DTCs and ADAS calibrations: What You Need to Know

ADAS calibrations aren’t optional anymore. With each make and model potentially having its own unique OEM requirements, it’s imperative for shop owners and technicians to understand when calibrations are required and which procedures to follow. 

One of the most reliable ways to identify ADAS components that are not functioning properly are Diagnostic Trouble Codes (DTCs).

Understanding how to access and interpret DTCs can make or break your calibration process. But here’s the catch: not all DTCs mean a calibration is needed, and not all required calibrations will trigger a DTC. If you don’t know how to read between the lines, you risk missed steps, customer safety issues, and liability exposure.

In this post, we’ll break down how DTCs really work, what they can and can’t tell you, and how to use them alongside OEM procedures to get ADAS repairs right every time.

What are DTCs?

Diagnostic Trouble Codes (DTCs) are signals from a vehicle’s on-board diagnostics system. When something isn’t working right, whether it’s a disconnected sensor or a misaligned camera,the ECU logs a code. A diagnostic scan tool will read those codes and can help you determine what system isn’t functioning correctly. 

 Each DTC consists of five characters:

1. First character: Indicates the system (for example, P for Powertrain, C for Chassis, B for Body, U for Network).
2. Second character: Specifies whether the code is generic (0) or manufacturer-specific (1).
3. Third character: Indicates the subsystem (for example, fuel, air metering, ignition).
4. Fourth and fifth characters: Provide a specific fault description.

A P0575 code, for example, indicates an issue with a cruise control’s input circuit. 

How DTCs work

Modern vehicles have dozens of sensors and electronic control units (ECUs), all working together in real time. When a component fails, loses communication, or operates outside of normal parameters, the system flags it. That’s when you get a DTC.

There are two main types:

• Hard codes are persistent and usually linked to active issues.
• Soft codes may appear intermittently, often due to momentary faults or loose connections.

DTCs are stored in the system’s memory and can remain even if the fault isn’t present anymore. That’s why pre- and post-scans matter: You need the full picture before and after the work.

What DTCs can and can’t tell you

Understanding the limitations of DTCs is crucial for proper ADAS service. Here's a quick breakdown:

DTCs CAN tell you:

• That a component or system has experienced a fault.
• If a sensor is completely disconnected or failing.
• If a control module is having communication issues.
• When certain components are outside their operational parameters.

DTCs CANNOT tell you:

• If a system needs calibration due to physical repositioning of another component. 
• If a sensor is slightly misaligned but still functioning.
• When OEM calibration procedures are required after repairs.
• If calibration was performed successfully. 

This is why relying solely on DTCs for ADAS repair decisions is insufficient. OEM repair procedures must be your primary guide.

The ADAS and DTC connection

ADAS systems rely on a complex network of sensors, cameras, and control modules to function properly. When these components aren't working correctly, they often—but not always—trigger DTCs.

This is where many shops make a critical mistake: assuming that no DTCs means no ADAS problems. This couldn't be further from the truth.

A camera that's misaligned by just a few degrees might still communicate with the system but provide inaccurate data. The vehicle's computer might not recognize this as a fault worth flagging with a DTC, but the consequences for the driver could be severe.

Similarly, some DTCs might not specifically mention calibration, leading techs to believe the issue can be resolved without it. This is a dangerous assumption that can lead to incomplete repairs.

Three common DTC myths debunked 

Myth #1: If there's no DTC, there's no need for calibration

This is perhaps the most dangerous misconception in ADAS repair. Many calibration requirements are triggered by physical work on the vehicle—not by system malfunctions.

For example, removing and reinstalling a bumper with radar sensors or replacing a windshield with a forward-facing camera typically requires calibration,even if no DTCs are present. The physical positioning of these components has changed, but the vehicle's computer hasn't detected an electrical fault.

Myth #2: Clearing DTCs means the system is calibrated

Clearing codes simply erases the computer's memory of a fault.It doesn't fix the underlying issue or align sensors properly. The absence of a warning light doesn't confirm proper calibration.

Only following OEM-specified calibration procedures can ensure that ADAS systems are functioning as designed. Clearing codes without proper calibration might temporarily hide an issue, but it puts your customer and your shop at serious risk.

Myth #3: Generic scan tools can identify all ADAS-related DTCs

Many shops rely on aftermarket scan tools that might not access all vehicle modules or interpret manufacturer-specific codes correctly. These tools often can't communicate with every ADAS module or may miss subtle issues that would trigger DTCs in the OEM system.

For example, a basic scan tool might not detect issues with a camera's internal calibration parameters or subtle radar misalignment. This creates a dangerous blind spot in your diagnostic process.

Vehicle-specific scan tools or comprehensive diagnostic platforms are essential for complete DTC identification. Remember that U-codes (network communication codes) are especially critical for ADAS systems, and generic scanners often miss these entirely. For this reason, it’s important to use a platform like Revv that can provide VIN-specific calibration requirements. 

When calibration is required regardless of DTCs

Many repair scenarios require ADAS calibration regardless of whether DTCs are present that indicate they’re needed. These include:

• Windshield replacement when forward-facing cameras are present. 
• Bumper repair or replacement containing radar sensors.
• Suspension work that changes vehicle ride height.
• Removal and reinstallation of any ADAS component.
• Accident repairs, even minor ones, near ADAS components.

Always check the OEM repair procedures for specific calibration requirements. Remember that these vary widely between manufacturers. What applies to a Honda may not apply to a Toyota. For this reason, automatically checking each vehicle’s OEM specifications is essential before you get started on the repair itself. 

The ideal DTC and calibration workflow

To ensure ADAS systems are properly repaired and calibrated, follow this workflow:

1. Pre-scan the vehicle to document all existing DTCs.
2. Research OEM procedures specific to the vehicle's make, model, and year with tools like Revv.
3. Determine required calibrations based on both DTCs and the physical work performed.
4. Perform all necessary repairs according to OEM specifications.
5. Conduct required calibrations using proper equipment and procedures.
6. Post-scan the vehicle to verify that all DTCs are cleared and systems are communicating properly.
7. Road test to confirm proper system operation, if applicable.
8. Document everything in detail for both the customer and your records.

This comprehensive approach ensures that no ADAS issue is overlooked, regardless of whether it triggered a DTC.

Documentation is your best protection with DTCs

Proper documentation of DTCs, calibration procedures, and verification is crucial not just for customer transparency, but for your shop's protection.

Your documentation should include:

• Pre-repair scan results showing all DTCs.
• Specific calibration procedures performed with reference to OEM requirements.
• Verification that calibrations were completed successfully.
• Post-repair scan results confirming system functionality.
• Any road testing or additional verification performed.

This documentation provides evidence that repairs were completed properly and according to manufacturer specifications. Documentation becomes all the more crucial if a vehicle is later involved in an accident.

The role of technology in DTC interpretation

DTCs provide valuable diagnostic information, but as we've seen, they're just part of the puzzle when it comes to properly calibrating ADAS systems. The real challenge lies in knowing exactly what calibrations are needed based on both the DTCs present and any repairs done on the vehicle.

This is where Revv transforms the ADAS calibration process. Our AI-powered platform helps shops navigate the complex world of ADAS calibrations with confidence by:

1. Eliminating the guesswork. Input a VIN, and Revv instantly decodes it to reveal every ADAS system on the vehicle (both equipped or optional) along with all required calibrations based on both DTCs and repair procedures.

2. Providing comprehensive documentation. Get detailed, OEM-specific calibration procedures and requirements with step-by-step instructions. This documentation is invaluable not just for technicians, but also for explaining the necessity of calibrations to customers and insurance companies.

3. Saving critical time. What typically takes 30-60 minutes of manual research is compressed into seconds. No more sifting through fragmented sources or dealing with outdated information.

4. Reducing liability exposure. With Revv, you'll have proof that you followed all OEM-required calibration procedures, protecting your shop from potential liability issues down the road.

5. Capturing additional revenue. On average, shops using Revv identify an additional $300 to $1,250 per job in billable ADAS procedures that might otherwise have been missed—procedures that are critical for vehicle safety.

Ready to see how Revv can revolutionize your approach to ADAS calibrations? Contact us today to learn more about our platform and how it can help your shop navigate the complex world of DTCs and ADAS with confidence.