This guide explains how to activate the indirect Tire Pressure Monitoring System (TPMS) on compatible Audi vehicles using VCDS (Vag-Com Diagnostic System). This method allows you to utilize the ABS-based TPMS, eliminating the need for direct TPMS sensors. This is particularly useful for owners using winter wheel sets or seeking a solution for aging direct TPMS sensors.
Understanding Audi TPMS Systems
Audi, like Volkswagen, utilizes two primary TPMS types: direct and indirect. Direct TPMS uses sensors within each wheel to measure tire pressure and temperature, transmitting data wirelessly to the car’s computer. Indirect TPMS, relying on the ABS system, monitors wheel rotation speed. Differences in rotation speed suggest a pressure discrepancy, triggering a warning light.
While direct TPMS offers greater accuracy, indirect TPMS offers several advantages:
- No sensor replacement: Avoids the cost and hassle of replacing battery-powered direct TPMS sensors every 6-9 years.
- Simplified winter wheel swaps: Eliminates the need for a second set of sensors for winter wheels.
Activating Indirect TPMS with VCDS
This procedure focuses on activating the indirect TPMS system on Audi vehicles equipped with a compatible ABS module. Important Note: This modification might not be legal in all regions. Consult local regulations before proceeding. Furthermore, this process requires a genuine Ross-Tech VCDS cable and software.
Procedure:
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Connect and Initiate VCDS: Connect the VCDS cable to your Audi’s OBD-II port and launch the VCDS software. Ensure the cable’s green LED illuminates.
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Access ABS Controller: Select “Select,” then “ABS Controller.” The module’s part number (“VAG Number”) will be displayed. Confirm “Long Coding” is visible under “Software Coding” in green. If a number appears instead, your module may be incompatible. Click on “Coding”.
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Access Long Coding Helper: Click on “Long Coding Helper.” Crucially, record your original coding before making any changes. This allows you to revert if necessary.
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Modify Byte 16: Within the Long Coding Helper, navigate to Byte 16.
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Enable TPMS: Select the checkbox for “Bit 2 – Tire pressure monitoring (TPMS/7K6) installed.”
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Save New Coding: Exit the Long Coding Helper. The modified code will appear under “New Coding.” Click “Do it!” to save and implement the change. Exit the module.
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System Adaptation: After turning on the ignition, the TPMS light should briefly illuminate. The system requires approximately one hour of driving, including highway speeds, to adapt. TPMS readings may be unreliable during this period.
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Reset TPMS (if necessary): If a TPMS warning light persists after the adaptation period, reset the system using VCDS. Go to the ABS module’s “Basic Settings,” select “Group 042,” and click “Go!”
Conclusion
Successfully activating the indirect TPMS on your Audi using VCDS offers a convenient and cost-effective alternative to maintaining direct TPMS sensors. Remember to meticulously follow each step, document your original coding, and adhere to all local regulations concerning TPMS functionality. This modification can significantly simplify wheel maintenance and potentially reduce long-term ownership costs.
