BODY ELECTRICAL DIAGNOSIS Course 652 Technician Handbook © 2010 Toyota Motor Sales, U.S.A., Inc TOYOTA Technical Training All rights reserved This book may not be reproduced or copied, in whole or in part by any means, without the written permission of Toyota Motor Sales, U.S.A., Inc Revision Date: April 12, 2010 Table of Contents 652 Body Electrical Diagnosis Objectives Final Student Performances a Body Electrical Diagnosis Course Menu Section 1: Electrical Circuit Theory Topics .5 Automotive Electrical Circuits Load Voltage Sources Other Voltage Sources .10 Over-current Protection Devices .11 Control Devices 12 Conductors .13 Connectors .14 Circuit Operation .15 Principles of Electricity 16 Voltage 16 Voltage Measurements 17 Available Voltage 17 Open Circuit Voltage .18 Voltage Drop 19 Measuring Voltage Drop .20 Understanding Voltage Drops .20 Current 25 Measuring Amperage 26 Power 27 Resistance 28 Measuring Resistance 29 Basic Circuit Principles 30 Series Resistance 30 Parallel Resistance 31 Series-Parallel Resistance 32 Why Does it Matter? .32 Ohm’s Law 33 Applying Ohm’s Law 34 General Electrical Rules 35 Series Circuit Principles 36 Voltage 36 Resistance and Current 37 Series Circuit General Rules 37 Parallel Circuit Principles 42 Voltage 43 Backprobing a Connector .44 Resistance 45 Current .46 Parallel Circuit General Rules 46 Technical Training i Table of Contents 652 Body Electrical Diagnosis Section 2: Using the Electrical Wiring Diagram ii Topics 47 The Electrical Wiring Diagram 48 EWD Overview 49 The Index 49 System Circuits Index .50 EWD on TIS – 2005 MY and Earlier 51 EWD on TIS – 2006 MY and Later 52 “How to Use This Manual” 53 Troubleshooting Section 55 Connector Repair Information 56 Glossary of Terms and Symbols .57 Switch Positions 58 Tracing Current Flow 59 Abbreviated Illustrations 60 Gang-type Switches 61 Relays .63 Solid State Relays 64 Reading the System Circuit Diagram 65 System Outline 66 Service Hints 66 Important Notes 67 Wire Identification .68 Painted Wire Harnesses 69 Shielding 70 Components and Connectors .71 Component Locations .71 Component Connectors 72 Connector List 72 Multiple Component Connectors 73 Part Number of Connectors 74 Pin Numbering 75 Color Coding 75 Junction Blocks and Relay Blocks 76 Junction Blocks .76 Junction Block Location 77 J/B Inner Circuit 78 Relay Blocks .79 Junction Connectors, Harness Connectors and Splice Points .80 Junction Connectors 80 Junction Connector Connectors .81 Wire Harness Connectors .83 Harness Connector Identification 84 Splice Points .85 Power Source Diagrams .86 Power Source System Diagram 86 Power Source (Current Flow Chart) 87 Technical Training Table of Contents 652 Body Electrical Diagnosis Ground Points .88 Shared Ground Points 89 Overall Wiring Diagram .90 Finding System Circuit Diagrams on TIS 92 Finding Other Resources 92 TIS Diagrams through the 2005 MY 93 2006 MY Changes to EWD 94 Using the EWD Viewer .95 Help Tab 96 Finding System Circuit Diagrams in the EWD Viewer 97 System Circuit Diagrams 98 System Outline 99 System Hints 99 Components Location Using EWD Viewer .100 Component Connectors in the EWD Viewer 101 Junction Block Location in the EWD Viewer 102 J/B Inner Circuit Using EWD Viewer .103 Harness Connectors in EWD Viewer 104 Splice Information for 2006 MY and Later 107 Power Source System Diagram in EWD Viewer 108 Power Source Tab in EWD Viewer .109 Ground Points in EWD Viewer 110 Shared Ground Points in EWD Viewer 111 Finding Additional Information 112 Other Sources of Information 115 Section 3: Electrical Diagnostic Tools Technical Training Topics 117 Introduction 118 Visual Inspection .118 Operate the Circuit Thoroughly .118 Checking Connectors & Terminals 119 Excessive Terminal Spread 120 Wire Harness Inspection .121 Visual Inspection Hints .121 Jumper Wires 122 Digital Multimeters 123 Additional Meter Features .123 Digital Voltmeters 124 Measuring Pin Voltage 124 Why a Good DVOM is Safe 124 Voltage Drop Measurement 125 Available Voltage Measurement .130 Measuring Voltage Drop by Subtraction 131 Digital Ammeter 134 Series Type Ammeter .135 Clamp Type (Inductive Ammeter) 136 iii Table of Contents 652 Body Electrical Diagnosis Digital Ohmmeter 137 Ohmmeter Common Mistakes 137 Audible Continuity Beep 138 Diode Check 139 iv Section 4: 6-Step Diagnostic Process Topics 141 Introduction 142 6-Step Diagnostic Process 142 Step #1 – Verify the Complaint 143 Identify the Problem 143 Does a Problem Exist? 143 Intermittent or Continuous? 144 Step #2 – Determine the Related Symptoms .145 Perform a Thorough Operational Check .145 How a Circuit is Related 146 How Much of the Circuit is Affected? .146 Circuits with Self-Diagnosis 147 Step #3 – Analyze the Symptoms .148 If Entire Circuit is Inoperative 149 If Any Part of the Circuit Works .150 Eliminate Parts of the Circuit 150 Trace the Paths of Current Flow 151 Step #4 – Isolate the Problem 152 Finding Possible Problem Areas .153 Where to Begin .153 The Split-Half Method .154 Step #5 – Correct the Trouble 155 Component Service Hints .155 Step #6 – Check for Proper Operation .156 Section 5: Diagnosing Body Electrical Problems Topics 159 Introduction 160 Diagnosing Open Circuit Problems 160 Using a Voltmeter on Open Circuit Problems 161 High Resistance Problems 168 Causes of a High Resistance Problem 168 Diagnosing High Resistance Problems 169 Determine if There is Current Flow in the Circuit 169 Isolating a High Resistance Problem 170 Parasitic Load .178 How to Measure Parasitic Load 179 Diagnosing Parasitic Load 181 Disconnecting Components 182 Procedure for Mapping Current Flow Through the J/Bs 183 Diagnosing Shorts to Grounds 184 Inspect the Fuse .184 Short to Ground Diagnostic Strategy 184 Technical Training Table of Contents 652 Body Electrical Diagnosis Selecting a Load .185 Using a Headlamp as a Load 185 Intermittent or Continuous? 186 Disconnecting Component Connectors 186 Feedback Problems 194 Diagnosing a Feedback Problem 194 Quick Checks for Lighting Circuits 195 Quick Checks for General Feedback Problems 195 If the Quick Checks Do Not Find the Cause 196 Appendix EWD Section H: How to Use This Manual A-1 Worksheets Technical Training v Table of Contents 652 Body Electrical Diagnosis This page intentionally left blank vi Technical Training Objectives 652 Body Electrical Diagnosis Course 652 Body Electrical Diagnosis Final Student Performances Terminal Objective (Terminal FSP) Given a vehicle with any of the conditions listed below, the appropriate tools & equipment, and access to the vehicle’s EWD, the technician will be able to use the six-step diagnostic process to identify the type of fault and its location, and explain/demonstrate the correct repair procedure • Short-to-ground • Open in a non-MPX circuit • High resistance in a non-MPX circuit • Feedback Problem Technician Objectives (FSPs) Given a 2010 Camry "Back-up Light System Circuit" the technician will be able to predict voltage, amperage, and resistance values at various location on the diagram under a variety of conditions (both normal and abnormal operation) and based upon the principals outlined below: Series Circuits • When there is only one load in the circuit, all the voltage is used up in that load • When there are multiple loads in the circuit, voltage is divided according to the resistance of the loads The load with the most resistance will use the most voltage; the load with the least resistance will use the least voltage; The voltage used is directly proportional to the resistance • Amperage is the same throughout the circuit This means that an ammeter can be connected anywhere in the circuit and measure the amperage • Total resistance is the sum of all the resistance in the circuit Adding a resistance in series will increase the total resistance and decrease current (amperage) Parallel Circuits • The voltage applied to each branch of a parallel circuit is the same • The current in a branch is determined by the branch's resistance The branch with the least resistance will have the most current • Total resistance decreases as branches are added Adding a branch lowers the total resistance and increases current The total circuit resistance is always lower than the lowest branch resistance Series-Parallel Circuits • Problems in the series portion of a series-parallel circuit affect the entire circuit Problems in a parallel branch of a series parallel circuit affect only the branch where the problem is located Technical Training a Objectives 652 Body Electrical Diagnosis Given access to the EWD, technician will be able to demonstrate his knowledge of what’s available in the EWD by locating the following sections and features (paper version and on TIS EWD Viewer): • Locate assigned System Circuit Diagrams in the EWD • Identify each of the symbols used on the system diagram, wire color wire identification, and pin number location • Locate, How to use the Manual; Abbreviations; Glossary of Terms & Symbols: Relay Locations & JB Inner Circuit Diagram; Relay Blocks; Connector List; Part Numbers of Connectors; Overall Electrical Wiring Diagram; and support sections, System Outline & Service Hints • Locate components, ground points, connectors, junction blocks, harness to harness connectors; switches; relays; splice points; in the manual and on the vehicle • Power source section and ground point section and describe how each is used when diagnosing a problem Given a 2010 Camry Remote Control Mirror System Circuit Diagram and a Radiator & Condenser Fan System Circuit Diagram the technician will be able to: • Apply basic current flow theory to the diagram by tracing the path of current flow through the circuit from B+ to ground • Configure the switches/relays in the circuit to the appropriate positions for the operating conditions described • Identify the symbols used on the system circuit diagram • Predict voltage, amperage, and resistance values at various locations on the diagram under a variety of conditions (normal and abnormal operation) Given a DVOM with an inductive clamp and a simple System Circuit Diagram, the technician will be able to demonstrate how to: b • Make resistance, current measurements • Measure open circuit voltage, available voltage and voltage drop • Properly identify a parasitic load in a circuit Technical Training Objectives 652 Body Electrical Diagnosis Given different customer concerns (4 with full class participation and in teams of two), all of the appropriate tools and equipment, a vehicle(s) with select “faults” installed, and access to the vehicle’s EWD, the technician will be able to demonstrate his ability to apply the Six-step Diagnostic Process to: • • • • • Verify the customer concern by: - Duplicating the problem the Customer is describing - Identifying what circuit is involved in the concern - Locating information related to what is normal operation and customized settings for that circuit - Determining if it is a problem, a normal operating condition or a customized setting - Identifying the conditions under which the problem occurs Determine the related symptoms by: - Identifying how much of the circuit is affected - Identifying related circuits and determining if problems exist in those circuits - Determining if DTCs are present Analyze the problem by: - Defining exactly which components/circuits are affected based on both the customer's concern and any related symptoms - Defining what kind of problem to look for (open, short-to-ground, high resistance, feedback) - Identifying when the problem occurs (what operating conditions: key ON, driver's door open, etc.) - Identifying on the wiring diagram where the problem could possibly be located - Determining what tests to perform first, what tools to use, and what results to expect - Determining the easiest place to begin making the checks (split half method) Isolate the problem by: - Performing initial tests - Determining the logical place to test next and predicting the expected results for a normally operating circuit Identify and describe the correct repair for the problem, such as: - Replacing a wire harness - Performing a proper repair to wiring, connections, connectors, or terminals - Replacing a component Technical Training c Objectives 652 Body Electrical Diagnosis • d Describe the proper verification of the repair by: - Confirming the problem has been eliminated and that no new problems have been created by the repair - Locating information regarding what initializations need to be performed following the repair - Verifying all necessary initializations have been performed Technical Training Technician Handbook 652 Body Electrical Diagnosis Technical Training Technician Handbook 652 Body Electrical Diagnosis This page is intentionally blank Technical Training Technician Handbook 652 Body Electrical Diagnosis Technical Training Technician Handbook 652 Body Electrical Diagnosis This page is intentionally blank Technical 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Technical Training v Table of Contents 652 Body Electrical Diagnosis This page intentionally left blank vi Technical Training Objectives 652 Body Electrical Diagnosis Course 652 Body Electrical Diagnosis. .. Technical Training Technician Handbook 652 Body Electrical Diagnosis Technical Training Technician Handbook 652 Body Electrical Diagnosis This page is intentionally blank Technical Training Technician... Training Technician Handbook 652 Body Electrical Diagnosis Technical Training Technician Handbook 652 Body Electrical Diagnosis This page is intentionally blank Technical Training