Understanding your car’s performance, especially if it’s tuned, requires logging critical data. This guide explains how to use Ross-Tech VCDS (VAGCOM) software and cable for basic performance logging. We’ll walk you through the setup and logging process, using VCDS to gain valuable insights into your vehicle’s operation.
Preparing for VCDS Logging
Before diving into logging, ensure your setup is correct and your car is free of faults.
Equipment and Software
- Ross-Tech VCDS Cable: Connect this to your car’s OBDII port.
- VCDS Software: Install the latest version on a Windows-based computer.
- Vehicle: Your car should be operational and ready for testing.
Initial Checks
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Connect and Launch: Plug the VCDS cable into the OBDII port under the driver’s side dash. With the car in the ‘ON’ position, launch the VCDS software.
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Fault Code Scan: In VCDS, click ‘Auto-Scan’ and then ‘Start’ to check for fault codes. Address any existing faults before proceeding with logging. Clear codes using the ‘Clear all DTC’s’ button if necessary.
Setting Up VCDS for Logging
Once your car is ready, you can configure VCDS to record the desired data.
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Select Engine Module: Click ‘Select’ under ‘Select Control Module’, then choose ’01-Engine’ under the ‘Common’ tab.
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Access Advanced Measuring Values: In the Engine Controller module, click ‘Adv. Meas. Values’ to open the logging section.
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Record Ambient Air Pressure: Select and record the ‘Ambient Air Pressure’ value for later boost calculations. Uncheck the box after recording.
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Choose Logging Parameters: Select the specific parameters you want to log (up to 10 with grouping). Essential parameters often include:
- Accelerator Position
- Charge Air Pressure (Specified and Actual)
- Engine Speed (RPM)
- Air Mass
- Ignition Angle (Actual)
- Intake Air Temperature
- Knock Detection
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Save Parameter List: Click the VCDS icon, save the selected parameters as a list (e.g., “Performance”), for easy access in future sessions.
Initiating and Capturing the Log
With the setup complete, you can start logging real-time data.
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Enable Turbo Mode and Grouping: Crucially, press the ‘Turbo’ button and check ‘Group UDS requests’. This ensures faster logging and aligns all parameters to the same timestamp.
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Start Logging: Press ‘Log’, then ‘Start’ to begin recording data. Ensure your car is running.
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Perform Logging Run: Conduct your logging run in a safe, controlled environment. A full 3rd or 4th gear pull from around 3000 RPM to 7000 RPM is recommended. Turn OFF A/C, radio; windows UP; dynamic mode ON (if available); traction/ASR OFF.
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Stop Logging: Once finished, press ‘Stop’ and then ‘Done, close’. Log files are saved as .CSV files in the Ross-Tech/VCDS/Logs folder, viewable in Excel.
This guide provides a foundational understanding of how to see real-time VCDS data. Further analysis of the logged data will allow you to interpret your car’s performance and diagnose potential issues. Remember to consult Ross-Tech’s documentation for specific parameter details and troubleshooting. Additionally, researching online forums can provide valuable insights from experienced VCDS users.
