Automotive Diagnostic Systems: Understanding Obd-i And Obd-ii by Keith MccordAutomotive Diagnostic Systems: Understanding Obd-i And Obd-ii by Keith Mccord

Automotive Diagnostic Systems: Understanding Obd-i And Obd-ii

byKeith Mccord

Paperback | July 21, 2011

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The electronic control unit and other electronic controls are connected to every major system of a car built within the past 15 years, yet when there is a problem or an error code, many enthusiasts do not know how to go about fixing the problem. With this book, an affordable hand held scanner, and other common tools, the average enthusiast can diagnose and fix most common problems, rather than bringing the vehicle to a dealership for repair at shop rates of $100 per hour or more.

Keith McCord recounts the history of automotive onboard diagnostic systems and creation of the rudimentary OBD I systems and the development as well as the evolution of OBD II. Currently, OBD-II (OnBoard Diagnostic II) is the standard of the industry, and this book provides a thorough explanation of this system. It details its main features, capabilities, and characteristics. It shows how to access the port connector on the car, the serial data protocols, and what the serial data means. To understand the diagnostic codes, the numbering system is defined and the table of common DTCs is shown. But most importantly, McCord provides a thorough process for trouble shooting problems, tracing a problem to its root, explaining why DTCs may not lead to the source of the underlying problem, and ultimately resolving the problem.

Almost anyone can hook a scanning tool up to the serial port and read the error, but the key to fixing the problems is using an effective trouble shooting process that resolves all the issues that may be contributing or creating the problem. McCord provides sound procedures, insight, and information for resolving most ECU and computer control problems at home with affordable consumer-grade scanners.

Keith McCord, who is located in the St. Louis area, is one of top OBD II technicians and EFI tuners in the country. He is president of McCord Consulting Group in St. Louis, Missouri. He designs products, parts, and CNC code and process improvements for various OEM and aftermarket companies. Keith also writes custom ECMs for GM and Ford...
Title:Automotive Diagnostic Systems: Understanding Obd-i And Obd-iiFormat:PaperbackDimensions:144 pages, 11 × 8.5 × 0.38 inPublished:July 21, 2011Publisher:CartechLanguage:English

The following ISBNs are associated with this title:

ISBN - 10:1934709069

ISBN - 13:9781934709061

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Table of Contents


Chapter 1: Introduction to On-Board Diagnostics 
Closed-Loop Feedback Systems 
Pre-OBD Emissions Requirements 
Automotive On-Board Diagnostics 
Proprietary OBD: 1980&1987 
Has OBD Made a Difference? 

Chapter 2: OBD-II Standardization 
The Power of the Microchip 
Evolution of Automotive Networks 
Standardized ALDL Connector 
Standardized Scan Tool Data 
Diagnostic Trouble Codes 
The MIL 
Frame-to-Frame Data 
Real-Time Data 
What Information Does OBD-II Provide? 
SAE Standards versus ISO Standards 

Chapter 3: The OBD-II Data Interface 
Data Link Connector 
Determining if the Vehicle is OBD-II 
OBD-II Data Protocols 
Serial Communications Protocols 
Troubleshooting Common DLC Connection Problems 

Chapter 4: Scan Tool Interfaces 
Generic OBD-II Scan Tool 
Manufacturer-Specific OBD-II Scan Tool 
Reading Scan Data 
OBD-II Trouble Code Reader 
Entry-Level OBD-II Scan Tool 
Professional-Level OBD-II Scan Tool 
Personality Keys and Adapters 
Manufacturer-Specific OBD-II Scan Tool 
Personal-Computer-Based OBD-II Scan Tool 

Chapter 5: OBD-II Modes 
Mode $01 & Request Data by Specific PID 
Mode $02 & Request Freeze-Frame Data by Specific PID 
Mode $03 & Request Set Diagnostic Trouble Codes 
Mode $04 & Clear Stored Diagnostic Trouble Codes and Reset MIL 
Mode $05 & Oxygen Sensor Test Results 
Mode $06 & Advanced Diagnostic Mode 
Mode $07 & Request On-Board Monitor Test Results 
Mode $08 & Control Operations of On-Board Systems 
Mode $09 & Vehicle Information 

Chapter 6: Diagnostic Trouble Codes 
OBD-II Drive Cycle 
Anatomy of a Diagnostic Trouble Code 
Pending Diagnostic Trouble Codes 
Diagnostic Trouble Code Types 
Current and Historical Diagnostic Trouble Codes 
Plan Your Work and Work Your Plan 

Chapter 7: Freeze-Frame Data 
Freeze-Frame Data Reports 
Freeze-Frame Data Summary 
Historical Freeze-Frame Data 
Breaking Down Freeze-Frame Data 
Using the Freeze-Frame Data Example

Chapter 8: Emissions Tests and System Monitors 
Emissions Tests 
System Monitors 
Misfire Monitor 
Evaporative System Monitor 
Heated Catalyst Monitor and Catalyst Efficiency Monitor 
Secondary Air System Monitor 
Fuel System Monitor 
Oxygen Sensor Monitor and Heated Oxygen Sensor Monitor 
EGR System Monitor 
Comprehensive Component Monitor 

Chapter 9: Four-Stroke Engine Cycle 
Intake Cycle 
Compression Cycle 
Combustion Cycle 
Exhaust Cycle 
Otto Cycle Pressure versus Volume 

Chapter 10: OBD-II and the Otto Engine Model 
Pressure and Vacuum 
Supercharging/Turbocharging versus Normally Aspirated 
Crank, Camshaft and Valves 
Static versus Dynamic Compression Ratios 

Chapter 11: Controlling Fuel Systems
Closed-Loop is the Key 
Fuel Combustion and Thermal Efficiency 
Volumetric Efficiency 
Airflow Volume 
What Can Go Wrong? 
Evolution of the ECM 

Chapter 12: Dynamic Fuel Correction 
Fuel Requirements 
In a Perfect World 
Fuel-Trim Adjustments 
Real-Time Fuel-Trim Adjustments 
Historical Fuel-Trim Adjustments 
DTCs Related to Fuel Trims 
P0171 and P0174 DTC Fuel-Trim System Lean 
P0172 and P0175 DTC Fuel-Trim System Rich 

Chapter 13: Engine Ignition Controls 
What is Ignition Timing? 
Generating High Voltage 
Knowing When to Fire 
Controlling the Timing 
Sensors that Affect Timing 
Detonation and Pre-Ignition 
The ECM and Detonation 
What Causes Detonation and Pre-Ignition? 

Chapter 14: Misfires 
Misfire Types 
OBD-II Misfire Detection 
P030x Misfire DTC 
Diagnosing a Misfire 
Frame-to-Frame Data 
Blinking MIL 
False Misfire Code 

Chapter 15: Sensors 
Intake Air Temperature Sensor (IAT) 
Engine Coolant Temperature Sensor (ECT) 
Throttle Position Sensor (TPS) 
Camshaft Position Sensor (CMP) 
Crankshaft Position Sensor (CKP) 
Manifold Absolute Pressure (MAP) Sensor 
Mass Air Flow (MAF) Sensor 

Chapter 16: Oxygen Sensors 
Oxygen Sensors Are Consumable 
How an Oxygen Sensor Works 
Diagnosing an Oxygen Sensor 
Oxygen Sensor Codes 
What Causes Oxygen Sensor Failure? 
Replacing an Oxygen Sensor 


Appendix A: Using a Volt Ohm Meter 

Appendix B: Generic OBD-II DTC Codes 

Appendix C: Manufacturer-Specific OBD-II DTC Codes