Mastering Diagnostics #21: Leveraging scan tool functions to build a VVT diagnostic game plan

Feb. 18, 2025

In this episode of Mastering Diagnostics, Motor Age Technical Editor Brandon Steckler outlines how a preliminary plan and robust service information system keep you from wasting time.

Brandon Steckler

Where great driveability diagnosticians shine above the rest is not so much what they know about the vehicles they are addressing. It’s how they learn to leverage the tools they have to build a diagnostic game plan. This holds true with all systems but especially with the widely implemented variable valve timing (VVT) system. With factors such as hydraulics, induction, duty cycle, and what every other circuit on the vehicle faces, determining what not to test is a valuable discovery.

The tools that take these techs to the next level are multi-faceted. Through the power of a robust service information system and a capable scan tool, so much can be derived right from the driver’s seat. What’s the point? Not to waste time testing unnecessarily.

To eliminate items off a list of potential faults is crucial for accurate and efficient diagnostics. To first visit service information allows a technician to understand a system’s configuration. This is always a necessary first step. But where the true leverage comes is in the power of diagnostic tooling like that of the Bosch ADS 625X.

Beginning first with basic graphed scan data, a technician can ascertain if what should be occurring is being carried out correctly. Think of this like a “go/no-go” type test. If a system isn’t functioning correctly, locating the faulted area is the next logical step.

With a capable scan tool exhibiting strong enhanced data availability, a technician can force system functionality through a bi-directional system test. Requesting control of the system forces the components to work as a system and under the direction of the ECU’s software. This flushes a suspect area into the crosshairs, so to speak.

Once a suspect area of the system is narrowed down, bi-directional control of individual components can be manipulated, allowing circuit testing to be carried out without having to drive the vehicle under normal road test conditions. All the dynamic testing can be carried out in the work bay, where the tools are. This, in combination with circuit testing tools, allows a technician to locate the root cause of the fault accurately and efficiently. Tools like the Bosch ADS 625X allow this to happen seamlessly making driveability challenges a pleasure to address. Click here to learn more about the Bosch ADS 625X diagnostic scan tool.

About the Author

Brandon Steckler | Technical Editor | Motor Age

Brandon began his career in Northampton County Community College in Bethlehem, Pennsylvania, where he was a student of GM’s Automotive Service Educational program. In 2001, he graduated top of his class and earned the GM Leadership award for his efforts. He later began working as a technician at a Saturn dealership in Reading, Pennsylvania, where he quickly attained Master Technician status. He later transitioned to working with Hondas, where he aggressively worked to attain another Master Technician status.

Always having a passion for a full understanding of system/component functionality, he rapidly earned a reputation for deciphering strange failures at an efficient pace and became known as an information specialist among the staff and peers at the dealership. In search of new challenges, he transitioned away from the dealership and to the independent world, where he specialized in diagnostics and driveability.

Today, he is an instructor with both Carquest Technical Institute and Worldpac Training Institute. Along with beta testing for Automotive Test Solutions, he develops curriculum/submits case studies for educational purposes. Through Steckler Automotive Technical Services, LLC., Brandon also provides telephone and live technical support, as well as private training, for technicians all across the world.

Brandon holds ASE certifications A1-A9 as well as C1 (Service Consultant). He is certified as an Advanced Level Specialist in L1 (Advanced Engine Performance), L2 (Advanced Diesel Engine Performance), L3 (Hybrid/EV Specialist), L4 (ADAS) and xEV-Level 2 (Technician electrical safety).

He contributes weekly to Facebook automotive chat groups, has authored several books and classes, and truly enjoys traveling across the globe to help other technicians attain a level of understanding that will serve them well throughout their careers.