12 Auto Electricity and Electronics
Section 3—System Diagnosis and Repair
Chapter 23
On-Board Diagnostics and Scan Tools . . . . 439
On-Board Diagnostic Systems 440
Early On-Board Diagnostic Systems / On-Board
Diagnostics II (OBD II) / Malfunction Indicator Light
(MIL) / Diagnostic Trouble Codes / Computer System
Problems
Scanning Computer Problems 443
Scan Tool Program Cartridges / Data Link
Connector / Connecting the Scan Tool / Using Scan
Tools / Diagnostic Trouble Code Identifi cation / Failure
Types / Datastream Values / Engine-Off/Key-On
Diagnostics / Wiggle Test / Engine-On/Key-On
Diagnostics / Switch Diagnostic Test / Actuator
Diagnostic Tests / Scanning during a Test Drive
Energizing OBD I Systems without a Scan Tool 451
Reading Trouble Codes without a Scan Tool /
Reading the Flashing Check Engine Light / Reading
Voltmeter Needle Defl ections / Reading Digital and
LED Displays / Trouble Code Charts
Erasing Trouble Codes 454
Chapter 24
Sensor, Actuator, Computer Service . . . . . . 459
Preliminary Inspection 460
Cipet Principle / Kiss Principle / Scan Tool Information
Electrical Component Damage Precautions 460
Computer System Circuit Problems 461
Sensor and Actuator Problems 462
Poor Electrical Connections / Vacuum Leaks
Sensor Service 462
Engine Speed Sensor Service / Vehicle Speed Sensor
Service / Oxygen (O
2
) Sensor Service / Manifold
Absolute Pressure Sensor Service / Throttle Position
Sensor Service / Engine Coolant Temperature Sensor
Service / Intake Air Temperature Sensor Service /
Airfl ow Sensor Service / Fuel Sending Unit Service /
Water-In-Fuel Sensor Service / Knock Sensor Service /
Diesel Metering Valve Sensor Service
Actuator Service 474
Idle Speed Motor Service / Idle Air Control Valve
Service / Air Vent Solenoid Service / Glow Plug
Service / Servicing Other Actuators
Computer Service 476
Measuring Computer Output / Saving Memory
Contents / Computer Replacement / Computer
Adjustments / Updated PROMs / EEPROM
Programming Using Computerized Equipment /
EEPROM Programming Procedure / Replacing
Removable PROM / Computer Learn Procedures
Chapter 25
Battery and Starting System Service . . . . . . 483
Battery Service 484
Battery Inspection / Battery Leakage Test / Battery
Terminal Test
Battery Maintenance 486
Checking Battery Charge / Cleaning Battery Terminal
Connections / Cleaning Battery Top / Checking
Battery Hold-Down and Tray / Inspecting for
Physical Damage to Case and Terminals
Checking Battery Electrolyte 488
Hydrometer
Battery Voltage Test 489
Cell Voltage Test 489
Battery Load Test 489
Connect Load Tester / Double-Check Battery
Charge / Determine Battery Load / Load the
Battery / Load Test Results / Quick (Three-Minute)
Charge Test
Battery Chargers 491
Slow (Trickle) Charging Battery Chargers / Fast
(Boost) Charging Battery Chargers / Charging a
Battery
Other Battery-Related Problems 492
Battery Drain Test / Parasitic Loads
Jump Starting Battery 493
Activating Dry-Charged Battery 493
Removing and Replacing Battery 493
Starting System Diagnosis 493
Check Battery First / Starting Headlight Test / Starter
Current Draw Test / Starting System Voltage Drop
Test / Insulated Circuit Resistance Test / Starter
Ground Circuit Test
Battery Cable Problems 495
Testing Battery Cables / Replacing Battery Cables /
Starter Solenoid Service 496
Testing Starter Solenoid / Replacing Starter Solenoid
Ignition Switch Service 497
Testing Ignition Switch