Car Diagnostic Codes: What They Mean?

When working with auto maintenance, you’re going to want to utilize OBDII scanners and adapters. 

These are the options that professionals use to figure out what is wrong with a vehicle. 

Without these devices, mechanics would have to apply a trial and error type of diagnostics to figure out what is wrong with a car. 

In the past, that was the main thing that professionals had to do. However, today, with modern technology, you can use a handheld adapter to get information overall. 

When you look into OBD solutions, you’ll find that diagnostic codes can be somewhat confusing overall.

How OBD Scanners Work

Before getting into what the codes that come from scanners mean, and how to read them, you’ll need to know how the devices work. 

Scanners attach to the on-board computer systems that are found in cars, and delivers data about the vehicle overall. 

Car manufacturers after the mid-1980s all started to work with computer systems, and elements that control the way a vehicle moves forward. Everything is controlled by software today.

OBD stands for on board diagnostics, and it’s one of the main options that you’ll find in modern garages that fix cars. 

You can purchase a scanner, application, or even software for your laptop to get familiar with the issues that your car may have. 

The information relays from the on board computing and spits out a code that you can use to figure out what is wrong with the overall system. 

It’s like asking your car what’s wrong, and getting an exact answer.

Just The Codes

When you purchase a OBDII option, you’ll find that you will get data that is in the form of a code. 

In the most basic of solutions, you’ll find that you will get a simplified code solution, and nothing more. However, higher end solutions will give you an overall code, and definition. 

Not only that, you’ll be able to look up codes and figure out what you can do to fix the issue and repair everything correctly.

Assuming you were to purchase a lower cost solution, you’ll find that you will receive just the codes, which usually start with the letter P and the number 0 (P0). 

These are generic overall, and are often known as manufacturer codes. In that regards, you will need to look for a repair manual that is specific to your make and model. 

Without a repair manual, your proprietary codes will not be easy to figure out. You’ll need to know what they mean.

Getting The Manuals

There are two choices that you have in regards to figuring out the codes for your car’s problems. You will need to purchase a manual for your car’s make, year, and even specialty build. 

There are full manuals found online, and there are many options found through auction sites, and even from the manufacturer themselves. 

Finding the manual is going to be critical if you are getting generic manufacturer codes from your diagnostic scanner.

If you find aftermarket scanners that are not from the manufacturer themselves, you may be able to get tutorials on how to fix the problems with the codes. 

These are often inexpensive, and are from third-party solutions.

Example of Codes and What To Consider

Each diagnostic code is meant to give you information about what is wrong with the vehicle. 

You’ll find that there are several examples that you can work with, but the following can be one of the common issues.

Let’s say you receive the code P0340 or something similar. That is going to tell you that there’s something wrong with the powertrain. 

The letter P in the generic codes means that the powertrain issue is the big issue. There are other digits that are generic, such as B, C, and U. 

Each of these first digits can refer to the body, chassis, and even the network overall.

The second digit can mean a manufacturer code, and the third digit can be specific to the area that the problem exists. 

Not only that, you’ll find that the last two digits can be a fault code that is in regards to your specific make and model car.

The Two Types of Codes You Need To Know

Moving forward, you’ll find that there are two major codes that you will need to know about in consideration of OBD solutions.

It’s imperative that you understand how these work out, otherwise you will not be able to apply a fix.

Diagnostic Code Type 1

The first type of solution is in regards to emissions, driving cycles, and freeze element from the engine to the scanner. 

This will give you an idea as to what the bigger picture may be.

Diagnostic Code Type 2

The second of the diagnostic codes is in regards to emissions that are not necessarily related to pollution.

It also is an issue that is in regards to failing cycles, check engine cycles, and failed cycles through the turn over of the engine.

Categories To Consider

As mentioned above, the code structure that you will find can range from P0100 to P0999. 

These examples are related to common category elements. 

The following elements are common with the code categories between these numbers and examples:

• Fuel Metering
• Air Metering
• Ignition Systems
• Engine Misfire
• Auxiliary Emissions
• Vehicle Speed
• Computer Output
• Transmission Codes

These categories will start with a P0 and then range from 100 to 999 overall. These are trouble codes, aka DTC. 

These are common categories with the digits and code list that you may see often. However, you’ll have to double check with a common OBD code list and what they mean.

Common code lists are found online, with information on each and every code you may see. 

Cars made after 1996 have common options that you can learn about when you purchase an OBDII scanner and then start using the appropriate OBD software. 

Overall, this is not a difficult thing to use or manage, however, you’ll need to familiarize yourself with the code structure, the code meanings, and manufacturer specific elements for fixes that you may need to apply.