Generic Codes

Generic OBD2 codes are standardized codes that apply to all cars that are OBD2 compliant, regardless of the make or model. 

Our collection of articles on this page provides a wealth of information about these codes, going beyond just an explanation of what they mean. We analyze each code in detail, providing technical explanations, common causes, symptoms to look out for, and recommended solutions for each issue.

So why wait? Start exploring now!

In a hurry? Quickly jump to the code you're facing:

U0034: Vehicle Communication Bus A (-) Low

By OBD Codex / January 14, 2024

Is the U0034 code causing communication issues in your vehicle? Read on to learn how to deal with this communication network problem and get your vehicle back on the road.

U0035: Vehicle Communication Bus A (-) High

By OBD Codex / January 20, 2024

Is the U0035 code causing communication issues in your vehicle? Read on to learn how to deal with this communication network problem and get your vehicle back on the road.

U0036: Vehicle Communication Bus A (-) shorted to Bus A (+)

By OBD Codex / January 21, 2024

Is the U0036 code causing communication issues in your vehicle? Read on to learn how to deal with this communication network problem and get your vehicle back on the road.

U0037: Vehicle Communication Bus B

By OBD Codex / February 14, 2024

Is the U0037 code causing communication issues in your vehicle? Read on to learn how to deal with this communication network problem and get your vehicle back on the road.

U0038: Vehicle Communication Bus B Performance

By OBD Codex / January 14, 2024

Is the U0038 code causing communication issues in your vehicle? Read on to learn how to deal with this communication network problem and get your vehicle back on the road.

U0039: Vehicle Communication Bus B (+) Open

By OBD Codex / January 14, 2024

Is the U0039 code causing communication issues in your vehicle? Read on to learn how to deal with this communication network problem and get your vehicle back on the road.

U003A: ISO/SAE Reserved

By OBD Codex / February 09, 2024

The U003A code is a generic ISO/SAE Reserved code that may appear in your vehicle's diagnostic system. Read on to learn more about it and what you should do to deal with it.

U003B: ISO/SAE Reserved

By OBD Codex / February 10, 2024

The U003B code is a generic ISO/SAE Reserved code that may appear in your vehicle's diagnostic system. Read on to learn more about it and what you should do to deal with it.

U003C: ISO/SAE Reserved

By OBD Codex / February 05, 2024

The U003C code is a generic ISO/SAE Reserved code that may appear in your vehicle's diagnostic system. Read on to learn more about it and what you should do to deal with it.

U003D: ISO/SAE Reserved

By OBD Codex / January 30, 2024

The U003D code is a generic ISO/SAE Reserved code that may appear in your vehicle's diagnostic system. Read on to learn more about it and what you should do to deal with it.