2021-2023 Audi Q7, A6, A7, Q8 EPC Light with DTC B10581B

Audi has issued Technical Service Bulletin (TSB) 2070211/1 to address a specific condition affecting various 2021-2023 Audi models, including the Q7, A6, A7, and Q8. Owners may notice an EPC warning and a fuel system warning displayed in their instrument cluster. This issue is often associated with a diagnostic trouble code (DTC) B10581B, indicating a problem with the fuel level sensor.

This TSB, titled "20 EPC Light on: Fuel level sender DTC entry B10581B Resistance too high," provides a software-based solution to correct the underlying cause. The Audi EPC light B10581B condition is not due to a faulty hardware component but rather an over-sensitive diagnostic system.

Symptoms

Owners of affected Audi vehicles may experience two primary warning messages appearing in their instrument cluster. These include an EPC warning light, which typically indicates an issue with the engine's electronic power control system, and a fuel system warning. Both warnings signal a potential problem that requires attention. If you encounter an Audi EPC light B10581B, it's important to have your vehicle diagnosed.

Fault Codes / DTCs

When diagnosing this condition, technicians will typically find a specific diagnostic trouble code stored in the vehicle's Comfort System Central Control Module, identified as J393 (address word 0046). The relevant DTC is:

This B10581B Fuel level sensor 2 Resistance too high code, despite its description, points to a diagnostic sensitivity issue rather than a direct sensor failure.

Technical Background

The root cause of the Audi EPC light B10581B and associated fuel system warning is identified as overly sensitive On-Board Diagnostics (OBD). The vehicle's diagnostic system, specifically within the J393 Comfort System Central Control Module, is too quick to register a resistance value from the fuel level sensor 2 as being too high. This sensitivity triggers the warnings and stores the DTC B10581B, even when there is no actual defect with the fuel level sensor itself.

Repair Procedure Summary

The resolution for this condition involves a software update to the Comfort System Central Control Module (J393). This update recalibrates the diagnostic thresholds, preventing the system from misinterpreting normal fuel level sensor readings as faults. The repair process, as outlined in TSB 2070211/1, requires technicians to:

1. Refer to and follow all instructions detailed in TSB 2011732, which covers general Software Version Management (SVM) operating procedures. This ensures the update is performed correctly and safely.
2. Update the J393 module (address 0046) using the appropriate SVM action code. The SVM code input for this update is 46A033. The TSB provides a detailed table listing specific old and new software part numbers and versions for various models and model years. For instance, an A6/A7 MY19 might update from old software part number 4K8909501D to new software part number 4K8909501D with a new software version 0037, while a Q7 MY22 might update from 4M0909501AA to 4M0909501AA with new software version 0089. These updates ensure the J393 module operates with the corrected diagnostic logic, resolving the Audi EPC light B10581B issue.

Warranty Information

Audi provides specific warranty coverage for this software update. For vehicles still under the new vehicle limited warranty, the repair is covered up to 48 months or 50,000 miles, whichever comes first, under Claim Type 110. Certified Pre-Owned (CPO) vehicles may also be covered under Claim Type G10, though owners should verify their specific coverage. The service number for this repair is 2015, with a damage code of 0040. The labor operation for the software update, including checking for DTCs, is 0151 0000, with a maximum time allowance of 50 time units (TU). Diagnostic time is categorized as GFF with no allowance.

Important Warnings

Owners should be aware that if their vehicle falls outside of the specified warranty periods (48 months/50,000 miles or CPO coverage), this Technical Service Bulletin is for informational purposes only. In such cases, the cost of the software update may not be covered by Audi warranty. All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual and are subject to review or audit by Audi Warranty.

NHTSA ID: 10236576