About Me
Automotive Service Technician
1 Introduction to Automotive Technology
1-1 Overview of Automotive Industry
1-2 Importance of Automotive Service Technicians
1-3 Safety Procedures in Automotive Workshop
1-4 Introduction to Automotive Tools and Equipment
2 Automotive Systems and Components
2-1 Engine Systems
2-1 1 Engine Construction and Operation
2-1 2 Engine Cooling System
2-1 3 Engine Lubrication System
2-1 4 Engine Fuel System
2-1 5 Engine Ignition System
2-2 Transmission Systems
2-2 1 Manual Transmission
2-2 2 Automatic Transmission
2-2 3 Continuously Variable Transmission (CVT)
2-3 Suspension and Steering Systems
2-3 1 Suspension Components
2-3 2 Steering Mechanisms
2-4 Braking Systems
2-4 1 Hydraulic Braking System
2-4 2 Anti-lock Braking System (ABS)
2-5 Electrical and Electronic Systems
2-5 1 Vehicle Electrical Systems
2-5 2 Electronic Control Units (ECUs)
2-5 3 Sensors and Actuators
3 Diagnostic and Testing Procedures
3-1 Diagnostic Tools and Equipment
3-1 1 Multimeters
3-1 2 Scan Tools
3-1 3 Pressure Gauges
3-2 Engine Diagnostic Procedures
3-2 1 Compression Testing
3-2 2 Fuel Pressure Testing
3-2 3 Ignition System Testing
3-3 Transmission Diagnostic Procedures
3-3 1 Transmission Fluid Analysis
3-3 2 Transmission Scan Tool Diagnostics
3-4 Electrical Diagnostic Procedures
3-4 1 Circuit Testing
3-4 2 Sensor Testing
4 Maintenance and Repair Procedures
4-1 Engine Maintenance and Repair
4-1 1 Spark Plug Replacement
4-1 2 Air Filter Replacement
4-1 3 Oil and Filter Change
4-2 Transmission Maintenance and Repair
4-2 1 Transmission Fluid Change
4-2 2 Clutch Adjustment and Replacement
4-3 Suspension and Steering Maintenance and Repair
4-3 1 Shock Absorber Replacement
4-3 2 Ball Joint Replacement
4-4 Braking System Maintenance and Repair
4-4 1 Brake Pad and Shoe Replacement
4-4 2 Brake Fluid Flush
4-5 Electrical System Maintenance and Repair
4-5 1 Battery Replacement
4-5 2 Wiring Harness Inspection and Repair
5 Customer Service and Communication Skills
5-1 Customer Interaction
5-1 1 Effective Communication Techniques
5-1 2 Handling Customer Complaints
5-2 Job Estimation and Quotation
5-2 1 Estimating Repair Costs
5-2 2 Preparing Repair Quotations
5-3 Record Keeping and Documentation
5-3 1 Maintenance Records
5-3 2 Repair Orders and Invoices
6 Professional Development and Industry Standards
6-1 Continuous Learning and Skill Development
6-1 1 Industry Training Programs
6-1 2 Certification and Licensing Requirements
6-2 Ethical Practices in Automotive Service
6-2 1 Code of Ethics for Technicians
6-2 2 Environmental Considerations in Automotive Service
6-3 Industry Trends and Innovations
6-3 1 Introduction to Electric and Hybrid Vehicles
6-3 2 Advancements in Automotive Technology
3 Diagnostic and Testing Procedures Explained

3 Diagnostic and Testing Procedures Explained

Key Concepts

Multimeter Usage

A multimeter is an essential tool for diagnosing electrical issues in a vehicle. It measures voltage, current, and resistance. To use a multimeter:

  1. Set the multimeter to the appropriate measurement mode (voltage, current, or resistance).
  2. Connect the multimeter probes to the circuit or component you want to test.
  3. Read the measurement on the multimeter display.

For example, to check the battery voltage, set the multimeter to DC voltage, connect the red probe to the positive terminal and the black probe to the negative terminal, and read the voltage. A healthy battery should read around 12.6 volts when fully charged.

Think of the multimeter as a doctor's stethoscope. Just as a stethoscope listens to the heart, the multimeter measures the electrical health of a vehicle.

Diagnostic Scan Tool

A diagnostic scan tool, or OBD-II scanner, reads and clears diagnostic trouble codes (DTCs) from the vehicle's onboard computer. To use a diagnostic scan tool:

  1. Connect the scan tool to the vehicle's OBD-II port, usually located under the dashboard.
  2. Turn on the vehicle's ignition but do not start the engine.
  3. Follow the scan tool's instructions to read and clear the codes.

For example, if the check engine light is on, connect the scan tool, read the codes, and use a repair manual or online resources to interpret the codes and diagnose the issue.

Consider the diagnostic scan tool as a translator for the vehicle's computer. Just as a translator converts one language to another, the scan tool converts the computer's codes into information that technicians can understand.

Compression Test

A compression test measures the pressure inside each engine cylinder. It helps diagnose issues such as worn piston rings, valves, or cylinder head gaskets. To perform a compression test:

  1. Warm up the engine to normal operating temperature.
  2. Disconnect the ignition coil or spark plug wires.
  3. Install a compression tester in the spark plug hole.
  4. Crank the engine and read the compression pressure on the tester.

For example, if the compression readings are significantly lower in one cylinder compared to others, it may indicate a problem with that cylinder, such as worn piston rings or a faulty valve.

Think of the compression test as a blood pressure check for the engine. Just as blood pressure indicates the health of the cardiovascular system, compression readings indicate the health of the engine's cylinders.

Conclusion

Understanding and effectively using diagnostic and testing procedures is crucial for any Automotive Service Technician. By mastering the multimeter, diagnostic scan tool, and compression test, you can accurately diagnose and repair a wide range of vehicle issues, ensuring optimal performance and reliability.

© 2024 Ahmed Baheeg Khorshid. All rights reserved.