Originally published by Vehicle Service Pros on January 6, 2026
Learn how to use the Autel Ultra S2 to diagnose these issues with bidirectional controls, scope testing and OE data.
In this new Motor Age Tech Tip, Dorman training instructor Pete Meier walks technicians through a fast, reliable way to diagnose Variable Valve Timing (VVT) issues using the Autel MaxiSYS Ultra S2.
Many drivability complaints trace back to improper valve timing, but not every vehicle offers automotive bidirectional controls, which means techs need alternative testing strategies. In this video, Meier demonstrates how the Ultra S2 serves as a full diagnostic platform, combining code scans, MOTOR TruSpeed repair information and VCMI-based engine sensor waveform analysis to validate whether a cam phaser is operating within its expected range.
Technicians will learn how to review OE and global OBDII codes, check TSBs, analyze cam and crank signals and manually command VVT actuators when necessary. Meier also shows how to compare CMP movement to CKP timing marks and how the Ultra S2’s split-screen mode simplifies monitoring data PIDs and scope patterns simultaneously.
Whether you’re diagnosing rough idle, lack of power, hesitation, or other VVT-related drivability concerns, this walkthrough provides a clear, real-world method you can use today.
