Calibrating the Direct Adaptive Steering (DAST) system on a 2017 Infiniti Q50 can be challenging. This article outlines a real-world experience and provides crucial insights into successfully completing the calibration process using a scan tool. We’ll focus on the often overlooked step that can save you hours of frustration.
Understanding the Infiniti DAST System
DAST, Infiniti’s steer-by-wire system, involves multiple components: three DAST modules (including the EPS), steering angle actuators, a steering force actuator, and a steering clutch. A malfunction in any of these can lead to DAST calibration issues. This particular case involved a vehicle where the battery and alternator were disconnected to resolve a BCM issue. While this fixed the initial problem, it resulted in a DAST system out of calibration, indicated by a significantly off-center steering wheel, limited assist, and related DTCs cascading to the ABS and ICC/ADAS systems.
Common DAST Calibration Challenges
While there’s a manual steering correction procedure and Infiniti Technical Service Bulletin (ITB18-021) addressing incomplete DAST calibration, they may not always solve complex issues. Standard DAST calibration (Mode 1) requires an alignment turntable. The system steers left and right to determine its range, decouples the clutch at the center, and allows for steering wheel centering. However, even with professional scan tools (Autel, Launch, Topdon, Snap-on, Consult-III Plus), the calibration process can fail with errors like “unable to complete” or “conditions not correct.”
The Crucial Step: Module Configuration
The key to successful DAST calibration often lies in a seemingly simple step: module configuration. The procedure involves acquiring the “Type ID” from each DAST module and the CAN gateway module (if equipped), comparing them to the FAST (service parts catalog), and then performing a configuration write. Even if the read Type IDs match the FAST IDs, performing the configuration write is essential. This was the critical oversight in the initial diagnosis.
Resolving the Calibration Issue
After realizing the missing step, a configuration write was performed on all relevant modules using Consult-III Plus. However, this initially resulted in new communication DTCs in various modules. These codes were cleared using an Autel Ultra scan tool, revealing a new “DAST calibration incomplete” DTC in DAST module 3. This confirmed that the configuration process had successfully prepared the system for calibration. Following the DTC clearing, the DAST Mode 1 calibration was initiated again using the Autel, and this time it completed without errors. Subsequent steering angle sensor position learning and a final DTC clear resolved all remaining issues.
Conclusion: The Importance of Thorough Procedures
This experience highlights the importance of meticulously following all steps outlined in the service manual and relevant TSBs when performing 2017 Infiniti Q50 DAST calibration. Even if module Type IDs match, always perform the configuration write. This seemingly minor step can be the difference between a successful calibration and hours of wasted time. While various scan tools can potentially perform the entire process, confirming compatibility with configuration writing for all involved modules is crucial. Remember, a thorough and systematic approach is essential for efficient and accurate vehicle diagnostics and repair.
