# APPENDIX C

NEW YORK CITY TAXI & LIMOUSINE

TRAINING PRESENTATIONS

# Introduction To OBD II Introduction To OBD II

George E. Pataki Raymond P. Martinez Erin M. Crotty

Governor DMV Commissioner DEC Commissioner



# Introduction

Onboard Diagnostics, OBD , technology
benefits motorists, technicians and the environment by monitoring a vehicles

performance every time it is driven, identifying performance and emissions

problems immediately and providing technicians with information to help them quickly and accurately diagnose and repair malfunctions

# Early OBD Systems (Pre – 1996)

 

# The first OBD systems appeared on vehicles in the 1980’s (OBD I) and mon itored fuel, ignition and emissions systems components.

 

# When a fault was found a code was stored in the vehicles onboard computer and in many instances a “Check Engine” light was lit to

alert the driver.

 

# Technicians could connect to the computer

and see what codes had been set and make a diagnosis of the problem



# Early OBD Systems (Pre – 1996)

(Continued)



# While the concept was a good one, several practical problems were found in actual use.....

 

# No Standardization of da ta link connectors – a

different one needed for each manufacturers vehicles

 

# Trouble codes not consistent between manufacturers

 

# No standardization of emissions control device and system names between manufacturers

 

# Criteria to light check en gine light not consistent

between manufacturers

 

# Type of stored information in vehicles computer

varied from manufacturer to manufacturer

# OBD II Systems

Noting that OBD systems were valuable technology in

maintaining good performanc e and lower emissions in

vehicles, the U.S. EPA developed regulations that

required all vehicles meet specific and consistent standards for OBD systems, OBD II , by 1996

These regulations resulted in standardization of,

 

# Data Link Connector an d location in vehicle

 

# Terminology for vehicle emissions control components

 

# Diagnostic trouble codes

 

# Freeze Frame – storage of engine conditions at time a

DTC is set

 

# Requirements for lighting MIL (Check Engine Light)

 

# Determination and recording of readiness status of system monitors



# DLC

Standardized Data Link Connector

 

# Allows generic scan tool to be used on all
OBD II equipped systems.

 

# Contains 16 terminals – some OBD II

dedicated and some manufacturer
discretionary.

 

# Location of DLC standardized.

# Standardized Terminology

 

# Different manufacturers used different names / acronyms for essentially the same

components / systems.

 

# The Society of Automotive Engineers, S.A.E., developed standardized terminology for engine and emissions systems.

 

# See Glossary in Inspectors Reference Guide for examples.



# OBD Failure Criteria

 Reasons for failing an OBD II inspection

 MIL does not light with key on – engine off (KOEO)

 MIL is lit with the key on - engine running (KOER)

 Scan tool indicates DTC’s, and MIL is commanded on by the PCM, even if it is not lit

 More than the allowable number of monitors are found to be “not ready”

 DLC is missing or damaged – communications

failure

# MIL
Malfunction Indicator Light

 The MIL is a light on the dashboard to alert the driver of an emissions related problem. The MIL will be lit if one of the following conditions is
present,

 Severe misfire which could cause catalytic converter damage will cause it to flash on and off.

 A steadily lit MIL indicates a DTC has been set.



#  The OBD II system can turn the MIL off on it’s own if it detects that the cause of the MIL being lit

has been corrected.



# DTCs
Diagnostic Trouble Codes

 

# Prior to OBD II each manufacturer had it’s

own list of trouble codes.

 

# Under OBD II all manufacturers must use a

universal 5 digit code system.

# DTC’s Diagnostic Trouble Codes (Continued)



#  

# There are two types of DTC’s, 1 trip DTC’s and 2 trip DTC’s

 

# A 1 trip DTC is for a co ndition that requires
immediate attention such as a catalyst damaging

misfire.

 

# A 2 Trip DTC is one that a condition must be found
during 2 consecutive trip s such as an EGR fault.

 

# Most Monitors do not set a DTC and light the MIL
when a vehicle fails a test for the first time during a

DRIVE CYCLE. If a test is failed on a second
consecutive DRIVE CYCLE the MIL will light and a
DTC is stored in the vehicles powertrain control
module (PCM).



# System Monitors

& Readiness Status

 

# One of the features of OBD II testing is that thevehicle need not be warmed up or preconditioned before doing the test.

 

# The OBD system periodically runs what are called

MONITORS to determine if the various emissions control devices and systems are READY and able to operate as they were designed.

 

# Some Monitors are CONTINUOUS monitors and

some are NON-CONTINUOUS monitors.

 

# Monitors are run during what are called

DRIVE CYCLES

# Continuous & Non-Continuous

Monitors

 

# Some vehicle components are

continuously tested by OBD II while
others are only tested under certain
operating conditions.

Continuous Monitors Continuous Monitors

• Misfire

• Fuel System

• Comprehensive Components Non

- Continuous Monitors Continuous Monitors

• EGR System

• O2 Sensors

• Catalyst

• Evaporative System

• Others (if vehi cle equipped) –

Secondary Air, H eated Catalyst, A/C System



# System Monitors

& Readiness Status

(Continued)

 

# If a Monitor is run completely and the system / component being tested operates properly, the monitor is recorded in the powertrain control module (PCM) as ready, complete or done.

 

# Disconnecting the vehicles battery or clearing stored DTCs from the PCM will usually reset the

monitor readiness status to NOT READY

 

# 1996 – 2000 model year vehicles FAIL if more than 2 monitors are “Not Ready”.

 

# 2001 and Newer model year vehicles FAIL if more than 1 monitor is “Not Ready”.

# Drive Cycles

 

# What constitutes a DRIVE CYCLE can vary

from monitor to monitor and across all

makes and models.



# Freeze Frame

 

# Whenever an emissions related malfunction occurs, OBD II stores the operating parameters (conditions) present at the time

the malfunction occurs.

 

# Parameters recorded ar e, but are not limited

to:

• Fuel Pressure

• Fuel Trim Value ( Rich or Lean )

• Engine Coolant Temperature

• Intake Manifold Pressure

• Open or Closed Loop Status

• This data is valuable to assist technicians in diagnosing the

cause of the malfunction. • DTC Description

• Engine Speed

• Vehicle Speed

• Air Flow

• Engine Load

# System Reports

The TLC equipment will continue to produce reports as in the past.

Rejection Notices for vehi cles failing an OBD II inspection will contain the following added
information,

 

# Status of communication with PCM

 

# Listing of DTC’s found stored

 

# Number of monitors found “Not Ready”

 

# MIL status check1Ford Crown VictoriaFord Crown Victoria&OBD/IM ReadinessOBD/IM Readiness2ContentsContentsIntroduction To OBDReview Of OBD MonitorsP1000 Code & IM ReadinessOBD Emission InspectionOBD Resources3What Is OBD?What Is OBD?Real-time, on-board monitoring system that isembedded in the Powertrain Control Module (PCM).Monitors all emission related components andsystems as mandated by government agencies likeEPA and CARB.Fault is communicated to the customer by means ofthe “Check Engine” light, also known as theMalfunction Indicator Light (MIL), along with aDiagnostic Trouble Code (DTC) set in the PCM.4Brief History Of OBDBrief History Of OBDOBD-I was implementedfor 1988 and latermodel year vehicles.Monitoring limited to –Oxygen SensorEGR SystemFuel SystemInput ComponentsMIL illuminated onlywhile the fault ispresent.OBD-II was implemented acrossall vehicle lines in 1996 modelyear vehicles.Monitoring extended to include –Oxygen Sensor (enhanced)EGR System (enhanced)Fuel System (enhanced)Input/Output Components (CCM)Catalyst EfficiencyMisfireEvaporative SystemSecondary Air SystemMIL is illuminated and remains onuntil there are 3 consecutive tripswithout the fault being present.5OBD MonitorsOBD MonitorsMisfireExhaust Gas Re-circulation (EGR)EVAPHeated Exhaust Gas Oxygen Sensor (HEGO)Catalyst EfficiencyFuelSecondary AirComprehensive Component Monitoring (CCM)6What Turns On The MIL?What Turns On The MIL?Front HEGORear HEGOHEGO HeatersProcessorWiring harnessHEGOVacuum linesFuel InjectionAir inlet systemFuel pumpThermostatPositive CrankVentIntake ManifoldThrottle BodyExhaust ManifoldExhaust PipesExhaust Mufflers-ResonatorsFuel LinesMass AirFlow SensorWiring harnessIdle Air ControlProcessorFuel pressure reg.FuelBase engineProcessorFuel InjectorSpark PlugSpark PlugWireIgnition CoilIgnition CoilWireEDISCrank PositionSensorCrank PositionWheelDamperIgnition DiagnosticMonitorFuel Pressure RegulatorWiring harnessOil qualityFuel QualityMisfireEGR ValveEGR HosesElectronic VacuumRegulationDelta PressureFeedback Sens.EGR Valve Pos.SensorWiring harnessEGR TubeManuf. or exhaustgas debrisVacuum linesReservoirEGRAir PumpAir Control ValveVacuum SolenoidWiring harnessVacuum linesSec. AirCatalystFront HEGORear HEGOProcessor PinsWiring harnessCatalystVapor MgmntValveCanister VentSolenoidGas CapVapor CanisterFuel Tank Press.TransducerVapor HosesWiring harnessVacuum linesFuel pumpEvapDistribution sys.Relays, battery,electricalVacuum linesIgnition CoilWiring harnessFuel Temp.Flex Fuel SensorTransmissionRange SensorShift SolenoidTurbine ShaftSpeed SensorElectronic PressureSolenoidOutput ShaftSpeed SensorAir ChargeTemp.Cooling FanThermostatKnock SensorIntake ManifoldCommunicationControlFuel PumpEngine CoolantTemp.Brake OutputSensorVehicle SpeedSensorThrottle PositionSensorIntake ManifoldRunner ControlIdle Air ControlOctane Adj.Barometric PressureSensorCamshaft PositionSensorMass Air FlowSensorIntake ManifoldRunner ControlVariable CamTimingFuel InjectorsManifold AbsolutePressure SensorCCMMIL ON7Fault FilteringFault FilteringTypically, circuit fault have to be present for 5consecutive seconds before a DTC is stored.DTC is stored if fault is detected.MIL is illuminated only if fault is present for 2consecutive drive cycles.The MIL is turned off after 3 consecutive tripswithout the fault being present.The DTC is erased from memory after 40 warm-upswithout the fault being present.8P1000 Code & IM ReadinessP1000 Code & IM Readiness"P1000" code. Don’t look at a P1000 code as a fault code."P1000" code. Don’t look at a P1000 code as a fault code.I/M programs look ata set of I/M Readiness flags that tell which OBD monitors avehicle has, and which havebeen run since codes were lastcleared (or battery disconnected).EPA's OBD Technical Guidance, applicable to testing of 1996 and later Model Year lightduty vehicles (<8500 lbs. GVWR) allows:9no more than two unset readiness monitors for 1996 through 2000 Model Yearvehicles9and no more than one unset readinessmonitor for 2001 and newer Model Yearvehicles.9Note that the Guidance is not applicableto vehicles which exceed 8500 lbs GVWR.States are, however, allowed to conductsuch testing, but readiness criteria foreither rejection from testing or pass/fail determination may vary among states.Not all monitors need to be run inorder to get through an I/M test. When youeliminate the P1000, it means all monitorshave been run, even though the EPArequirement could have allowed up totwo monitors to be not ready.*To run all the monitors when it isnot necessary, is a waste of time andresources.9How Do I Pass The OBDII Emission Inspection?How Do I Pass The OBDII Emission Inspection?Essentially, five things must be satisfied to pass the inspection:1. The emissions MIL must illuminatewith the key on and engine off;2. The emissions MIL must be commanded off by the OBD II system, and:3. Required readiness monitors must be completed.4. No MIL with the key on engine running (KOER)5. Must have communication*You can easily verify that you will pass the 1stcriteria by confirming that the MIL bulb lightsup when the key is turned tothe engine on position (but not started). You can then startthe engine and see if the MIL stays on. If it is on,you will fail the 2ndcriteria, so yourvehicle must be repaired before you can pass the test.10My Taxi Didn’t PassMy Taxi Didn’t PassNow What Do I do?It depends on why it didn’t pass.If the emissions MIL is on, the OBD II system has found aproblem that needs to be fixed.If the MIL won’t light, then the bulb and/or circuitry must berepaired.If the required readiness monitorsare not set, then additionaldriving is required.*There are many reasons the monitors could be set to “not ready”. Usuallythis is caused by routine maintenance. For instance, if the battery isdisconnected for any reason, the monitorsof most vehicle are reset. Also, aservice technician may have to resetthem as part of a repair process.* Essentially, the car must be drivento reset the monitors. See handout for“Drive Cycle Recommendations”.11OBD ResourcesOBD ResourcesCalifornia Air Regulatory Board (CARB) OBDweb site –arbis.arb.ca.gov/msprog/obdprog/obdprog.htmEnvironmental Protection Agency web site –www.epa.gov/OMSWWW/obd.htm12OBD ResourcesOBD Resourceswww.motorcraftmotorcraft.com