Editing On-board diagnostics (section)

== Applications ==

Various tools are available that plug into the OBD connector to access OBD functions. These range from simple generic consumer level tools to highly sophisticated [[Original equipment manufacturer|OEM]] dealership tools to vehicle telematic devices.

=== Hand-held scan tools ===
[[File:Autoboss v-30.png|thumb|Multi-brand vehicle diagnostics system handheld Autoboss V-30 with adapters for connectors of several vehicle manufacturers.<ref>{{cite web|title=Autoboss 30 Diagnostic Coverage List|url=http://autobossuk.co.uk/uploads/documents/53.pdf}}</ref>]]

A range of rugged hand-held scan tools is available.

* Simple fault code readers/reset tools are mostly aimed at the consumer level.
* Professional hand-held scan tools may possess more advanced functions
** Access more advanced diagnostics
** Set manufacturer- or vehicle-specific ECU parameters
** Access and control other control units, such as air bag or ABS
** Real-time monitoring or graphing of engine parameters to facilitate diagnosis or tuning

=== Mobile device-based tools and analysis ===

Mobile device applications allow mobile devices such as cell phones and tablets to display and manipulate the OBD-II data accessed via [[USB]] adaptor cables or [[Bluetooth]] adapters plugged into the car's OBD II connector. Newer devices on the market are equipped with GPS sensors and the ability to transmit vehicle location and diagnostics data over a cellular network. Modern OBD-II devices can therefore nowadays be used to for example locate vehicles, monitor driving behavior in addition to reading Diagnostics Trouble Codes (DTC). Even more advanced devices allow users to reset engine DTC codes, effectively turning off engine lights in the dashboard; however, resetting the codes does not address the underlying issues and can in worst-case scenarios even lead to engine breakage where the source issue is serious and left unattended for long periods.<ref>{{Cite web|title=Intro to OBD-II vehicle diagnostics and GPS tracking|url=https://eu.tramigo.store/blog-guides/intro-to-obd-2-vehicle-diagnostics-and-gps-tracking/|website=OBD By Tramigo}}</ref><ref>{{Cite web|title=Driving Behaviour Identification based on OBD Speed and GPS Data Analysis|url=https://www.researchgate.net/publication/348910319|website=Researchgate}}</ref>

=== OBD-II Software ===
An OBD-II software package when installed in a computer ([[Microsoft Windows|Windows]], [[MacOS|Mac]], or [[Linux]]) can help diagnose the onboard system, read and erase DTCs, turn off MIL, show real-time data, and measure vehicle fuel economy.<ref>{{Cite web|title=OBD Software – Elm Electronics|url=https://www.elmelectronics.com/help/obd/software/|access-date=2021-11-22|language=en-US}}</ref>

To use OBD-II software, one needs to have an OBD-II adapter (commonly using [[Bluetooth]], [[Wi-Fi]] or [[USB]])<ref>{{Cite web|title=How to choose an OBD II adapter: Wi-Fi or Bluetooth – inCarDoc|url=https://incardoc.com/CarDoctorPortal/en-us/article/how-to-choose-an-obd-ii-adapter-wi-fi-or-bluetooth/|access-date=2021-11-22|website=CarDoctorPortal|language=en}}</ref> plugged in the OBD-II port to enable the vehicle to connect with the computer where the software is installed.<ref>{{Cite web|last=Miller|first=Tim|date=October 31, 2021|title=How Does OBD2 Software Work?|url=https://www.obdadvisor.com/top-obd2-software-packages-for-pc/#How_does_OBD2_car_diagnostic_software_work|website=OBD Advisor}}</ref>

=== PC-based scan tools and analysis platforms ===
[[File:Obd usb kkl interface.jpg|thumb|Typical simple USB KKL Diagnostic Interface without protocol logic for signal level adjustment.]]

A PC-based OBD analysis tool that converts the OBD-II signals to serial data (USB or serial port) standard to PCs or Macs. The software then decodes the received data to a visual display. Many popular interfaces are based on the [[ELM327]] or STN<ref>{{cite web |url=https://www.obdsol.com/solutions/chips/ |title=OBD Interpreter ICs |website=OBD Solutions |access-date=2024-06-02}}</ref> OBD Interpreter ICs, both of which read all five generic OBD-II protocols. Some adapters now use the J2534 API allowing them to access OBD-II Protocols for both cars and trucks.

In addition to the functions of a hand-held scan tool, the PC-based tools generally offer:
* Large storage capacity for data logging and other functions
* Higher resolution screen than handheld tools
* The ability to use multiple software programs adding flexibility
* The identification and clearance of fault code
* Data shown by intuitive graphs and charts

The extent that a PC tool may access manufacturer or vehicle-specific ECU diagnostics varies between software products<ref>{{Cite web|last=Miller|first=Tim|title=OBD2 Diagnostic Software for Laptop/PC|url=https://www.obdadvisor.com/top-obd2-software-packages-for-pc/|website=OBD Advisor|date=February 12, 2019}}</ref> as it does between hand-held scanners.
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=== Data loggers ===
[[File:Texa obd-log.png|thumb|TEXA OBD log. Small data logger with the possibility to read out the data later on PC via USB.]]

[[Data logger]]s are designed to capture vehicle data while the vehicle is in normal operation, for later analysis.

Data logging uses include:
* Engine and vehicle monitoring under normal operation, for diagnosis or tuning.
* Some US auto insurance companies offer reduced premiums if OBD-II vehicle data loggers<ref>{{Cite web|title=OBD2 Data Logger – Easily Record & Visualize Your Car Data|url=https://www.csselectronics.com/pages/obd2-data-logger-sd-memory-convert|access-date=2021-11-22|website=CSS Electronics|language=en}}</ref><ref>{{Cite web|title=Home • IOSiX|url=https://iosix.com/|access-date=2021-11-22|website=IOSiX|language=en-US}}</ref> or cameras are installed – and if the driver's behaviour meets requirements. This is a form of [[auto insurance risk selection]]
* Monitoring of driver behaviour by [[fleet vehicle]] operators.

Analysis of vehicle [[flight recorder|black box]] data may be performed periodically, automatically transmitted wirelessly to a third party or retrieved for forensic analysis after an event such as an accident, traffic infringement or mechanical fault.

===Emission testing===

In the United States, many states now use OBD-II testing instead of tailpipe testing in OBD-II compliant vehicles (1996 and newer). Since OBD-II stores trouble codes for emissions equipment, the testing computer can query the vehicle's onboard computer and verify there are no emission related trouble codes and that the vehicle is in compliance with emission standards for the model year it was manufactured.

In the Netherlands, 2006 and later vehicles get a yearly EOBD emission check.<ref>{{Cite web|title=Periodic motor vehicle test (APK)|url=https://business.gov.nl/regulation/periodic-motor-vehicle-test-apk/|access-date=2021-11-22|website=business.gov.nl|language=en}}</ref>

=== Driver's supplementary vehicle instrumentation ===

'''Driver's supplementary vehicle instrumentation''' is instrumentation installed in a vehicle in addition to that provided by the vehicle manufacturer and intended for display to the driver during normal operation. This is opposed to scanners used primarily for [[active fault]] diagnosis, tuning, or hidden data logging.

Auto enthusiasts have traditionally installed additional gauges such as manifold vacuum, battery current etc. The OBD standard interface has enabled a new generation of enthusiast instrumentation accessing the full range of vehicle data used for diagnostics, and derived data such as instantaneous fuel economy.

Instrumentation may take the form of dedicated [[trip computer]]s,<ref>[[OBDuino]] open source OBD trip computer</ref> [[carputer]] or interfaces to [[Personal digital assistant|PDAs]],<ref>{{Cite web|date=2020-12-15|title=Advantages and Disadvantages of Personal digital assistant|url=https://www.geeksforgeeks.org/advantages-and-disadvantages-of-personal-digital-assistant/|access-date=2021-11-22|website=GeeksforGeeks|language=en-us}}</ref> smartphones, or a [[Garmin]] navigation unit.

As a carputer is essentially a PC, the same software could be loaded as for PC-based scan tools and vice versa, so the distinction is only in the reason for use of the software.

These enthusiast systems may also include some functionality similar to the other scan tools.

=== Vehicle telematics ===

OBD II information is commonly used by vehicle telematics devices that perform fleet tracking, monitor fuel efficiency, prevent unsafe driving, as well as for remote diagnostics and by [[pay-as-you-drive]] insurance.

Although originally not intended for the above purposes, commonly supported OBD II data such as vehicle speed, RPM, and fuel level allow GPS-based fleet tracking devices to monitor vehicle idling times, speeding, and over-revving. By monitoring OBD II DTCs a company can know immediately if one of its vehicles has an engine problem and by interpreting the code the nature of the problem. It can be used to detect reckless driving in real time based on the sensor data provided through the OBD port.<ref>{{Cite journal|last=Shashika|first=Muramudalige|date=24 August 2015|title=Cloud-based driver monitoring and vehicle diagnostic with OBD2 telematics|url=https://popularapk.com/wp-content/uploads/2022/02/CloudBasedDriverMonitoringOBD2.pdf|journal=IEEE International Conference on Electro/Information Technology|via=Academia.edu}}</ref> This detection is done by adding a complex events processor (CEP) to the backend and on the client's interface. OBD II is also monitored to block mobile phones when driving and to record trip data for insurance purposes.<ref>{{Cite web|title=What is Vehicle Telematics? Definition and FAQs {{!}} OmniSci|url=https://www.omnisci.com/technical-glossary/vehicle-telematics|access-date=2021-11-22|website=www.omnisci.com}}</ref>