Toyota training body electrical diagnosis intro

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 co

© 2010 Toyota Motor Sales, U.S.A., Inc

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

TOYOTA Technical Training

BODY ELECTRICAL DIAGNOSIS

Course 652 Technician Handbook

Table of Contents

652 Body Electrical Diagnosis

Technical Training i

Objectives Final Student Performances .a

Body Electrical

Diagnosis Course Menu 3

Section 1: Electrical Circuit Theory Topics 5

Automotive Electrical Circuits 7

Load 8

Voltage Sources 9

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

Section 2:

Using the

Electrical Wiring

Diagram

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

Table of Contents

652 Body Electrical Diagnosis

Technical Training iii

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 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

Digital Ohmmeter 137

Ohmmeter Common Mistakes 137

Audible Continuity Beep 138

Diode Check 139

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

Table of Contents

652 Body Electrical Diagnosis

Technical Training v

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

This page intentionally left blank

Objectives

652 Body Electrical Diagnosis

Technical Training a

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)

1 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

b Technical Training

2 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

3 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)

4 Given a DVOM with an inductive clamp and a simple System Circuit Diagram, the

technician will be able to demonstrate how to:

• Make resistance, current measurements

• Measure open circuit voltage, available voltage and voltage drop

• Properly identify a parasitic load in a circuit

Objectives

652 Body Electrical Diagnosis

Technical Training c

5 Given 8 different customer concerns (4 with full class participation and 4 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

d Technical Training

• 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

652 Body Electrical Diagnosis

This page is intentionally blank

652 Body Electrical Diagnosis

This page is intentionally blank