2024-2025 Audi Q7 / Q8 48V Starter Generator DTCs P0A1A00 P19F800

Audi has issued Technical Service Bulletin (TSB) 2076994/1, released on February 25, 2025, to address concerns regarding the 48V Valeo starter generator (BSG) in certain 2024-2025 Audi Q7 and Q8 models. This TSB specifically targets diagnostic trouble codes (DTCs) P0A1A00 and P19F800, which can lead to an illuminated engine warning lamp and other related symptoms. The primary solution involves a software update to the vehicle's control units to resolve these Audi Q7 Q8 starter generator DTCs.

Symptoms

Owners of affected Audi Q7 and Q8 vehicles may notice the following symptoms:

• The "Engine warning lamp (MIL) is on" in the instrument cluster, as shown in Figure 1 of the TSB.
• Malfunction display symbols may appear, indicating a "vehicle electrical system malfunction indicator."
• A general loss of functionality related to the power supply or starter generator, described as "functionality -> no function" in workshop codes.

These symptoms are typically accompanied by specific diagnostic trouble codes stored in the vehicle's modules, pointing to an issue with the 48V starter generator system. If you are experiencing these issues with your Audi Q7 Q8 starter generator DTCs, a software update is likely needed.

Fault Codes / DTCs

Technicians may find the following diagnostic trouble codes stored in the vehicle's control modules:

Diagnostic Address	Diagnostic Trouble Code	Fault Symptom	Storage State
Engine Electronics	U046900	Invalid Data Received From Starter / Generator Control Module	static
Starter Generator	P19F800	48-volt vehicle electrical system not available	static
Engine Electronics	P0A1A00	Control module for alternator – Symptom 45888	static
Starter Generator	P19F800	48-volt vehicle electrical system not available – Symptom 38806	static

Diagnosis and Technical Background

The root cause for these diagnostic trouble codes and the associated symptoms is identified as an outdated software version within the Starter Generator (C29) control unit. This can lead to communication issues or incorrect operation of the 48V system, resulting in the illumination of the engine warning lamp.

Audi has implemented new software in production week 07/2025 to address this issue in newly manufactured vehicles. For existing vehicles, a software update is required.

Repair Procedure Summary

This Technical Service Bulletin (TSB) 2076994/1 closes PSS 2076029, which also addressed the 27 PSS Valeo 48V Starter Generator (BSG) DTCs P0A1A00 and P19F800. The repair involves updating the software for the Engine Electronics (J623) control unit.

Technicians should follow all instructions outlined in TSB 2011732, titled "00 Software Version Management (SVM), operating instructions." The update is performed using the SVM action code CCA005. The software part number for the Starter Generator (00CC) is 4M0.903.028. The update will change the software version from 0606 to 0608 or higher.

Warranty Information

Warranty claims related to this TSB must be submitted in accordance with the Audi Warranty Policies and Procedures Manual. The specific details for claiming this repair are:

• Service Number: 2726
• Damage Code: 0039
• Labor Operations:
  • Software Update: 0151 0010 (See SRT with associated operations)
  • Software Update: 0151 0060 (Time stated on the diagnostic protocol)
• Claim Comment: As per TSB 2076029/1

If the vehicle is outside of its warranty period, this Technical Service Bulletin is for informational purposes only.

Important Warnings for Owners

Audi provides several important advisories for vehicle owners regarding this software update:

• Software Modifications: If you or a third party have modified your vehicle's software (e.g., chip tuning or retrofitting), be aware that this software update may neutralize those previous modifications. Audi recommends referring to your Warranty and Maintenance booklet for information on how such modifications can impact warranty coverage.
• Declining the Update: If you choose to decline the software update, be informed that this could lead to further issues or restrictions with the use of your vehicle or individual components. Your dealer will make a note of this on the repair order before it is signed.
• Customer Communication: Dealers are instructed to inform customers about the software update and inquire about any third-party software modifications.

This TSB ensures that your 2024-2025 Audi Q7 or Q8 operates correctly and resolves the Audi Q7 Q8 starter generator DTCs by updating the necessary control unit software.

NHTSA ID: 2076994/1