DTC Codes: The Key to Reducing Downtime on Company Vehicles
Every day one of your drivers continues to use a vehicle with illuminating DTC codes, it puts your business at risk.
That could come in the form of spending more money on costly repairs that leaves a vehicle out of service, treading the fine line on compliance, and even leaving your employees stranded in a broken-down vehicle.
At Vestige, we recognize the significance of staying informed about vehicle health. Our comprehensive guide will walk you through the basics of DTC codes, how to interpret them, and the steps you can take to keep your vehicles running smoothly.
Whether you’re a fleet manager or a transportation director or a mechanic in need of a brush up, this guide will provide you with the knowledge you need to make informed decisions about your vehicle’s maintenance and repair needs.
Vestige has invested in a new DTC module in our software that makes it simple to see which vehicle is operating out of specifications and where you need to take action to prevent potential larger challenges.
Learn about Vestige’s role in fleet safety.
Vestige is a national leader in fleet and people safety with a full integrated solution that includes AI-powered 360 degree vehicle cameras, body cameras and well as personal safety devices known also known as panic buttons.
See how SalSon Logistics turned a $9 million insurance problem into a strategic advantage
Accident payouts dropped from six‑figure annual totals to under $200,000 by 2024.
Better yet, drivers are protected, insurers are competing for their business, and a stronger safety culture now fuels their profitability.
But First, What is a DTC Code?
Most of us are all too familiar with the dreaded Check Engine Light. This bright orange logo pops up when your vehicle receives a specific DTC code.
“DTC” is an acronym for Diagnostic Trouble Codes. These are alphanumeric codes generated by a vehicle’s on board diagnostics system when it detects something is wrong.
These codes serve as a crucial tool for identifying and diagnosing problems. That’s why when you take your vehicle to a car shop, one of the first things they do is “run diagnostics”.
By promptly addressing issues indicated by these codes, you can prevent minor problems from escalating into major repairs, saving your business time and money in the long run.
If you run a business where your employees need to utilize a company vehicle, you must adhere to federal emissions regulations in order to avoid potential legal issues.
A smart place to start would be to understand the basics of a vehicle’s diagnostic codes, and what causes them.
By monitoring driving behavior with Vestige, fleet managers can then hold their drivers more accountable for unsatisfactory driving behavior that often leads to costly maintenance that could’ve been prevented.
Vestige’s Industry-leading vehicle monitoring solutions include dash cams and a suite of 360 vehicle cameras that provides complete vehicle protection, alongside GPS tracking and real-time alerts that play a vital role in capturing critical driving data that can help you manage DTC code reports.
Vestige is trusted by more than 2,000 customers operating across nearly every commercial vehicle industry. From long haul trucking and complex logistics to community HVAC providers and regional tow and recovery vehicles, Vestige is trusted as the essential fleet and safety platform.
TRUSTED BY INDUSTRY LEADERS
Why DTC Codes Matter
If you have a vehicle that was manufactured in 1996 or later, it has a standardized system implemented called the OBD-II, short for
On-Board Diagnostics II.
This system monitors and reports the health and performance of a vehicle’s engine and other essential components.
One of the most critical aspects of this system is its ability to generate your DTC Codes, and therefore help mechanics and vehicle owners identify and address problems. And when it’s built into a fleet safety software like Vestige, the instant DTC codes can serve as powerful tools to drive improved vehicle performance and stave off issues before they become more serious.
Predictive Maintenance
Reading and analyzing these codes early helps prevent breakdowns and extend the life of fleet vehicles.
For example, a P0171 code is set by your vehicle’s powertrain control module (PCM) when it detects that the air-to-fuel ratio of your vehicle is too lean. This means that the PCM is relaying that the engine is receiving too much air into the combustion chamber and not enough fuel.
Reduced Downtime
The sooner the vehicle gets back in working condition, the better. Technicians use DTC codes to quickly pinpoint problems and reduce the time it takes to address the issue and get your truck back on the road as soon as possible.
Vestige collaborates with partner companies FASTER to support advanced fleet maintenance operations to drive better vehicle maintenance and management.
Cost Control
This goes hand-in-hand with preventive maintenance. Accurate diagnostics mean fewer unnecessary part replacements and faster repairs.
Using OBD-II data eliminates guesswork, saving on labor and parts.
Emissions & Compliance
Fleet vehicles must often comply with state or federal EPA Emissions Regulations, and unresolved trouble codes can prevent a vehicle from passing inspections.
To maintain compliance requirements and protect the reputation of your company, it’s crucial that you understand the importance of DTC codes and address them right away.
Having the codes fed directly and immediately into your GPS fleet tracking and safety camera solution is a powerful shortcut to ensure you have the DTC codes you need to remain proactive.
Data-Driven Decisions
Incorporating OBD-II data into your fleet management software or telematics platform allows for better tracking of vehicle health, driver behavior, and maintenance planning.
Vestige Fleet Multi-Cameras & GPS Tracking Features
Vestige Fleet Multi-Cameras & GPS Tracking Features
With Vestige, you can install up to eight HD dash cams on each vehicle. The cameras will be placed all around the vehicle, including one monitoring the driver’s actions, giving you a full view of everything that is happening.
Live Video Streaming
With our 4G LTE remote connection, you can access live high-quality video footage of everything the cameras capture. This integrated video solution lets you track performances easily and check for any unsafe driving behaviors that need improvement.
Cloud-based Video Portal
All video recordings will be retrievable from the cloud for 90 days. You have easy access to video clips for a post-incident analysis, making performance tracking more streamlined. You can also access additional video evidence for an accident in the portal, allowing you to protect your business from liability claims with video proof.
Automatic Video Uploads and Alerts
Vestige allows you to create notifications for vehicle accidents and other harsh driving events. You can get alerts within minutes of an unsafe event. The event video file will be uploaded to the cloud right away, allowing you to watch it anytime you want with on-demand video retrieval.
Using an OBD-II Scanner to Read DTC Codes
When the check engine light comes on, the first step to resolving it is to run a diagnostics scan for DTC codes, using an OBD-II (On-Board Diagnostics II) scanner.
This handheld device, also seen under the name OBD2 scanner, plugs into your vehicle’s diagnostic port and retrieves the triggered DTC codes from your vehicle’s on board diagnostics system.
Once you’ve obtained the DTC codes, the next step is to interpret them accurately. These codes follow a general format with a letter prefix, followed by four digits.
The letter prefix indicates the category of the code, while the digits provide specific information about the issue.
P0420 is a common code that relates to the catalytic converter’s efficiency. To better understand how we get to this conclusion, we need to understand each part of the code.
With the Vestige software, vehicle owners are able to capture and interpret the codes from the convenience of their work computer or mobile digital device, meaning vehicle problems can be caught early and managed before a vehicle becomes inoperative.
Vestige features unlimited seats for each user, meaning your team can ensure everyone has the access required to maintain vigilance about vehicle conditions.
How to Read DTC Codes
Every DTC code has a standardized format. This structure g
ives technicians or systems a clear diagnostic trail.
For a better understanding, we will identify each character of a code here and provide a concrete example with the code P0420.
The First Character is Always a Letter
There are four Letter categories.
In the case for P0420, “P” indicates an issue with the Powertrain. (We’ll get to the other codes in a moment.)
The Second Character is Either 0 or 1
If the second character in your DTC code is 0, this indicates an issue that can occur in any vehicle.
If it’s a 1, that means it’s specific to your make or model. The same code can have different meanings depending on the manufacturer. This is why it’s important to first know your vehicle’s make and model before looking up codes.
In the case of DTC P0420, this code can happen to pretty much any vehicle.
The Third Character Can Range From 1 through 8
- 1 means you have a problem with your fuel or air metering system
- 2 signals a problem with the fuel or air metering injection system
- 3 is the ignition system
- 4, which is where P0420 falls, indicates an emissions system issue
- 5 has to do with the vehicle speed controls or idle control
- 6 points to the computer output circuit
- Numbers 7 and 8 indicate it’s something related to your transmission
The Last Two Numbers Will Provide Your Exact Code
This number ranges from 0 to 99. In the case for P0420, the number 20 means you have a Catalyst efficiency below threshold.
Know When and Why DTC Codes Happen
By combining these alert features with a foundational knowledge of DTC codes, fleet managers can quickly identify and address issues, minimizing downtime, ensuring optimal vehicle performance, and saving money on avoidable repairs.
Vestige offers tiered alerts for various unsafe driving behaviors, helping maintain driver safety standards by notifying when behaviors like harsh braking, rapid acceleration, or fatigue occur.
The real-time AI-powered alerts for distracted driving and device use can help transform the way a fleet responds to dangerous driving habits. Both the driver and a manager can be alerted in real time, ensuring there’s no excuse for repeated bad behavior behind the wheel.
Extended List of DTC Codes and What They Mean
By understanding the triggered DTC codes, fleet managers can make informed decisions about vehicle maintenance and repairs, ultimately extending the life of their vehicles.
DTC codes are divided into four letter categories, each focusing on a specific area of the vehicle:
P-Codes
P-Codes are your Powertrain Codes, which involve engine, transmission, and associated systems. Here are a few P-Codes that you might see when you run diagnostics.
- P0171: System too lean (Bank 1) – Meaning the combustion chamber is receiving too much air and you aren’t getting enough fuel into your engine.
- P0300: Cylinder Misfire Detected – Points to issues with fuel delivery or the ignition with random or multiple cylinders. Codes between P0301 and P0306 indicate which of your 6 cylinders (or however many you have) are experiencing a misfire.
- P0420: Catalyst System Efficiency Below Threshold (Bank 1) – Often a failing catalytic converter or oxygen sensor.
Don’t see yours listed here? Click here for a more extensive list of possible P-Codes
B-Codes
These are your Body Codes, which cover issues with the body control modules, such as power locks, windows, and airbag systems.
Click here for a full list of B-Codes
C-codes
These codes refer to Chassis systems, such as the brakes, suspension, and steering.
Click here to view the complete list of C-Codes
U-codes
An U-code indicates an issue with the Network, which indicates a problem within the vehicle’s communication networks.
View a more in-depth list of U-Codes
While some codes may indicate minor issues that can be addressed during routine maintenance, others may require immediate attention to prevent further damage or safety concerns.
With Vestige View’s advanced camera features, including multi-angle coverage and event-based recording, you can receive valuable insights into driving incidents that can be used in tandem with DTC codes to reduce overall maintenance costs.
Integrating Tech Into Your Fleet Management Strategy
You can reduce downtime, control costs, and keep vehicles on the road longer by simply investing in overlooked tools, such as an OBD-II scanner. The smarter option is to not wait until the vehicle is in the shop and to have a fully integrated software solution like Vestige that delivers DTC codes as they appear in your vehicle, regardless of its location.
When integrated properly into your fleet management strategy, this data can support in-vehicle technology that offers real-time insights and long-term benefits that go far beyond simple code reading.
Assign Each Vehicle Its Own Tech
You could stock each vehicle with an OBD-II scanner to help your team diagnose codes on-the-go or you can invest in a more system that delivers 360 degree vehicle camera footage, and also includes a fully integrated body camera solution and personal safety device, known as PERSA at Vestige.
Schedule Maintenance
Base routine maintenance on actual vehicle conditions. Don’t wait until you hit a certain amount of miles on the odometer. Every vehicle is different and is subject to varying road and maintenance conditions. Drivers and fleet managers need to stay connected so the DTC codes don’t become your last line of defense.
Educate Your Employees
Train your drivers and in-house techs on how to recognize common codes, so they can respond sooner and more appropriately.
This can be as simple as sharing this document or creating your own version so drivers can be aware of a code that is commonplace and may not require immediate treatment, and one that is more serious and demands immediate maintenance.
Log and Track Reported DTC Codes
This can help you catch recurring issues and identify systemic problems or driver-related wear patterns that can be resolved with retraining. .
Fleet vehicles and their ongoing maintenance are normally one of the largest expenses for a public or private fleet and there’s a wealth of knowledge online about how to best manage maintenance before, during and after DTC code responses.
Vestige Can Help Keep Your Vehicles Running Smooth
Between fleet managers and their staff, being familiar with these codes and their meanings gives your organization an advantage in keeping vehicles in strong condition.
At Vestige, we’re committed to providing cutting-edge solutions for vehicle diagnostics and monitoring your fleet to further extend the life of your vehicles and hold teams accountable for behaviors that may trigger DTC codes.
Our products and services, including advanced AI-powered 360-degree vehicle camera systems and real-time safety alerts, can help you drive a culture of safety and accountability across your team.
By partnering with us, you can benefit from lower insurance premiums, improved safety, and increased overall efficiency.
Don’t wait until a problem can no longer be ignored. Take action today to keep your vehicle on the road and in top shape.
Together, we can ensure that your vehicles remain safe, reliable, and compliant with all necessary regulations.
