2025 Audi A5/Q5 Drive System Fault P066700 TSB

Audi has released Technical Service Bulletin (TSB) 2080075/3 to address a specific drive system fault affecting certain 2025 Audi A5, S5, Q5, and SQ5 models. This bulletin provides comprehensive guidance for technicians to diagnose and resolve instances where a "drive system fault" warning appears in the instrument cluster, typically alongside a specific diagnostic trouble code.

The primary solution outlined in TSB 2080075/3 involves performing a software update to the vehicle's transmission electronics control unit, identified as J217. This update aims to optimize the system's performance and prevent the recurrence of the fault condition.

Symptoms of a Drive System Fault

Owners of affected 2025 Audi A5, S5, Q5, or SQ5 vehicles may observe a prominent warning message in their instrument cluster. The most common symptom reported is the illumination of the "drive system fault warning lamp lights up in the dash panel insert." This visual alert indicates a potential issue within the vehicle's powertrain or transmission system.

While some owners may directly report this warning, the fault can also be identified by technicians through an event memory entry in the gearbox electronics control unit J217, even if there isn't a direct customer complaint about a specific driving issue. The presence of this warning light signals that the vehicle's internal diagnostics have detected a condition requiring attention.

Diagnostic Trouble Code P066700

When a technician investigates the "drive system fault" warning, they will typically find a specific diagnostic trouble code (DTC) logged in the transmission electronics control unit - J217- (diagnostic address 0002). The relevant code for this issue is:

Code	Description	Symptom Code	Module
P066700	"PCM/ECM/TCM Internal Temperature Sensor 'A' Range/Performance"	20752	J217 (Transmission Electronics Control Unit)

This DTC, P066700, specifically points to a performance or range issue with the internal temperature sensor within the Powertrain Control Module (PCM), Engine Control Module (ECM), or Transmission Control Module (TCM). The accompanying symptom code 20752 further defines the specific nature of this sensor's malfunction, contributing to the overall 2025 Audi A5 drive system fault.

Diagnosis and Trigger Conditions

For technicians, diagnosing this particular 2025 Audi A5 drive system fault involves confirming the presence of the P066700 DTC and symptom code 20752 within the J217 control unit. The TSB emphasizes the importance of accurately reproducing the customer complaint or verifying the fault conditions before proceeding with any repairs. This ensures that the recommended solution directly addresses the identified problem.

Audi's production solution for this issue involves optimized software, which was implemented in vehicles manufactured from week 36/25 onwards. This suggests that vehicles produced after this period should already incorporate the necessary software improvements to prevent this specific fault.

Important Warnings for Owners and Technicians

Audi provides critical warnings regarding the application of this Technical Service Bulletin 2080075/3:

• "Try to reproduce the customer complaint (based on the description/cause of the issue), so that it can be clearly assigned to this TSB. The following repair must only be carried out if all the criteria (model/type, chassis number, engine/motor, gearbox code, PR number(s), part number, software version, code, etc.) apply exactly. Otherwise, this solution will not eliminate the problem and repeat repairs may be necessary. In such a case, the warranty claim may be rejected, and the cost of the parts may be charged back."
• "If the customer declines the software update, please inform them that this could lead to issues or restrictions with the use of the vehicle or individual components."

These warnings highlight the necessity of precise diagnosis and adherence to the TSB's guidelines to ensure an effective repair and avoid potential warranty claim rejections. Owners should be aware that declining the recommended software update could impact their vehicle's functionality.

Repair Procedure Summary: Software Update

The primary repair for the 2025 Audi A5 drive system fault, as detailed in TSB 2080075/3, is a software update. This is not a standalone procedure but refers to another specific Technical Service Bulletin, TSB 2079690, titled "00 Combined software update 03.10.00/c (28.13.01) KD2." This indicates that the repair involves a comprehensive software update that may affect multiple control units within the vehicle, not just the J217 transmission module.

Technicians are instructed to perform this combined software update, which includes connecting a battery charger to maintain stable voltage throughout the process. The update ensures that all relevant control units are running the latest optimized software, addressing the root cause of the P066700 DTC and the "drive system fault" warning.

Warranty Information

For vehicles still under warranty, Audi outlines specific procedures for claiming the repair under TSB 2080075/3. The service number associated with this repair is 3410, and the damage code is KD02. The labor operations and their corresponding time units (TU) are as follows:

• 0151 0010: Software update, including connecting battery charger. This operation is typically associated with specific SRT (Standard Repair Time) guidelines.
• 0151 0040: Fixed rate for the complete software update process, encompassing all necessary preliminary and follow-up work. This includes crucial steps such as bus sleep cycle management, calibration drives, and any additional required tasks. This operation is allotted 130 TU.
• 0150 9999: An additional lump sum of 50 TU is available for cases involving flash cancellation, which may occur during additional repair attempts.

It is important to note that if a vehicle is outside of its warranty period, this Technical Service Bulletin serves as informational guidance only. All warranty claims must comply with the Audi Warranty Policies and Procedures Manual and are subject to review or audit by Audi Warranty. When performing combined software updates, time stamps are not required for billing under warranty, allowing technicians flexibility in their work schedule.

Additional Information for Owners

Owners should be aware that the software update described in TSB 2080075/3 may involve updating multiple control units to ensure proper communication and function. If the vehicle's software has been previously modified by the owner or third parties (e.g., tuning or retrofitting), the Audi service department will inform the customer that this software update may neutralize those previous modifications. It is crucial to understand these implications before proceeding with the update.

If an owner chooses to decline the software update, they will be informed that this decision could lead to ongoing issues or restrictions concerning the use of the vehicle or its individual components. Therefore, it is strongly recommended to proceed with the software update to fully resolve the 2025 Audi A5 drive system fault and ensure optimal vehicle performance and safety.

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Source: NHTSA ID: 11028474