
                               temperature of 32 degrees. What do you do when its 20 degrees outside? One
                               solution might be parking the vehicle inside overnight before driving the trace
                               requirements. Another way might be to figure out where the computer is getting the
                               temperature reading from, (i.e. coolant temperature sensor, battery temperature
                               sensor, intake air temperature sensor, etc.) and use a sensor substitution device to
                               fool the computer into thinking that it is warmer than it really is.
  Another example: If the condition necessary to run a monitor calls for an ambient temperature above a certain
temperature and the computer is looking at the intake air temperature, take the sensor out and lay it on the
cylinder head so it will get warm enough to meet the temperature requirements. Plug the hole in the manifold and
run the trace necessary to set the monitor (a trick from Ralph Koos, Mercedes-Benz Technical Specialist).
  These are just a couple of examples of doing what it takes to get a monitor to set. Take the time to learn what is
necessary to run the monitor and what input the computer needs. It won’t always be easy, but thinking outside the
box could help you set monitors that present unusual challenges.

                    Another Way to Explain Monitors to Your Customers
        Monitors are like the anti-virus software in your personal computer. Anti-virus software scans your computer to
        find problems and then alerts you to what it finds. Monitors do the same; they check to see if different
        components and systems are working properly. If a problem is found, a diagnostic trouble code is set and the
        malfunction indicator light (check engine light) is illuminated. For these checks to run, certain enabling
        conditions and criteria are necessary, which vary from monitor to monitor and manufacturer to manufacturer.

                       CALL REPAI R I NDUSTRY OUTREACH
                        IF YOU HAVE QU ESTIONS ABOUT:
                    s Free Seminars                            s Obtaining a copy of  your shop’s Repair
                    s Fixing IM240 or OBDII Failures
                                                                 Effectiveness Report (your grade)
                                                               s Receiving a copy of a drive trace
                    s Repair Facility Performance Report
                                                               s Receiving a certificate for attending an
                    s Touring a Test Station
                                                                 Outreach Seminar
                                         ...or ANY emissions related questions!

                                               (847) 758-3434
                               or visit our website at www.epa.state.il.us

                                                 AIR                      APRIL
                                                REPAIR        5            2005
Air Repair                                                                           Presorted First Class
Envirotest Illinois, Inc.                                                                US Postage
130 E. Hill Street                                                                       Permit #112
Villa Park, IL 60181                                                                   Carol Stream, IL

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Call us at: (847) 758-3434                           Or mail to: Illinois Environmental Protection Agency
                                                                   Vehicle Emissions Test Program
Email: AR@il.etest.com                                             PO Box 767
                                                                   Elk Grove Village, IL 60009-0767

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                                                 AIR                  APRIL
                                                REPAIR      6         2005