2025 Audi A5/Q5/S5 Drive System Fault DTC P071100

Owners of certain 2025 Audi A5, Q5, and S5 models may observe a "drive system fault in instrument cluster" message or a warning lamp illuminating in the dash panel. This condition is addressed by Audi Technical Service Bulletin (TSB) 2079998/1, which outlines a software optimization to resolve the underlying issue. This TSB specifically targets vehicles that may log certain diagnostic trouble codes (DTCs) related to the gearbox and transmission fluid temperature, even if there isn't a direct customer complaint beyond the warning light. The recommended repair for the 2025 Audi A5 drive system fault is a software update to the gearbox electronics control unit.

Symptoms

The primary symptom owners might notice is the "drive system fault warning lamp lights up in the dash panel insert." In some cases, there might not be an immediate, noticeable driving issue, but the warning light indicates a fault has been detected by the vehicle's systems. It's also possible for the event memory entry to be present in the gearbox electronics control unit J217 without a direct customer complaint, indicating a latent issue.

Fault Codes / DTCs

Technicians may find the following diagnostic trouble codes (DTCs) logged in the gearbox electronics control unit (diagnostic address 0002). These codes can be static or intermittent:

Code	Description	Symptom ID
P071100	"Transmission Fluid Temperature Sensor "A" Circuit Range/Performance"	20756
P270800	"Solenoid Valve 6 is sticking on"	20859

Diagnosis / Trigger Conditions

Diagnosis typically involves checking the event memory of the gearbox electronics control unit J217. The presence of DTC P071100 or P270800, especially in conjunction with the "drive system fault in instrument cluster" warning, indicates that the vehicle is affected by this TSB. These event memory entries can be static or intermittent. The underlying cause is identified as optimized software that requires an update.

Repair Procedure Summary

The repair for the 2025 Audi A5 drive system fault involves performing a software update to the gearbox electronics control unit. This update is designed to optimize the existing software. The procedure requires connecting a battery charger to the vehicle during the update process to ensure stable voltage. Technicians will perform a fixed-rate software update, which includes all necessary preliminary and follow-up work, such as bus sleep cycle management, calibration drives, and restarting the software update if flashing is interrupted.

This Technical Service Bulletin 2079998/1 supersedes the previous TSB 2078847, providing the most current solution for this specific drive system fault. The service number for this operation is 3730, with a damage code of KD02. Labor operations include 0151 0010 for software update with battery charger connection, and 0151 0040 for a fixed-rate software update, which accounts for 130 time units (TU).

Important Warnings for Owners

Owners should be aware of critical information regarding software updates, especially if their vehicle's engine control unit has been modified through chip tuning. Audi advises customers to inform their service center if the engine control unit has been altered. Updating the engine control unit software will render any chip tuning ineffective and may even damage the control unit in certain circumstances. Damage to the engine control unit resulting from chip tuning cannot be billed to AUDI AG under warranty. Owners should clarify with their tuning company in advance whether a software update is possible. Furthermore, neither AUDI AG nor its service partners can be held responsible for damage caused by the software update or for damage that occurs as the result of not having the update performed.

Warranty Information

For vehicles still under warranty, the software update described in TSB 2079998/1 is typically covered. However, if the vehicle is outside of any warranty, this Technical Service Bulletin is informational only, and any associated costs would be the owner's responsibility. All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual and are subject to review by Audi Warranty. When performing combined software updates, time stamps are not required for billing under warranty, allowing technicians to work on other vehicles simultaneously. This combined software update can also be performed by non-productive personnel.

Note for Technicians

It is crucial to reproduce the customer complaint, based on the description and cause of the issue, to ensure it can be clearly assigned to this TSB. This repair must only be carried out if all specified criteria, including model/type, chassis number, engine/motor and gearbox code, PR number(s), part number, and software version, apply exactly. Failure to meet these criteria may result in the solution not resolving the problem, necessitating repeat repairs, and potentially leading to a rejected warranty claim.

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Source: NHTSA ID: 10248231