Diagnostic Trouble Codes (DTC): What Are They?

Understanding your vehicle’s Diagnostic Trouble Codes (DTC) is an important part of maintaining its performance and longevity.

Here, we’ll break down what DTCs are, how they work, and why knowing them can save you both time and money.

Understanding Diagnostic Trouble Codes (DTC)

DTCs are codes generated by your vehicle’s Onboard Diagnostics (OBD) system when something goes wrong. These codes help pinpoint exactly where the issue lies.

The OBD system, now a standard in most vehicles, monitors various aspects of the vehicle’s performance. When an issue arises, the system detects it and triggers a DTC (Diagnostic Trouble Code), which can be read by yourself, or a vehicle service expert, using a special scanner.

Tools Required to Read DTCs

To read DTCs, you’ll need an OBD-II scanner. These tools plug into the vehicle’s OBD-II port, typically located under the dashboard.

There are also mobile apps and other digital devices that can interpret the codes for you.

Structure of DTCs

A DTC is made up of five characters, each with its own meaning:

• The first character identifies the general system, such as powertrain or chassis.
• The second digit indicates if the code is generic or manufacturer-specific.
• The remaining digits provide further details on the problem.

Step-by-step Process to Find and Read DTCs

• Connect the scanner to the OBD-II port.
• Turn on the vehicle’s ignition, but don’t start the engine.
• Follow the scanner’s instructions to read the codes.
• The scanner will display the codes, which you can then interpret using a code guide.

Common Mistakes to Avoid

A common mistake is misinterpreting the codes — each code requires a proper understanding of what system is affected and how to address it.

Another issue is clearing codes prematurely, which might hide the problem without fixing it.

Common DTCs Encountered by Ford Drivers

• Engine and Powertrain Codes (P-Codes): P-codes relate to the engine and powertrain. For example, P0171 indicates a lean air-fuel mixture, while P0420 relates to the efficiency of the catalytic converter.
• Chassis Codes (C-Codes): C-codes deal with the chassis, covering systems like suspension and steering. A common Ford chassis code is C1234, which refers to an issue with the wheel speed sensor.
• Body Codes (B-Codes): B-codes are linked to non-engine systems such as airbags, seat belts, and lighting. For example, B0070 points to a problem with the side airbag sensor.

Benefits of Knowing and Understanding DTCs

Knowing what your vehicle’s DTCs mean allows you to make informed decisions about repairs. Some issues are minor and can wait, while others need immediate attention.

When you address DTCs promptly, you prevent minor issues from becoming major problems.

Addressing DTCs: When to Call the Professionals

While some DTCs can be fixed by the owner, others require a professional’s expertise. If you’re unsure how to address a DTC, it’s best to visit a service center such as Five Star Ford Stone Mountain’s Service Center.

Ignoring complex issues can lead to more costly repairs later.

Before heading to a service center, note down any codes your vehicle has displayed and be ready to describe any symptoms you’ve noticed. This will help the technicians quickly diagnose and make repairs.

Visit Five Star Ford Stone Mountain

At Five Star Ford Stone Mountain, our team of experts are ready to help you with diagnostics and repairs. Our service center uses advanced tools to interpret DTCs accurately and fix any underlying issues.

Call us at (470)924-9154  or visit our crew in the city of Snellville at 3800 US-78, Snellville, GA 30039 . We can’t wait to see you!