Licensable OBD II Protocol Stack Source Code

OBD Experts can provide you with ready-to-use OBD II software source code to get you up and running quickly. We offer a simple one-time licensing fee model so once licensed  it can be used in all of your organisation’s current and future products without any further payment necessary.

Our OBD II firmware is organised into a simple hierarchy of software layers called a protocol stack. The OBD II protocol stack includes the source code for all OBD II protocols (CAN 15765-4, KWP2000, ISO 9141, J1850 PWM and J1850 VPW). The truck protocol J1939 is also available at additional cost. The software includes a user API and a demonstration file as well as distinct OBD and Hardware Abstraction Layers. In addition to the OBD II Software you also receive comprehensive documentation on how to get started with your development and one year of off-site support.

Try before you buy – We have demonstration boards available so you can connect to as many cars as you want to see it working.

OBD Experts licenses software to some of the largest telematics companies in the world and our software is at the heart of hundreds of thousands of telematics devices. Contact to find out more.

Telematics Software for license
  • Skip years of development
  • Adaptable – Hardware and Software
  • Expert Support
  • Ongoing Updates
  • In all your products on all platforms – Forever
  • For Linux, RTOS and non-RTOS environments
OBD II Software Stack
  • ISO 9141-2
  • KWP 2000-4
  • SAE J1850 PWM (Ford SCP)
  • SAE J1850 VPW (GM Class 2)
  • ISO 15765-4 (CAN 11-bit & 29-bit)
  • J1939 (at additional cost)
OBD Software for STM32F0, STM32F1, STM32F2, STM32F3, STM32F4 and PIC32 series
  • STM32F0 series
  • STM32F1 series
  • STM32F2 series
  • STM32F3 series
  • STM32F4 series
  • PIC32 series
  • We can guide you on how to port it to a new processor or we can port it for you


OBD II data like VIN, Speed, RPM, and Fuel Level can make your Telematics product stand out from the crowd.


The Fuel Level can be a very lucrative parameter for car rental companies. It can also be used for tracking fleets and smart-phone based applications. Fuel level is supported on 52% of cars in North America manufactured after 1996 (86% of cars since 2010).


The Vehicle Identification Number (VIN) is a unique number assigned to every car. The VIN can be decoded to determine vehicle make, model, year, engine size, and more. VIN is supported on 91% of cars in North America manufactured after 1996 (99% of cars since 2010).

Vehicle Speed

Vehicle speed is one of the most fundamental pieces of OBD II data for most telematics suppliers. It can be used to monitor driving and create a running odometer. Speed is supported on all cars in North America manufactured after 1996.

Engine RPM

The Engine revolutions per minute can be used to determine if the car is running and to monitor driving behavior. When combined with the vehicle speed, RPM can detect if a vehicle has been left idling. RPM is supported on all cars in North America manufactured after 1996.


The Malfunction Indicator Lamp (MIL) is illuminated upon detection of a problem with the engine. If the MIL is illuminated this means that there is an error number, called a Diagnostic Trouble Code, stored in the on-board engine computer. Use OBD II to read the DTC code and diagnose the problem. MIL status and DTCs are supported on all cars in North America manufactured after 1996.

Engine Coolant Temperature

This is one of many useful OBD II parameters when it comes to monitoring the health of your car or fleet. Engine Coolant Temperature is supported on all cars in North America manufactured after 1996.

Frequently Asked Questions

Still have questions?

When you purchase the complete OBD II Protocol Stack you will receive the source code for all the OBD II protocols. The source files are written in C and organized with a layer of abstraction to the hardware-specific code so that porting of the code to alternative hardware platforms is kept simple. Currently the design is built and tested using an STM32F103 high density ARM Cortex chip so all the actual calls to this chip and the STM32’s library code are provided too. On top of the stack sits a simple API that attempts to connect to one of the protocols, and if successful loops through a file requesting the desired modes and PIDs from the ECU(s).

When you purchase the OBD II Protocol Stack you will be required to sign an agreement stating you will not sell it to any 3rd party, however, you will be able to use it freely – including all modifications – in your company products.

You will not only receive the source code (written entirely in C) but you will also receive comprehensive documentation on how to get started with your development. You also get direct access to our engineers by phone and email, as well as entry to our on-line support page.

All our licences come with off-site support. This is phone and email support for any question that your engineers may have about how the software works, porting, or even general questions about OBD II. There is also a support page on our website that you may access using a password. During your support period you will be notified of bug-fixes if any operational bugs are reported in the software by any of our other clients.

The OBD II protocol stack is usually licensed for a one-off perpetuity fee. The licence includes off-site support. We can also provide monthly payment licences on the source code on a case-by-case basis. Contact us for more information.

Our software is undergoing constant testing and not just by us, but also due to the fact it is in daily use by our customers on hundreds of thousands of vehicles. Every week we test approximately 30 vehicles. We try to cover all Year/Make/Model/Engine combinations. With new model years coming all the time this is a continuous task. As the software is coded to the official J1979 standard it does not change much. If we ever add a new feature then a comprehensive verification and validation process is performed. We first test our code on the bench with a selection of OBD II simulators  and then on a range of actual vehicles. We value customer satisfaction and the only time we have seen a communication problem is when there has been a fault on the vehicle. This is why OBD Experts are the industry leaders in OBD II firmware.

The answer is all OBD II compliant cars. OBD II (J1979) is a standard that all manufacturers of vehicles with emissions have to comply with. OBD Experts software works on all vehicles since 1996 in North America and in Europe then it’s all petrol cars since 2001 and all diesel cars since 2004. So is works on GM, Ford, Honda, Chrysler, Toyota, RAM, Jeep, Subaru, Kia, Hyundai, Mitsubishi, Mercedes, Jaguar, Landrover, Volvo, Fiat, Peugeot, Renault, Citroen, Ferrari, BMW, VW etc. etc. Only cars with no emissions i.e. fully electric cars do not need to comply with the J1979 standard and so do not often support OBD II.

Safe & Secure

Our telematics software is currently deployed in thousands of devices in the USA, Europe and Asia. It is the most reliable solution on the market today.

Fast Delivery

You can be up and running in a matter of days with our well documented and easily adaptable telematics software.

24/7 Support

OBD Experts’ software is fully supported by your own dedicated expert engineer who is available for you anytime you need a hand.