What is a vehicle DTC (defect code)?
Definition of Data Trouble Codes
Les Data Trouble Codes (DTC), also called fault codes, are diagnostic codes generated automatically by the embedded electronics of a vehicle when an anomaly is detected. They are part of the vehicle's internal monitoring system and make it possible to report a malfunction as soon as a component no longer works properly or goes beyond its normal parameters.
How are fault codes generated by the vehicle?
Each modern vehicle is equipped with computers (ECUs) that continuously analyze the state of the various components: engine, battery, sensors, transmission, braking, pollution control, etc. As soon as a discrepancy is identified — for example an abnormal pressure, a faulty probe, a faulty probe, too high a temperature or an unstable battery voltage — the computer records a DTC. This code is then stored in the on-board computer and can be transmitted for analysis.
Norms and standardization (OBD-II, manufacturers)
DTCs are standardized, in particular via the standard OBD-II, which makes it possible to have a coherent reading of the faults, regardless of the manufacturer. This standardization simplifies diagnosis, facilitates the interpretation of failures and makes data usable in a multi-brand context, as is the case in car fleets.
What are DTC codes for automotive diagnostics for?
Identifying the origin of an anomaly
A DTC corresponds to a specific failure or malfunction. It allows Quickly locate the source of the problem : engine, battery, sensor, antipollution system, injection, safety, etc. Instead of repairing “blindly”, the manager or workshop has a reliable and immediate clue.
Prioritize technical interventions
Not all faults have the same criticality. DTCs help prioritize emergencies, distinguishing a minor anomaly from a defect that could result in failure or immobilization. The result: interventions are better planned, more relevant and less expensive.
Save time on workshop diagnostics
Thanks to fault codes, workshops and technical teams save precious time. The DTC gives a clear direction to diagnosis, reduces fault-finding costs, and accelerates the return of vehicles to service.
DTC feedback via embedded telematics
CAN boxes and native manufacturer boxes
In an environment of car fleet management, the DTCs are retrieved via the embedded telematics. This connection is made using telematics boxes CAN (installed afterwards) or via native telematics boxes already pre-installed by some manufacturers. Note that OPTIMUM benefits from official approvals from car manufacturers RENAULT and STELLANTIS, allowing it to exploit data from native devices.
Automatic transmission of alerts in real time
Once the vehicle is connected, DTCs are transmitted automatically to the fleet management platform. Defects are reported in real time, without driver intervention, which allows you to be alerted immediately in the event of a problem.
Reliability of data from the on-board computer
The information comes directly from the vehicle's on-board computer. So they are factual, reliable and continuously updated. This level of precision is essential to manage a fleet rigorously and to anticipate technical risks.
What types of DTC data can we track in a fleet?
Engine, emissions and pollution control system
DTCs cover a wide mechanical and electronic perimeter. In particular, they make it possible to monitor faults related to motor, the injection system, the particulate filter, the EGR valve or any element associated with polluting emissions.
Battery, power and electrical components
On electric and hybrid vehicles, DTCs are particularly useful for monitoring traction battery, high-voltage systems, the charger, or even the energy management units.
Maintenance levels, sensors and indicators
Telematics also makes it possible to report additional data related to the overall proper functioning of the vehicle: oil levels, fuel level, engine temperature, Mileage counter, sensor alerts, or maintenance deadlines.
DTC and preventive maintenance: anticipate breakdowns
Detecting a problem prior to immobilization
One of the great benefits of DTCs is the ability to anticipate breakdowns. An anomaly detected early can be treated before it leads to breakage, prolonged immobilization or an incident on the road.
Schedule maintenance at the right time
The DTC lifts allow you to schedule maintenance at the best time, based on the actual condition of the vehicle. Operations that are too early (unnecessary cost) or too late (risk of failure) are thus avoided.
Extend the life of vehicles
By intervening at the right time, vehicles are better maintained, which contributes to extend their lifespan and to limit the premature wear of components.
Reducing costs and fixed assets with DTCs
Decrease heavy repairs
A failure that is detected late is often much more expensive. DTCs help avoid heavy repairs by treating anomalies as soon as they appear.
Improving the availability of the park
Fewer unexpected breakdowns mean fewer immobilized vehicles. DTCs participate directly in improve fleet availability, and therefore business continuity.
Optimize TCO (total cost of ownership)
By reducing fixed assets, emergency interventions, and major repairs, DTCs contribute to lowering the TCO (Total Cost of Ownership) and to better control fleet budgets.
Exploiting DTCs in OPTIMUM Automotive
Centralized alerts in the vehicle sheet
At OPTIMUM Automotive, DTCs are integrated directly into the Vehicle sheet. Managers have a single point of access to visualize technical status, current alerts, and key indicators.
History and follow-up of anomalies
The platform maintains a full history anomalies detected. This monitoring makes it possible to identify recurrent faults, to assess the evolution of a vehicle and to better manage maintenance over time.
Decision support for maintenance and renewal
By combining DTCs with usage data (mileage, consumption, driving behavior), OPTIMUM helps companies to make better decisions : prioritization of interventions, renewal planning, and choice of the most suitable engines.
