In the realm of automotive diagnostics, understanding how to effectively use an OBD2 scanner is a crucial skill for any Certified Automotive Technician or enthusiastic car owner. This comprehensive guide aims to demystify the process, providing step-by-step instructions on utilizing an OBD2 scanner for troubleshooting various vehicle issues. Whether you’re a seasoned professional or a passionate automotive enthusiast, this guide will empower you with the knowledge to navigate the intricacies of OBD2 diagnostics, allowing you to pinpoint and address potential issues with precision. Let’s embark on a journey into the world of On-Board Diagnostics and harness the capabilities of OBD2 scanners to ensure optimal performance and reliability in your vehicle.

What is an OBD2 Scanner?

An OBD2 (On-Board Diagnostics II) scanner is a specialized tool designed to interface with a vehicle’s onboard computer system, providing access to valuable diagnostic information. It typically connects to the OBD2 port, a standardized connector located beneath the dashboard in most vehicles produced after 1996. The scanner communicates with the car’s Engine Control Module (ECM) and other onboard systems, retrieving data related to engine performance, emissions, and various subsystems.

These scanners come in various forms, ranging from handheld devices with a small screen to more advanced tools that connect to smartphones or tablets. OBD2 scanners can read and interpret Diagnostic Trouble Codes (DTCs), which are generated when the vehicle’s computer detects a problem. Additionally, these scanners often offer real-time data monitoring, allowing users to observe live parameters such as engine RPM, coolant temperature, and sensor readings.

OBD2 scanners play a pivotal role in automotive diagnostics, enabling technicians and car enthusiasts to identify issues, perform maintenance, and clear fault codes. With the ability to access a wealth of information, these scanners contribute significantly to efficient troubleshooting and maintenance in the automotive industry.

OBD Communication Protocol (ISO 15031):

The On-Board Diagnostics (OBD) communication protocol, standardized under ISO 15031, defines the way electronic control units (ECUs) in vehicles communicate with external diagnostic tools. This protocol ensures a standardized method for accessing and retrieving information from a vehicle’s onboard systems.

In the Society of Automotive Engineers (SAE) standard J1979, which aligns with ISO 15031, the concept of “modes” was later renamed to “services” starting in 2003. These services represent different diagnostic functions that an external tool can request from the vehicle’s ECUs. Here is a list of the common OBD services or modes according to SAE J1979:

1. Service 01 (01h) – Show Current Data / Live Data:
   • Requests real-time data from various sensors and systems in the vehicle, such as engine RPM, vehicle speed, and coolant temperature.
2. Service 02 (02h) – Show Freeze Frame Data:
   • Retrieves a snapshot of data captured at the moment a Diagnostic Trouble Code (DTC) is set. This includes information about vehicle parameters at the time of the fault.
3. Service 03 (03h) – Show Stored Diagnostic Trouble Codes (DTCs):
   • Requests and displays diagnostic trouble codes that have been stored in the vehicle’s memory.
4. Service 04 (04h) – Clear Diagnostic Trouble Codes (DTCs):
   • Instructs the vehicle’s ECU to clear or reset stored diagnostic trouble codes, turning off the “Check Engine” light.
5. Service 05 (05h) – Test Results, Oxygen Sensor Monitoring (Non-Continuous Monitors):
   • Provides information about the status of oxygen sensor monitoring tests.
6. Service 06 (06h) – Show Pending Diagnostic Trouble Codes (DTCs):
   • Retrieves diagnostic trouble codes that have been detected but not yet confirmed during a specific drive cycle.
7. Service 07 (07h) – Show Onboard Systems or Components:
   • Displays information about the status and availability of various onboard systems or components.
8. Service 08 (08h) – Control Operation of Onboard Systems or Components:
   • Allows the external tool to control or test certain onboard systems or components, such as activating relays or solenoids.
9. Service 09 (09h) – Request Vehicle Information:
   • Retrieves essential information about the vehicle, including the Vehicle Identification Number (VIN), calibration IDs, and other details.
10. Service 0A (0Ah) to Service 1F (1Fh) – Reserved for Future Use:
    • These services are reserved for potential future enhancements or expansions of the OBD communication protocol.

These services, formerly referred to as modes, facilitate standardized communication between external diagnostic tools and a vehicle’s onboard systems, enabling efficient diagnostics and troubleshooting.

Mode/Service 01 (01h) – Show Current Data / Live Data:

The “Show Current Data” or “Live Data” service, denoted by Service 01 (01h) in the OBD communication protocol according to SAE J1979 (aligned with ISO 15031), is a diagnostic function that enables an external OBD2 scanner or diagnostic tool to request and display real-time data from various sensors and systems within a vehicle. This service provides immediate access to dynamic information about the vehicle’s operating conditions.

Here’s an explanation of the “Show Current Data” or “Live Data” service:

Why Show Current Data / Live Data:

1. Real-Time Monitoring: This service allows technicians and users to monitor and observe live parameters from different components and systems in the vehicle in real-time.
2. Dynamic Diagnostics: Live Data provides a dynamic snapshot of the vehicle’s performance, enabling the identification of issues that may only occur under specific driving conditions.
3. Performance Optimization: Monitoring live data helps optimize the vehicle’s performance by assessing parameters such as engine RPM, temperature, and sensor readings.

How Show Current Data / Live Data Works:

1. OBD2 Scanner Connection: Connect an OBD2 scanner to the vehicle’s OBD2 port, establishing communication with the Engine Control Module (ECM) and other onboard systems.
2. Selecting Service 01 – Show Current Data / Live Data: Navigate through the OBD2 scanner menu to find and select Service 01 – Show Current Data / Live Data.
3. Selecting Parameters: The user or technician chooses specific parameters they want to monitor from a list provided by the OBD2 scanner. Parameters may include engine RPM, vehicle speed, coolant temperature, oxygen sensor readings, and more.
4. Real-Time Data Retrieval: The OBD2 scanner sends requests to the ECM for the selected parameters, and the ECM responds by providing real-time data readings for those parameters.
5. Displaying Results: The OBD2 scanner displays the live data on its screen in real-time. The data may be presented as numerical values, graphical representations, or charts, depending on the capabilities of the scanner.
6. Observation and Analysis: Technicians and users observe the live data to assess the vehicle’s performance. They look for abnormalities, fluctuations, or patterns that may indicate potential issues or areas for optimization.
7. Diagnostic Decision-Making: Based on the observed live data, technicians can make diagnostic decisions, identify potential problems, and plan further diagnostic procedures or necessary repairs.
8. Performance Optimization: For automotive enthusiasts or professionals, the live data can be used to optimize the vehicle’s performance by making informed adjustments based on real-time feedback.

The “Show Current Data” or “Live Data” service is a powerful diagnostic tool that provides immediate insights into the real-time functioning of a vehicle’s various components and systems. It is instrumental in dynamic diagnostics, performance optimization, and identifying issues that may only manifest under specific driving conditions.

Mode/Service 02 (02h) – Show Freeze Frame Data:

The “Show Freeze Frame Data” service, denoted by Service 02 (02h) in the OBD communication protocol according to SAE J1979 (aligned with ISO 15031), is a diagnostic function that allows an external OBD2 scanner or diagnostic tool to retrieve and display a snapshot of data captured at the moment a Diagnostic Trouble Code (DTC) is set. This snapshot is commonly referred to as “Freeze Frame Data.”

Here’s an explanation of the “Show Freeze Frame Data” service:

Why Show Freeze Frame Data:

1. Snapshot of Fault Conditions: Freeze Frame Data provides a snapshot of the vehicle’s operating conditions at the time a fault is detected, offering valuable information about what was happening when a Diagnostic Trouble Code (DTC) was triggered.
2. Context for Diagnosis: Understanding the circumstances surrounding the activation of a fault code can help technicians diagnose issues more effectively. Freeze Frame Data serves as contextual information for troubleshooting.
3. Enhanced Diagnostics: Freeze Frame Data includes parameters such as engine RPM, vehicle speed, coolant temperature, and other sensor readings at the time of the fault. This data enhances diagnostic precision by providing a detailed context for the detected issue.

How Show Freeze Frame Data Works:

1. OBD2 Scanner Connection: Connect an OBD2 scanner to the vehicle’s OBD2 port, establishing communication with the Engine Control Module (ECM) and other onboard systems.
2. Selecting Service 02 – Show Freeze Frame Data: Navigate through the OBD2 scanner menu to find and select Service 02 – Show Freeze Frame Data.
3. Retrieving Freeze Frame Data: The OBD2 scanner sends a request to the ECM to retrieve the freeze frame data associated with a specific Diagnostic Trouble Code (DTC) that has been stored in the vehicle’s memory.
4. Freeze Frame Data Parameters: The ECM responds by providing freeze frame data, including parameters such as engine RPM, vehicle speed, coolant temperature, fuel trim values, and other relevant sensor readings.
5. Displaying Results: The OBD2 scanner displays the retrieved freeze frame data on its screen. The data may be presented as numerical values, graphical representations, or charts, depending on the capabilities of the scanner.
6. Analysis and Troubleshooting: Technicians analyze the freeze frame data to gain insights into the conditions at the time of the fault. This information aids in troubleshooting, helping to identify the root cause of the issue.
7. Diagnostic Decision-Making: Based on the freeze frame data, technicians make informed decisions regarding the next steps in the diagnostic process. It may involve additional tests, inspections, or component checks related to the observed parameters.

The “Show Freeze Frame Data” service is a valuable diagnostic tool that provides a snapshot of vehicle parameters at the moment a fault occurs. This contextual information enhances the precision of diagnostics and aids technicians in effectively identifying and addressing issues.

Mode/Service 03 (03h) – Show Stored Diagnostic Trouble Codes (DTCs):

The “Show Stored Diagnostic Trouble Codes (DTCs)” service, denoted by Service 03 (03h) in the OBD communication protocol according to SAE J1979 (aligned with ISO 15031), is a diagnostic function that allows an external OBD2 scanner or diagnostic tool to retrieve and display diagnostic trouble codes (DTCs) that have been stored in the vehicle’s Engine Control Module (ECM) or other relevant control modules.

Here’s an explanation of the “Show Stored DTCs” service:

Why Show Stored Diagnostic Trouble Codes (DTCs):

1. Fault Code Retrieval: This service allows technicians and users to retrieve and view diagnostic trouble codes (DTCs) that have been recorded in the vehicle’s memory. DTCs are indications of potential issues within the vehicle’s systems.
2. Identifying Issues: Each DTC corresponds to a specific fault or malfunction in a system or component. Retrieving stored DTCs helps identify the areas where issues have been detected, guiding the diagnostic process.
3. Historical Reference: Stored DTCs provide a historical record of past issues. Even if the “Check Engine” light is not currently illuminated, reviewing stored DTCs can reveal previously encountered problems.

How Show Stored Diagnostic Trouble Codes (DTCs) Works:

1. OBD2 Scanner Connection: Connect an OBD2 scanner to the vehicle’s OBD2 port, establishing communication with the Engine Control Module (ECM) and other relevant control modules.
2. Selecting Service 03 – Show Stored DTCs: Navigate through the OBD2 scanner menu to find and select Service 03 – Show Stored DTCs.
3. Requesting Stored DTCs: The OBD2 scanner sends a request to the ECM and other control modules to retrieve and transmit any stored diagnostic trouble codes.
4. DTC Retrieval: The ECM responds by providing information about the stored DTCs, including the specific codes, their descriptions, and additional data related to the detected faults.
5. Displaying Results: The OBD2 scanner displays the retrieved stored DTCs on its screen. Each DTC is associated with a particular system or component and is typically represented by a alphanumeric code.
6. Interpretation and Analysis: Technicians analyze the retrieved DTCs to understand the nature of the detected issues. Each code provides information about the system or component affected and the type of fault that has been detected.
7. Diagnostic Decision-Making: Based on the identified DTCs, technicians can make informed decisions about the next steps in the diagnostic process. This may involve further testing, inspections, or component checks related to the specific DTCs.
8. Clearing DTCs (Optional): Some diagnostic tools may offer the option to clear or reset stored DTCs after the issues have been addressed and resolved. Clearing DTCs turns off the “Check Engine” light.

The “Show Stored Diagnostic Trouble Codes (DTCs)” service is a fundamental diagnostic tool that allows for the retrieval and analysis of historical fault codes stored in the vehicle’s memory. This information aids in the identification and resolution of past and current issues within the vehicle’s systems.

Mode/Service 04 (04h) – Clear Diagnostic Trouble Codes (DTCs):

The “Clear Diagnostic Trouble Codes (DTCs)” service, denoted by Service 04 (04h) in the OBD communication protocol according to SAE J1979 (aligned with ISO 15031), is a diagnostic function that allows an external OBD2 scanner or diagnostic tool to send a command to the vehicle’s Engine Control Module (ECM) or relevant control modules, instructing them to clear or reset stored diagnostic trouble codes (DTCs).

Here’s an explanation of the “Clear DTCs” service:

Why Clear Diagnostic Trouble Codes (DTCs):

1. Resetting Fault Indicators: Clearing DTCs turns off the “Check Engine” light or other fault indicators on the vehicle’s dashboard. This is particularly useful after resolving the underlying issues that triggered the codes.
2. Verification of Repairs: After addressing and repairing issues that led to the setting of diagnostic trouble codes, technicians use this service to confirm that the problems have been resolved and to verify that no new issues are present.
3. Emission Testing Readiness: In regions where emission testing is required for vehicle inspections, clearing DTCs helps ensure that the vehicle is in a “ready” state for testing, as the presence of certain DTCs may result in a test failure.

How Clear Diagnostic Trouble Codes (DTCs) Works:

1. OBD2 Scanner Connection: Connect an OBD2 scanner to the vehicle’s OBD2 port, establishing communication with the Engine Control Module (ECM) and other relevant control modules.
2. Selecting Service 04 – Clear DTCs: Navigate through the OBD2 scanner menu to find and select Service 04 – Clear DTCs.
3. Confirmation and Authorization: The OBD2 scanner sends a command to the ECM or other control modules, requesting permission to clear stored DTCs. Some systems may require confirmation from the user or technician before proceeding.
4. Clearing DTCs: Once authorized, the ECM or control modules execute the command, clearing or resetting the stored diagnostic trouble codes. This action turns off the “Check Engine” light and other related fault indicators.
5. Verification: After clearing DTCs, technicians can re-scan the vehicle to confirm that no DTCs are currently present. This verification step ensures that the issues triggering the codes have been successfully addressed.
6. Emission Testing Readiness: In some cases, certain drive cycles or conditions may be necessary to complete the readiness monitors for emission testing. Technicians or users may follow specific procedures to ensure the vehicle is in a “ready” state for testing.
7. Documenting Actions: Technicians often document the clearing of DTCs as part of the repair and diagnostic process. This documentation provides a record of the actions taken to address and resolve identified issues.

It’s important to note that clearing DTCs should only be done after addressing and resolving the underlying issues that led to the codes. Simply clearing codes without addressing the root cause may result in recurring problems.

Mode/Service 05 (05h) – Test Results, Oxygen Sensor Monitoring (Non-Continuous Monitors):

The “Test Results, Oxygen Sensor Monitoring (Non-Continuous Monitors)” service, denoted by Service 05 (05h) in the OBD communication protocol according to SAE J1979 (aligned with ISO 15031), is a diagnostic function that allows an external OBD2 scanner or diagnostic tool to request and receive information related to the monitoring and testing of oxygen sensors. This service specifically focuses on non-continuous monitors related to oxygen sensor performance.

Here’s an explanation of the “Test Results, Oxygen Sensor Monitoring (Non-Continuous Monitors)” service:

Why Test Results, Oxygen Sensor Monitoring:

1. Oxygen Sensor Health: Oxygen sensors play a critical role in monitoring and adjusting the air-fuel mixture in the engine. This service provides information about the health and performance of oxygen sensors, which is crucial for efficient engine operation and emissions control.
2. Non-Continuous Monitors: Some vehicle monitors operate intermittently or under specific driving conditions. The service focuses on non-continuous monitors related to oxygen sensors, providing data on their functioning outside of continuous monitoring.

How Test Results, Oxygen Sensor Monitoring Works:

1. OBD2 Scanner Connection: Connect an OBD2 scanner to the vehicle’s OBD2 port, establishing communication with the Engine Control Module (ECM) and other relevant control modules.
2. Selecting Service 05 – Test Results, Oxygen Sensor Monitoring: Navigate through the OBD2 scanner menu to find and select Service 05 – Test Results, Oxygen Sensor Monitoring.
3. Requesting Test Results: The OBD2 scanner sends a request to the ECM, instructing it to provide information about the test results and performance of oxygen sensors, particularly those related to non-continuous monitors.
4. Data Retrieval: The ECM responds by transmitting data related to the test results of oxygen sensors. This data includes readings, measurements, and diagnostic information about the sensors’ performance.
5. Displaying Results: The OBD2 scanner displays the retrieved oxygen sensor test results on its screen. This information may include sensor voltages, response times, and other relevant parameters.
6. Interpretation and Analysis: Technicians interpret the displayed results to assess the health and functionality of the oxygen sensors. Anomalies or deviations from expected values may indicate potential issues with the sensors.
7. Diagnostic Decision-Making: Based on the analysis of the oxygen sensor test results, technicians can make informed decisions regarding further diagnostics or actions. This may involve inspecting sensor wiring, connectors, or the sensors themselves.
8. Addressing Identified Issues: If the test results reveal issues with the oxygen sensors, technicians can take appropriate actions, such as repairing or replacing faulty sensors, to ensure proper engine performance and emissions control.
9. Verification of Repairs: After addressing identified issues, users may re-run the oxygen sensor monitoring service to verify that the repairs were successful and that the sensors are now operating within expected parameters.

The “Test Results, Oxygen Sensor Monitoring (Non-Continuous Monitors)” service provides valuable information about the performance of oxygen sensors, focusing on non-continuous monitors. This aids in maintaining optimal engine efficiency and emissions control.

Mode/Service 06 (06h) – Show Pending Diagnostic Trouble Codes (DTCs):

The “Show Pending Diagnostic Trouble Codes (DTCs)” service, denoted by Service 06 (06h) in the OBD communication protocol according to SAE J1979 (aligned with ISO 15031), is a diagnostic function that allows an external diagnostic tool to retrieve and display diagnostic trouble codes (DTCs) that have been detected by the vehicle’s Engine Control Module (ECM) but have not yet been confirmed during a specific drive cycle.

Here’s an explanation of the “Show Pending DTCs” service:

Why Show Pending DTCs:

1. Early Issue Identification: Pending DTCs are codes that the ECM has detected but hasn’t confirmed as a persistent fault. Accessing these codes helps in identifying potential issues early, allowing for timely diagnosis and repairs.
2. Drive Cycle Confirmation: Pending DTCs are often set during a specific drive cycle. Retrieving these codes provides information about issues that may only occur under certain driving conditions.

How Show Pending DTCs Works:

1. OBD2 Scanner Connection: Connect an OBD2 scanner to the vehicle’s OBD2 port, establishing communication with the ECM and other onboard systems.
2. Selecting Service 06 – Show Pending DTCs: Navigate through the OBD2 scanner menu to find and select Service 06 – Show Pending DTCs.
3. Requesting Pending DTCs: The OBD2 scanner sends a request to the ECM to retrieve any pending diagnostic trouble codes that have been detected but not yet confirmed.
4. Retrieval of Pending DTCs: The ECM responds to the request by providing information about pending diagnostic trouble codes. This includes the code itself, as well as additional data related to the specific fault.
5. Displaying Results: The OBD2 scanner displays the retrieved pending DTCs on its screen. Users can review the codes and associated information, helping in the diagnostic process.
6. Interpretation and Analysis: Technicians interpret the pending DTCs to understand the nature of the detected issues. This analysis guides further diagnostic procedures and necessary repairs.
7. Addressing Issues: Based on the identified pending DTCs, technicians can take appropriate actions to address the issues. This may involve component testing, further diagnostics, or repairs to resolve the detected faults.
8. Verification of Repairs: After addressing the identified issues, users can re-run the “Show Pending DTCs” service to confirm that the pending codes have been resolved and are no longer present.

The “Show Pending DTCs” service provides a snapshot of potential issues detected by the vehicle’s ECM during a specific drive cycle. Accessing these pending codes helps in early diagnosis, ensuring that emerging problems are identified and addressed before they escalate.

Mode/Service 07 (07h) – Show Onboard Systems or Components:

The “Show Onboard Systems or Components” service, denoted by Service 07 (07h) in the OBD communication protocol according to SAE J1979 (aligned with ISO 15031), is a diagnostic function that allows an external OBD2 scanner or diagnostic tool to retrieve and display information about the status and availability of various onboard systems or components within a vehicle.

Here’s an explanation of the “Show Onboard Systems or Components” service:

Why Show Onboard Systems or Components:

1. System Status Check: This service enables users, technicians, or diagnostic tools to check the status of different onboard systems or components. It provides an overview of whether these systems are functioning properly.
2. Comprehensive Diagnostic Information: By displaying information about various systems, the service aids in comprehensive diagnostics, allowing users to identify potential issues in specific vehicle systems.
3. Maintenance Planning: Users can use the information to plan maintenance activities, ensuring that all critical systems are in good working condition.

How Show Onboard Systems or Components Works:

1. OBD2 Scanner Connection: Connect an OBD2 scanner to the vehicle’s OBD2 port, establishing communication with the Engine Control Module (ECM) and other onboard control modules.
2. Selecting Service 07 – Show Onboard Systems or Components: Navigate through the OBD2 scanner menu to find and select Service 07 – Show Onboard Systems or Components.
3. Requesting System Information: The OBD2 scanner sends a request to the ECM and other relevant control modules, instructing them to provide information about the status and availability of various onboard systems or components.
4. Data Retrieval: The ECM and control modules respond by transmitting data related to the status of different systems. This data may include information about the engine, transmission, ABS (Anti-lock Braking System), airbags, and other vehicle systems.
5. Displaying Results: The OBD2 scanner displays the retrieved information on its screen. The data may be presented in a menu format, allowing users to navigate through different systems and view specific details about each one.
6. System Status Indicators: The displayed information may include indicators or flags for each system, indicating whether they are operating normally or if there are issues or fault codes present.
7. Interpretation and Analysis: Technicians interpret the displayed information to assess the overall health and status of various onboard systems. Anomalies or fault codes may guide further diagnostics.
8. Diagnostic Decision-Making: Based on the analysis of system status information, technicians can make informed decisions regarding the need for additional diagnostics, inspections, or maintenance actions.
9. Maintenance Planning: Users can use the information gathered from this service to plan maintenance activities, addressing potential issues before they escalate and ensuring the vehicle’s overall reliability.

The “Show Onboard Systems or Components” service provides a comprehensive overview of the status and availability of various vehicle systems. It is a valuable tool for both routine maintenance planning and in-depth diagnostics, helping users and technicians ensure the proper functioning of critical components within the vehicle.

Mode/Service 08 (08h) – Control Operation of Onboard Systems or Components:

The “Control Operation of Onboard Systems or Components” service, denoted by Service 08 (08h) in the OBD communication protocol according to SAE J1979 (aligned with ISO 15031), is a diagnostic function that allows an external OBD2 scanner or diagnostic tool to send commands to the vehicle’s Engine Control Module (ECM) or relevant control modules, instructing them to control or test the operation of specific onboard systems or components.

Here’s an explanation of the “Control Operation of Onboard Systems or Components” service:

Why Control Operation of Onboard Systems or Components:

1. Functional Testing: This service enables technicians or users to perform functional tests on specific vehicle systems or components. It is valuable for verifying the operational status of different parts of the vehicle.
2. Actuator Testing: Users can use this service to send commands that actuate or control certain components, such as solenoids, relays, or actuators, for testing and diagnostic purposes.
3. Confirmation of Repairs: After making repairs or replacements to a particular system or component, technicians can use this service to confirm that the repairs were successful by observing the response to control commands.

How Control Operation of Onboard Systems or Components Works:

1. OBD2 Scanner Connection: Connect an OBD2 scanner to the vehicle’s OBD2 port, establishing communication with the Engine Control Module (ECM) and other relevant control modules.
2. Selecting Service 08 – Control Operation: Navigate through the OBD2 scanner menu to find and select Service 08 – Control Operation of Onboard Systems or Components.
3. Selecting Target System or Component: The user or technician chooses the specific onboard system or component they want to control or test. The options may include actuators, solenoids, relays, or other relevant components.
4. Sending Control Commands: The OBD2 scanner sends commands to the ECM or control modules, instructing them to control or actuate the selected system or component as specified.
5. Observing System Response: Technicians observe the response of the targeted system or component to the control commands. This may involve visual inspections, listening for sounds, or using sensors to monitor changes in performance.
6. Interpretation and Analysis: Based on the observed response, technicians interpret the results to assess the functionality and condition of the controlled system or component. Anomalies or unexpected behavior may indicate issues that require further investigation.
7. Confirmation of Repairs: If the service is used after making repairs or replacements, technicians can use the results to confirm that the targeted system or component is now operating within expected parameters.
8. Documentation: Technicians may document the results of the control operation service as part of the diagnostic and repair process. This documentation serves as a record of the tests performed and their outcomes.

It’s important to note that the “Control Operation of Onboard Systems or Components” service should be used with caution, and users should follow manufacturer guidelines to avoid unintended consequences or damage to the vehicle. This service is typically employed by experienced technicians during diagnostics and testing procedures.

Mode/Service 09 (09h) – Request Vehicle Information:

The “Request Vehicle Information” service, denoted by Service 09 (09h) in the OBD communication protocol according to SAE J1979 (aligned with ISO 15031), is a diagnostic function that allows an external OBD2 scanner or diagnostic tool to request and receive essential information about the vehicle. This service provides details such as the Vehicle Identification Number (VIN), calibration IDs, and other information related to the vehicle’s identification and specifications.

Here’s an explanation of the “Request Vehicle Information” service:

Why Request Vehicle Information:

1. Vehicle Identification: This service provides vital information for identifying the vehicle, including the unique Vehicle Identification Number (VIN). The VIN is a crucial identifier for various purposes, such as registration and insurance.
2. Calibration IDs: The service retrieves calibration IDs, which are specific identifiers for the software and calibration levels installed in the vehicle’s Engine Control Module (ECM) and other control modules. This information is valuable for ensuring compatibility during diagnostic procedures and software updates.
3. Specifications: The service may provide additional information about the vehicle, such as the make, model, year, and other specifications. This information is useful for diagnostic and documentation purposes.

How Request Vehicle Information Works:

1. OBD2 Scanner Connection: Connect an OBD2 scanner to the vehicle’s OBD2 port, establishing communication with the Engine Control Module (ECM) and other relevant control modules.
2. Selecting Service 09 – Request Vehicle Information: Navigate through the OBD2 scanner menu to find and select Service 09 – Request Vehicle Information.
3. Sending Request: The OBD2 scanner sends a request to the ECM and other control modules, asking for essential vehicle information, including the VIN and calibration IDs.
4. Data Retrieval: The ECM and control modules respond by transmitting the requested vehicle information to the OBD2 scanner. This data may include the VIN, calibration IDs, and other relevant details.
5. Displaying Results: The OBD2 scanner displays the retrieved vehicle information on its screen. The information may be presented in a structured format, allowing users to easily read and verify the details.
6. Verification: Users can verify the displayed information to ensure accuracy and completeness. The VIN, in particular, is cross-checked to confirm its accuracy against the physical VIN on the vehicle.
7. Documentation: Technicians or users may document the retrieved vehicle information as part of diagnostic records or for compliance with regulatory requirements.
8. Compatibility Check: Calibration IDs retrieved through this service may be compared with the latest available updates to check for compatibility. This information is essential for ensuring accurate diagnostics and updating vehicle software.

The “Request Vehicle Information” service provides essential details about the vehicle, including the VIN, calibration IDs, and other specifications. This information is valuable for identification, diagnostics, and ensuring compatibility during maintenance and software updates.

Summary

The comprehensive guide on “Using an OBD2 Scanner for Troubleshooting Vehicle Issues” equips both certified automotive technicians and car enthusiasts with essential knowledge for efficient diagnostics. Covering the fundamentals of OBD2 scanners, the guide explores the critical functions, such as reading Diagnostic Trouble Codes (DTCs), live data monitoring, and clearing fault codes. It delves into the significance of Freeze Frame Data, Oxygen Sensor Testing, and the Mode 6 Diagnostics feature, providing insights into advanced troubleshooting techniques. The guide also emphasizes the importance of Onboard Monitor Testing and Vehicle Information Retrieval for emission control and precise diagnostics. Concluding with the significance of Component Testing, the guide empowers users to leverage OBD2 scanners effectively, enhancing their ability to identify, address, and prevent vehicle issues with precision.