Your Cart()
- Free US Shipping on orders $10+
                        - Free International Shipping on orders $50+
                        - 7-Day Return Guarantee
                        - 12-Month Warranty
- Free US Shipping on orders $20+
- Free International Shipping on orders $50+
- 7-Day Return Guarantee
- 12-Month Warranty

Total Saving

ShippingCalculated at next step

Please Apply Your Coupon Code at Checkout for the Discount. Please Apply Your Coupon Code at Checkout for the Discount.

How to Interpret OBD2 Codes

You’ve purchased your OBD2 Monitor and you’ve installed the vehicle monitor. You’ve been driving around and on your app, you’re receiving codes from the OBD2 Monitor. How can you tell what’s wrong or what needs to be fixed? Learning more about the different Diagnostic Trouble Codes(DTC) will definitely prove to be helpful as you go forward. 


How does OBDII Monitor Work?

Once connected to your car, your OBDII monitor will run diagnostics, regularly reviewing the different systems to find errors or to let you know that everything is okay. These systems are integral parts of your vehicle, and it’s very important that they are running properly for the whole car to work. These systems include your fuel management, O2 sensors, and electrical issues.

The monitor test result provides the status of each system. Much like when you were in school, you want a passing score. 


How to Read OBDII Codes

person diagnosing car problems

Many OBD2 monitors will provide codes that require you to know abbreviations for specific systems. 

  • P for Powertrain which means the engine, transmission, emissions, and ignition to name a few. The codes associated with P is the largest set of codes. 

  • B for Body includes items such as power seating and airbags.

  • C for Chassis which covers the anti-lock braking system (or ABS), axles, and brake fluid.

  • U is undefined, meaning that any other aspect of the car is going to be found in this system.

Once you have that down, you have to know the numbers that apply to the subsystem and then the code that tells you what the specific problem is. 

If you don’t know these codes off the top of your head, you’ll have to spend time googling to help you understand what the issue is. For example, your OBD2 scanner indicates a code P0402. This has to do with the exhaust recirculation system. But in order to start fixing the issue, you will need to go into forums and plenty of threads to learn more about what to fix.

Luckily, we built a website about all Diagnostic Trouble Codes and their possible symptoms, causes, and description. Some articles also provide possible fixes you can do yourself. Feel free to check it out HERE!


What to do with the OBD2 Codes

Understanding the code reader and engine codes may take time to decipher or require that you go directly to a mechanic or auto body shop to get help. 

Luckily, ZUS Smart Vehicle Health Monitor doesn’t require a decoder to determine what the issues are. You hit ‘scan’ on your app and Nonda’s OBDII monitor runs through all the systems. If there is an issue, you are notified of exactly what the problem is.

man holding phone with car health app

Once you have identified the issue, it becomes easy to determine what to do. For some problems, it’s as easy as heading to the local gas station to add some air in the tires of your vehicle. You may have to go to the local auto body shop to get new light bulbs to replace your headlights. 

Other big issues will require the expertise of your local mechanic to fix. You won’t lose time at the mechanic shop waiting for them to diagnose the issues in between changing the oil or fixing other people’s cars. You can call and make your appointment knowing exactly what needs to be fixed.

If you want to know your car better and feel more at ease to recognize issues, reading the OBDII monitor codes will tell you where there may be issues. Or download the ZUS app to save you more time in diagnosing minor issues. 


List of Most Common OBD2 Codes

Here is a list of common OBD2 Codes (DTC Codes) with possible symptoms, causes and a guide of DIY diagnosis/Fixes. Feel free to check them out! And if you cannot find your code here, use the Search Bar to do further research.

P0455 – Evaporative Emission Control System Leak Detected Gross Leak

P0442 – Evaporative Emission Control System Leak Detected Small Leak

P0700 – Transmission Control System Malfunction

P0456 – EVAP Control System Leak Detected Very Small Leak

P0102 – Mass or Volume Air Flow Circuit Low Input

P0446 – Multiple Displacement System Rationality Bank 2

P0420 – Catalyst System Efficiency Below Threshold Bank 1




Leave a comment