Table of Contents 9
Chapter 13
Troubleshooting Techniques . . . . . . . . . . . . 241
Basic Diagnostic Procedures 242
Learning to Diagnose; Evaluating Customer Input;
Filling Out Work Orders; Obtaining Vehicle
Identification Numbers; Road Testing; Performing
Visual Inspections; Principles of Diagnosis; Using
Service Information; Diagnosing Electrical Problems;
Diagnosing Charging and Starting Systems;
Diagnosing Engine Problems; Diagnosing Computer
Control Systems; Diagnosing Drive Train Problems;
Diagnosing Other Vehicle Systems
Deciding on Needed Work 256
Always Perform Additional Tests; Deciding on the
Proper Repair Steps; Contacting the Owner about
Needed Work
Follow-Up After Repairs 258
Chapter 14
Electrical System Diagnosis and Repair. . . . 261
Identifying Driveability Problems
Caused by the Electrical System 262
Preparing to Diagnose Electrical Problems 262
Using Schematics to Diagnose Electrical Problems;
Visual Inspection
Test Equipment Used to Diagnose
Electrical Problems 268
Using Jumper Wires; Using Test Lights; Using an
Ammeter; Using a Voltmeter; Using an Ohmmeter;
Graphing Multimeter
Checking Specific Components 271
Testing Relays; Testing Ignition Coils; Testing
Solenoids; Testing Servo Motors; Testing Solid-State
Components
Electrical Repair Operations 274
Repairing Damaged Wiring; Replacing Fusible Links;
Disassembling Connectors; Repairing Connectors
Checking Starting and Charging Systems 276
Battery; Starting System; Alternator
Follow-up for Electrical Repairs 282
Chapter 15
Computer Control System Diagnosis
and Repair . . . . . . . . . . . . . . . . . . . . . . . . . 287
Beginning Computer Control Diagnosis 288
Retrieving ECM Trouble Codes 289
Code Retrieval Process; Diagnostic Trouble Code
Format; Interpreting Trouble Codes; Comparing
Hard and Intermittent Codes; Separating Hard and
Intermittent Codes; When There Are No Trouble
Codes
Interpreting Scan Tool Data 293
Using the Misfire Monitor 294
Computer Sensor and System Testing 294
Testing Oxygen Sensor Operation; Testing Mass
Airflow (MAF) Sensors; Testing Manifold Absolute
Pressure (MAP) Sensors; Testing Temperature
Sensors; Testing Throttle Position Sensors; Testing
Crankshaft and Camshaft Position Sensors; Testing
Knock Sensors; Testing Vehicle Speed Sensors;
Testing Output Devices with a Scan Tool
Replacing Components in the Computer Control
System 303
Oxygen Sensor Replacement; MAF and MAP
Sensor Replacement; MAF Sensor Cleaning;
Throttle Position Sensor Replacement; Temperature
Sensor Replacement; Knock Sensor Replacement;
Crankshaft/Camshaft Position Sensor Replacement
ECM Replacement 306
ECM Removal; ECM Memory Chip Replacement;
ECM Installation; ECM Programming; OBD II Drive
Cycle
Follow-Up for Computer Control System
Repairs 310
Chapter 16
Ignition System Diagnosis and Repair. . . . . 315
Preparing to Diagnose the Ignition System 316
Visual Inspection 316
Corona Discharge; Tests Performed During the
Visual Inspection; Scan Tool Testing; OBD II Misfire
Monitor
Checking the Ignition System
Using Test Equipment 319
Using a Scope; Using a Timing-Checking Device;
Using an Ohmmeter
Checking Ignition Coils 327
Checking Spark Plugs 328
Checking the Distributor, Cap, and Rotor 329
Testing Ignition Pickup Devices 329
Testing a Magnetic Pickup Coil for a Sine Wave
Signal; Testing a Hall-Effect Switch for a Square Wave
Signal; Testing Pickup Coils and Hall-Effect Switches
with an Ohmmeter; Adjusting Pickup Coil Air Gap