Toyota training 973a hi tech update engine technician handbook 01 08 09

5 Readiness Monitor Test Results ...7 Monitor Information -Key ON, Engine OFF ...8 Monitor Information -Engine Running ...9 Readiness Monitor Test Details ...10 Readiness MonitorTest Det

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Course L973A:Introduction to Advanced Engine Control I

Section 1 1

Accumulated Emissions FTP 2

Emission Levels 3

CAN OBD II Update 4

Interpreting Non-Continuous Readiness Monitor Status and Results 5

Readiness Monitor Test Results 7

Monitor Information -Key ON, Engine OFF 8

Monitor Information -Engine Running 9

Readiness Monitor Test Details 10

Readiness MonitorTest Details -DTCs Cleared 11

Permanent DTC 12

Permanent DTC 13

Permanent DTC -Three Trip Clear 14

Permanent DTC -One Trip Clear 15

Permanent DTC 16

Calculated Load(Calc Load) 17

Vehicle Load -Absolute Load 18

Air Flow 19

MIL ON Data List 20

Section 2 - Misfire 21

Misfire Detection 22

Misfire Data List 23

continued 24

Misfire Margin 25

Cat OT MF/FC 26

Cylinder Misfire Rate (Count) & EWMA Misfire 27

continued 28

Example of EWMA Misfire Count 29

Cylinder Speed Data List 30

Section 3 - Overview of Sensor Operation 31

Circuit Configuration of Mass Air Flow Meter 32

A/F Sensor 33

Current and Voltage Characteristic 34

Table of Contents

Technical Training

A/F Sensor Circuit 35

Comparisons between A/F Sensor and O2 Sensor 36

O2 Sensor Construction 37

CO and O2 Effect on Oxygen Sensor 38

Super Stability O2 Sensor 39

Heater Circuit 40

Heater Operation 41

Temperature Detection 42

A/F Sensor Circuit 43

A/F Ratio Sensor Pumping Circuit 44

O2 Sensor Circuit 45

O2 Sensor Temperature and Impedance 46

Section 4 - Overview of Fuel Injection & Catalytic Converter 47

Stoichiometric Lamda Air/Fuel Ratio 48

Oxygen Storage Capacity (OSC) 49

Oxygen Storage Capacity (OSC) 50

Fuel Injection Duration 51

Fuel Trim 52

Fuel Trim Response 53

Fuel Trim Diagnosis 54

Fuel Trim Parameters and Values 55

Fuel Trim Diagnosis Tips 57

Relationship between Fuel Injection Duration and MAF Malfunction or Air Leak 58

MAF Air Flow Comparison Check w/Load 59

MAF Air Flow Comparison Check wo/Load 60

Airflow-Free VG Check 61

Characteristics of MAF Sensors 62

Relationship between Fuel Injection Duration and Fuel System Malfunction 64

Fuel Trim DTC(s) with Driveability Issues 65

Section 5 - Catalytic Converter & A/F - O2 Sensor Monitors 66

AF Sensor Pumping Circuit 67

AF Sensor Circuit 68

O2 Sensor DTCs by Impedance Detection 69

O2 Sensor Circuit 70

O2 Sensor Temperature and Impedance 71

Active A/F Control Sequence 72

Active AF Type 73

Catalyst Monitor 73

A/F Sensor 74

Active AF Control for AF Sensor Response 75

AF Sensor Response – DTC P2A00, P2A03 76

Active AF Control 77

Active AF Control for O2 Sensor & Catalytic Converter Response 78

Good O2 Sensor Response Rich to Lean 79

Good O2 Sensor Response Lean to Rich 80

Active AF Control Capture – O2 Sensor Response 81

P0136 O2 Sensor Circuit Abnormal Voltage 82

HO2 Sensor Circuit Malfunction 83

P0137 O2 Sensor Circuit Low Voltage 84

P0138 O2 Sensor Circuit High Voltage 85

HO2 Sensor Circuit 86

P0138 Stuck Lean AF Sensor 87

Injector Volume & AF Active Tests 88

P0138 – Malfunctioning AF Sensor 89

P0138 – Check for Malfunctioning AF Sensor 90

CO and O2 Effect on Oxygen Sensor 91

Active AF Control 92

Good Catalyst Response 93

Good Catalyst Response 94

Active AF Control Capture – Good Catalyst Response 95

Deteriorated Catalyst – Active AF Control 96

Active AF Control Capture – Failed Catalyst Response 97

Catalyst Monitoring System 98

Interpreting Catalyst OSC Test Details 99

Conditioning for Sensor Testing 100

A/F Ratio Sensor Rationality Check 101

AF Sensor Stuck Lean P2195 102

Drive Pattern 103

Drive Pattern 104

Inspection 105

Heated Oxygen Sensor Voltage Fuel Cut (DTC P0139 and P0159) .107

Technical Training

Section 6 - EVAP Purge Operation and Monitor 108

The Way Purge Density Is Learned 109

Purge Control 110

EVAP Purge Flow and Purge Density Learn Value 111

Calculation Example of Purge Density Learn Value 112

Engine Running Purge Flow Monitor 113

Knock Control System 114

Knocking Threshold and Fuel Consumption / Engine Output 115

Resonant Knock Sensor 116

Flat Response Knock Sensor 117

Switching of Knock Detection Filter Frequencies 118

Knock Judgment 119

Calculation Example of a Knock Value( renewed every 0.5 seconds approximately) 120

Learning Ranges 121

Relationship Among Timing, Knock Correct Learn Value, and Knock Feedback Value 122

Relationship Among Timing, Knock Correct Learn Value, and Knock Feedback Value 123

Conditions under which a Knocking Problem Occurs 124

Unit of MAF 125

Course 973A:

Introduction to Advanced Engine Control

The technician will be able to determine the condition of advanced CAN OBDII engine control systems based on verified diagnostic repair procedures and technical information using: monitored test results, diagnostic tools, and service literature

Technical Training 1

Section 1

Objectives

CAN OBDII Update

Determine the condition of a vehicle based on readiness monitor

• results, data list parameters, and status of DTCs Clear Permanent DTCs

• Use new data list parameters for MIL ON diagnosis

•

Complete Incomplete Monitor Status Permanent DTC

Calculated load Vehicle Load Atmospheric Pressure

Accumulated Emissions FTP FTP stands for Federal Test Procedure.

Note that emissions are high, particularly NOx, at start up

Technical Training 3

The Federal equivalents are:

Tier 2 Bin 5 = LEV II ULEVTier 2 Bin 3 = LEV II SULEVDTCs are required to set according to the applicable emission standard

NMOG stands for Non-methane Organic Gases

Interpreting Non-Continuous

Readiness Monitor Status

and Results

Monitor ran and passed this trip.

Monitor ran and failed this trip.

Monitor has not finished testing.

Monitor

is not supported.

Monitor

Evaporative System Ready Incomplete Fail

Readiness Monitors

The goal of the OBD II regulation is to provide the vehicle with an on-board diagnostic system capable of continuously monitoring the efficiency of the emission control systems, and to improve diagnosis and repair efficiency when system failures occur

On-board tests are performed by the ECM Two types of on-board test monitoring are supported: continuous and non-continuous These are known as readiness monitors, or simply monitors

If a readiness monitor fails, DTC(s) specific to the failure(s) are set

Interpreting Non-Continuous Readiness Monitors Status and Results

Understanding Readiness Monitors Status and Results will help to duplicate concerns and verify repairs The following is a guide to interpret non-continuous Readiness Monitors Status and Results:

Complete, Pass

If Status 1 (OBD II), Status 2 (CAN OBD II) displays Complete and

Result displays Pass then the monitor completed testing and passed

this trip Check Test Details for all Readiness Monitors to ensure tests are passing well within the Min Limit and Max Limit thresholds (see

Readiness Monitors Test Details topic for more information)

Incomplete, Fail

If Status 1 (OBD II), Status 2 (CAN OBD II) displays Incomplete and

Result displays Fail then the monitor ran and failed this trip An issue

Technical Training 5

continued with the system currently exists and a DTC is present Diagnosis and

repair is necessary

Incomplete, Pass

If Status 1 (OBD II), Status 2 (CAN OBD II) displays Incomplete and

Result displays Pass then the monitor has not completed testing

this trip This is the default setting This may be due to: the enabling conditions were not met, the monitor did not complete operating, or the ECM is withholding judgment Drive the vehicle per the appropriate Readiness Monitor Drive Pattern or perform the system check (if

applicable) to run the monitor Then re-check the Monitor Information

screen

No Result Information

If Result does not display information, the monitor is not supported and

will not run

Each readiness monitor runs a series of tests If one test fails, the monitor fails and a DTC is set specific to the test.

Test Results can be accessed by clicking the magnifying glass icon

in the Details column of the Monitor Information screen The Result column of the Test Results pop-up window will display Pass or Fail,

depending on the result of the test

The Test Description portion of the Test Results window will display a

description of the specific test that is highlighted

Readiness Monitor

Test ResultsReplace

Technical Training 7

Monitor Information -

Key ON, Engine OFF

When the key is first turned ON, and the engine is OFF, the Monitor Status, Monitor Result, Test Result, and Test Details report on what happened the during the last key cycle

This screen capture was taken with key ON, engine OFF after an overnight soak period

When the engine has started and is running, the Monitor Status and Monitor Result will change to Incomplete and Pass The Test Result and Test Details will display the last trip values where the monitor ran When the monitor runs again, the Test Result and Test Details will report the results from the latest trip.

Monitor Information -

Engine Running

Technical Training 9

Test Details displays Min Limit, Max Limit, and Test Value information

from the last trip the monitor ran This information is also provided in

a graphical representation The MIN arrow represents the Min Limit, the MAX arrow represents the Max Limit, and the yellow triangle in the graph represents the Test Value Use the Min Limit, Max Limit, and Test

Value information as indicators of a pass or fail condition as failures

may not be easily seen in the graph

Test Details can be accessed by clicking the magnifying glass icon in

the Details column of the Test Results pop-up window.

Depending on the Status and Result of specific readiness monitors,

Test Details will display information from different trips.

If

• Status 2 is Complete and Result is Pass, Test Details will display

information from this trip

If

• Status 2 is Incomplete and Result is Pass, Test Details will

display information from the last trip the monitor test completed

If an intermittent MIL ON condition exists, a Monitor Test Details Test

Value may be crossing over a limit threshold After a repair attempt has

been made, clear DTCs and run the monitor again If the same Monitor

Test Details Test Value is within the Min and Max Limit thresholds, the

repair was successful

The Test Details graph on non Can OBD II vehicles may appear different from the illustration Always use the Min Limit, Max Limit, and

Test Value as indicators of Test Details.

If the Test Value was outside of the Min Limit or Max Limit before a repair, and is within the Min Limit and Max Limit after a repair, the repair was probably successful

Note

Note Note Readiness Monitor

Test Details

Readiness Monitor

Test Details - DTCs Cleared

If a readiness monitor test has not completed testing since DTC(s)

were cleared, Test Details will display incomplete information Min

Limit, Max Limit, and Test Value will display incomplete values The

graph will be all red with the MIN and MAX arrows and the yellow

triangle aligned along the center line

If the readiness monitor Test Details displays incomplete information,

drive the vehicle per the appropriate Readiness Monitor Drive Pattern

or perform the system check (if applicable) to run the monitor Then,

re-check the Monitor Information screen.

The Test Details graph on older vehicles may appear different from the illustration Always use the Min Limit, Max Limit, and Test Value as indicators of Test Details.

Note

Technical Training 11

continuous and non-continuous monitors fail Permanent DTCs are set

in conjunction with Current and History DTCs

Permanent DTCs can not be cleared using the Clear DTCs function

on the ScanTool Instead, Permanent DTCs are cleared when the ECM monitor completes and passes three consecutive trips, OR

After clearing DTCs, the monitor passes one trip

When cleared by a ScanTool, the MIL is OFF The vehicle must driven

to clear the permanent DTC

Permanent DTCs are trouble codes that are stored in the ECM when continuous and non-continuous monitors fail Permanent DTCs are set in conjunction with Current and History DTCs

Permanent DTCs can not be cleared using the Clear DTCs function on the Scantool

Instead, Permanent DTCs are cleared by two methods.

1) When the ECM monitor completes and passes three consecutive trips

2) After clearing DTCs with a scantool, the monitor passes one trip.

Permanent DTC

Technical Training 13

Permanent DTC - Three Trip Clear

Permanent DTC will clear after three monitored, good trips

Permanent DTC - One Trip Clear

When DTCs are cleared, the MIL is turned off

Look up the confirmation drive pattern and the universal trip drive tern Operate and drive the vehicle accordingly

pat-You must drive after clearing DTCs

Obtaining a normal judgment and performing a universal trip driving pattern can be done in the same driving cycle or in different driving cycles

It is unnecessary to obtain a normal judgment if the DTCs are for fire or the fuel system

mis-Technical Training 15

Calculated Load (Calc Load)

The Calc Load data list is the same in Data List and generic OBD II data list The data list item is designated as PID $04

Characteristics are:

Reaches 1.0 (100%) at any altitude, temperature, or RPM

• Indicates peak available torque (at that RPM)

• Linearly correlated with intake manifold pressure (engine vacuum)

•

As intake manifold pressure increases, the calculated load value increases

Technical Training 17

Characteristics of LOAD_ABS are:

Ranges 0 to approximately 0.95 (95%) for naturally aspirated

• enginesLinearly correlated with engine indicated and brake torque

• Peak value of LOAD_ABS correlates with volumetric efficiency at

• WOT

Vehicle Load - Absolute Load

Air flow correlates with horsepower: more air flow equals more horsepower

Multiplying 1.32 times MAF g/sec will provide the approximate horsepower the engine is producing This can be useful when talking to customers about fuel economy More horsepower will consume more fuel

Characteristics of Air Flow:

Increases with horsepower Maximum Air Flow (g/sec) = Maximum Horsepower Restrictions effect horsepower and torque

Restrictions have very little effect on fuel economy

Air Flow

Technical Training 19

MIL ON Data List

Using Monitor Test Details

•

Technical Training 21

Misfire detection due to a catalyst over temperature [Data list → Cylinder # Misfire Count]

The misfire ratio is evaluated every 200 engine revolutions, and a DTC

is detected when a misfire has taken place three times at or above the threshold misfire ratio that causes a thermal deterioration in the catalyst (Two trip detection logic)

While a misfire is taking place under these conditions, the MIL blinks, regardless of the number of trips On some engines, the MIL will continue to blink after the catalyst over temperature conditions have passed On the next key cycle, the MIL will not blink until over temperature conditions occur in the catalytic converter

Misfire detection for a deteriorated level of emissions [Data list → All Cylinder Misfire Count]

The misfire ratio is evaluated every 1,000 engine revolutions, and a DTC is detected when a misfire has occurred at or above the threshold misfire ratio for a judgment of emission deterioration (Two trip

detection logic)

If this happens, the MIL stays ON

Misfire Detection

The Misfire Data List provides selected information related to cylinder misfire The Misfire Data Lists from OBD II and CAN OBD II vehicles will be different

Cylinder # Misfire Count

The Cylinder # Misfire Count parameter indicates how many times (0–100) the cylinder has misfired during the current ignition counter cycle A value above 0 indicates a misfiring cylinder For six- and eight- cylinder engines, the ECM may not set specific misfiring cylinder DTC(s) at high engine RPM and may only set DTC P0300 in this condition Diagnose the cylinder(s) with the highest Cylinder # Misfire Count first

Misfire Margin (CAN OBD II vehicles)

The Misfire Margin parameter indicates the percentage chance that

a misfire will NOT occur A negative percentage indicates a misfire

is occurring A high positive percentage indicates a low chance for a misfire to occur under the current conditions

Misfire Data List

continued

Basically, misfire margin is the difference between the predicted change in the NE signal to the actual change in the NE signal.

The Misfire Margin will move towards the negative region when misfiring is detected If it is under 30% there is a chance misfire is occurring If it is in the negative zone, misfire is occurring

This parameter is useful because it will change as the chance of a misfire increases

Misfire Margin

Technical Training 25

Catalyst Over Temperature Misfire Fuel CutThis can engage during a misfire The fuel injector is shut down when OFF changes to ON in the data list

Cat OT MF/FC

Cylinder Misfire Rate (Count)

& EWMA Misfire This section can identify:the number of misfires per cylinder

the total number of misfiresthe average of misfires from previous drive cyclesThe ECM counts misfires and is available under misfire test details.MISFIRE RATE – total misfire count for all cylinders

MISFIRE RATE 1 – number of misfire counts for cylinder 1Each count represents a cylinder misfire KOEO the test details provides the number of misfires from the last trip This is reset to zero after the engine has started

The Exponentially Weighted Moving Average (EWMA) Misfire count represents an average of cylinder misfires This value represents 10%

of the last trip’s misfires plus 90% of the average of the previous trips.Exponentially Weighted Moving Average (EWMA) Misfire Formula 0.1 x (current counts) + 0.9 x (previous average)

EWMA MISFIRE – total average for all cylindersEWMA MISFIRE 1 – average for cylinder 1

The cylinder and misfire count can be useful for the following situations

A customer reports the check engine lights was flashing, but now

1

it does not flash There is no DTC and the MIL is off This section can the EWMA can report which cylinder(s) had the misfire

Technical Training 27

The vehicle has P0300 DTC This section can show which cylinder

2

had the most misfires

The vehicle has a P0300 and multiple misfire DTCs Again, this

3

section can show which cylinder had the highest misfire counts

continued

Drive 1 Drive 2 Drive 3 Drive 4 Key On running Key Off Key On Engine Start

engine running Key Off Key On Engine engine Start running Key Off Key On Engine engine Start running Key Off Engine Cyl 1

Technical Training 29

Some 2006 and later model vehicles will display the speed of each cylinder During a Cylinder Compression active test with all spark plugs installed, if a single cylinder is rotating faster than other cylinders, this may indicate a mechanical issue with that cylinder

In the illustration, the spark plug was removed from cylinder number 4 and a Cylinder Compression active test was performed

It may be necessary to crank the engine for up to 20 seconds before accurate Engine Speed of Cyl # readings populate

Note Cylinder Speed Data List

210 210 210 285 210 228

MAF Oxygen Sensor

AF Sensor

AF & Oxygen Sensor Heater Operation

Section 3

Objectives

Overview of Sensor Operation

Update on MAF, AF, and the O2 sensor operation

• Verify fuel trim control operation

• Verify MAF sensor operation

•

Technical Training 31

Signal Circuit

The air flow meter is located in the intake air passage way The hot

• wire is located in the bypass way and cooled by intake air

The hot wire is controlled by the integrated circuit (IC) to keep its

• temperature constant, and so the current of the hot wire changes with a change in air volume This change in current is converted into a voltage signal by the built-in IC of the sensor and output to the ECM VG terminal

As air flow through the sensor increases, the VG voltage signal increases

Circuit Configuration of Mass

Air Flow Meter

As a result of an increase in MAF, the heating resistor (R1) is cooled and the resistance value decreased.

R1 × R4 < R2 × R3 (VM ≠ VK)

1

The current that flows from power terminal to

VB is increased to heat the heating resistor (R1).

Output terminal

GND terminal

Internal Circuit of Air Flow Meter

Fixed resistor (R3) Fixed resistor (R4)

Heating resistor (R1)

VB

The A/F sensor looks like an O2 sensor and serves the same purpose, but it is constructed differently and operates differently:

Instead of varying voltage output, the A/F sensor changes the

• circuit current in relation to the amount of oxygen in the exhaust stream A detection circuit in the ECM uses this to create a voltage signal that varies with the oxygen content of exhaust gases

A/F sensors detect air/fuel ratios over a wider range than O2

• sensors, allowing the ECM to more accurately control fuel injection and reduce emissions

A/F sensors operate at temperatures even hotter than O2 sensors,

• approximately 1200º F (650º C)

A/F Sensor Construction

Current models all have planar A/F sensors

Older cup element A/F sensors have a central heater element surrounded by the sensor element

Planar type A/F sensors integrate the sensor and heater elements

• The integrated heater is more efficient, bringing the sensor element to operating temperature more quickly for better sensor performance during engine warm-up

The heater amperage requirement is much lower for the planar type The planar type reaches operation temperature faster than the cup element type

A/F SensorDiffusion Layer

Technical Training 33

2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60 3.80 4.00 4.20

12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5-0.66

-0.54 -0.42 -0.30 -0.18 -0.06 0.06 0.18 0.30 0.42 0.54

A/F

Current and Voltage

Characteristic

AF sensor current voltage output

The direction of current flow depends on the amount of oxygen in the exhaust stream

When the AF is lean, current is in the positive direction and the signal voltage is higher

A/F Sensor Circuit