2025-2026 Audi Driver Assist System Warning TSB 2081073/1

Introduction

Audi has issued Technical Service Bulletin (TSB) 2081073/1 to address a specific concern affecting certain 2025 and 2026 Audi models. This bulletin provides comprehensive information for diagnosing and resolving unexpected warning messages related to the vehicle's driver assist systems. Owners of models such as the Audi A5, A6, Q5, S5, and SQ5 may experience a prominent "take over steering prompt" along with other driver assist system fault messages, often accompanied by the diagnostic trouble code (DTC) U171200. This TSB supersedes the previous bulletin PSS 2079757, titled "90 PSS PPE/PPC: warning messages about assist systems – U171200," and offers an updated solution for the Audi A6 driver assist system warning and related issues.

Important Diagnostic Notes

Audi has provided specific conditions under which this Technical Service Bulletin (TSB) 2081073/1 applies. It is crucial for both owners and technicians to understand these limitations to ensure proper diagnosis and avoid unnecessary repairs:

• TSB Applicability for "Take Over Steering Prompt": This TSB does NOT apply if the red warning lamp for the "take over steering prompt" is not active. The presence of this specific warning light (depicted as a steering wheel with hands and an exclamation mark) is a key indicator for this particular issue.
• Multiple Fault Messages Required: This TSB does NOT apply if only some of the fault messages listed below have occurred or are currently active. The issue described by this bulletin is characterized by a broader system malfunction, typically involving multiple driver assist system warnings.
• Exclusion for Restricted Visibility: The TSB is also NOT applicable if notifications are displayed stating various driver assist systems are not available due to restricted visibility. Warnings caused by environmental factors (e.g., snow, heavy rain, fog blocking sensors) are not addressed by this software update.

Symptoms and Warning Messages

Owners of affected Audi vehicles, including the 2025-2026 Audi A5, A6, Q5, S5, and SQ5, may observe various fault messages appearing on their instrument cluster shortly after starting the vehicle. These warnings are typically displayed in conjunction with a distinct visual cue: a red warning lamp for the "take over steering prompt." This visual alert, shown as a steering wheel icon, signals an immediate concern with the steering or driver assistance systems.

The specific driver assist system warnings that may appear include, but are not limited to, the following verbatim messages:

• "Adaptive cruise assist: fault. You can continue driving"
• "Lane departure warning: fault. You can continue driving"
• "Active front assist / distance warning: fault. You can continue driving"
• "Traffic sign recognition: fault. You can continue driving"
• "Adaptive light: fault"
• "Main beam assist: fault"
• "Lane change assist: currently unavailable"
• "Proactive occupant protection: currently unavailable"
• "Driver assist systems currently restricted"
• "Emergency Assist: fault. You can continue driving" (in combination with the red "take over steering prompt")

These messages collectively indicate a potential malfunction within the vehicle's advanced driver assistance systems (ADAS), impacting their intended functionality. While some messages suggest that driving can continue, the presence of multiple warnings and the "take over steering prompt" indicates a significant system anomaly, often pointing to the underlying Audi A6 driver assist system warning issue.

Diagnostic Trouble Codes (DTCs) and Fault Conditions

When the symptoms described above are present, technicians will typically find a specific diagnostic trouble code (DTC) logged in the vehicle's systems. The primary fault code associated with this issue is U171200, which is described as "Driver assistance main control module, no communication, active/static with symptom 4540." This code is logged in the Data Bus On Board Diagnostic Interface, specifically the J1273 control unit, which corresponds to diagnostic address 0019.

Further complicating diagnosis, technicians may find it impossible to read out the diagnostic addresses 00A5 and 8103 using the ODIS diagnostic system. These addresses are typically associated with critical control modules within the driver assistance network. The inability to access them, combined with the U171200 DTC, strongly points to a communication breakdown within the system, preventing proper operation of the driver assistance features.

For this TSB to apply, the complaint must involve the following issues occurring simultaneously:

• Active warnings are present in the instrument cluster.
• Diagnostic addresses 00A5 and 8103 cannot be accessed via ODIS.
• The specified event memory entry (DTC U171200) is logged in the J1273 control unit.

Technical Background

The root cause of this issue is identified as a software problem within the Data Bus Diagnostic Interface Control Unit, designated as J1273 (diagnostic address 0019). This control unit acts as a central gateway, facilitating communication between various driver assistance modules and the rest of the vehicle's electrical system. The software anomaly leads to intermittent communication failures, particularly shortly after the ignition is switched on.

This communication disruption results in the Audi A6 driver assist system warning messages and the U171200 DTC. The fault typically affects the vehicle for one complete driving cycle. Interestingly, the system can temporarily self-correct after a bus sleep cycle. A bus sleep cycle is achieved by switching off the ignition, locking the vehicle, and then waiting for approximately 3 minutes. This temporary remedy highlights the intermittent nature of the software glitch.

Diagnosis in the Workshop

Audi outlines specific procedures for technicians to confirm the customer's complaint and determine if TSB 2081073/1 is applicable.

Reproducing the Customer Concern

If the customer's concern can be reproduced in the workshop, it means the active messages are present in the instrument cluster. For the complaint to align with this TSB, the following conditions must be met during diagnosis via ODIS:

• Warning messages must be active.
• Diagnosis for diagnostic addresses 00A5 and 8103 must not be possible (these addresses cannot be read out).
• DTC U171200 "Driver assistance main control module, no communication, active/static with symptom 4540" must be logged in the Data Bus On Board Diagnostic Interface, J1273 (diagnostic address 0019).

This specific combination of active warnings, inaccessible diagnostic addresses, and the U171200 DTC confirms the software issue described in the TSB. The complaint can be temporarily remedied by a terminal 30 reset of the "Diagnostic interface or data bus J1273" or by a bus sleep cycle, which starts approximately 3 minutes after switching off the ignition and locking the vehicle.

When the Complaint Cannot Be Reproduced

If the customer complaint cannot be reproduced in the workshop (i.e., the warnings are not active at the time of diagnosis), the only indication that this TSB applies is the presence of DTC U171200 as "Driver assistance main control module, no communication, passive/intermittent with symptom 4540" in diagnostic address 0019. In such cases, corresponding documentation (e.g., photos or videos) provided by the customer is essential. Technicians should verify that the event memory's ambient conditions, date, time, and frequency counter match the customer's reported complaint to confirm the functional impairment.

Repair Procedure: Software Update

The resolution for the Audi A6 driver assist system warning involves a software update to the Data Bus Diagnostic Interface Control Unit, J1273. This procedure utilizes Audi's Software Version Management (SVM) system and a specific SVM code.

General Instructions and Prerequisites for Flashing

Technicians must follow all instructions outlined in TSB 2011732: "00 Software Version Management (SVM), operating instructions." Key prerequisites and steps include:

• The driver door must remain open for the entire duration of the flashing procedure.
• Before entering the SVM code, verify that the current date and time are correctly displayed in the vehicle. If not, move the vehicle to a location with GPS reception or manually set the date and time. Incorrect date/time will prevent or abort the update.
• No additional work or operations may be performed on the vehicle while the update is in progress.
• Connect a battery charger unit according to workshop specifications to maintain stable voltage.
• Switch off all non-essential electrical equipment, such as the blower, seat heaters, and lights.
• Move the selector lever to position P.
• Connect the diagnostic tester to the vehicle using a USB cable. Audi strongly recommends using a USB cable for flashing to ensure reliable data transmission.

SVM Test Plan Execution

To perform the software update, technicians will follow these steps within the ODIS diagnostic system, referencing the "ODIS SVM Test Plan" (Figure 2 in the original document):

1. Run the test program "SVM – Check vehicle configuration" in ODIS. This step is necessary before using the SVM code.
2. Select the "Flash" function, then choose "SVM code input." Enter the specific SVM code: EGDHCP5DA0019.
3. The flashing procedure will commence. Due to a system restriction, the process will conclude with error 8113. This error should be ignored. If any other error code appears, technicians must proceed as specified in that error message.
4. After the flashing, run the "SVM – Check vehicle configuration" test program in ODIS again.
5. Perform a bus sleep cycle, end the diagnostic session, and send the diagnostic log online.

It is important to note that the SVM code is specifically used for diagnostic address 0019 and does not result in any changes to the vehicle's identification data, such as part numbers or software versions.

Warranty Information

For vehicles experiencing the Audi A6 driver assist system warning and related issues, Audi provides specific guidelines for warranty claims:

• Claim Type: If the vehicle is outside of its warranty period, this Technical Service Bulletin is for informational purposes only, and the repair may not be covered.
• Service Number: 9035
• Damage Code: 0039
• Labor Operations:
  • 0151 0010: Software update (Refer to the Service Repair Time (SRT) document for associated operations).
  • 0151 0060: Software update (Time stated on the diagnostic protocol).
• Claim Comment: As per TSB 2081073/1.

All warranty claims submitted for payment must adhere to the Audi Warranty Policies and Procedures Manual. Claims are subject to review or audit by Audi Warranty.

NHTSA ID: 11029436