2021-2024 Audi Q5 e High-Voltage Battery Deterioration TSB

Owners of 2021, 2023, and 2024 Audi Q5 e Plug-in Hybrid Electric Vehicles (PHEV) may encounter an illuminated Malfunction Indicator Lamp (MIL) or an "emissions control system malfunction display" message. This condition is often linked to deterioration within one or more high-voltage battery modules. Audi has released Technical Service Bulletin (TSB) 2079556/1 to provide dealerships with diagnostic and repair guidance for this specific issue, ensuring proper resolution for the Audi Q5 e high-voltage battery deterioration. This TSB, identified as 2079556/1, was released for publishing on September 30, 2025, and specifically addresses diagnostic trouble codes related to the hybrid battery management system (diagnostic address 008C). It applies to vehicles sold in the United States market and is classified at an 'EH' level. This bulletin provides a structured approach for technicians to identify and rectify the underlying problem.

Symptoms of High-Voltage Battery Deterioration

The primary symptom owners will notice is the illumination of the Malfunction Indicator Lamp (MIL) on the instrument cluster. This warning light signals that the vehicle's onboard diagnostic system has detected a fault within the emissions control system. In addition to the MIL light, drivers might also see an "emissions control system malfunction display" message. These indicators point to an underlying issue with the hybrid system, specifically concerning the high-voltage battery's health and performance. If you experience these warnings, it's crucial to have your Audi Q5 e inspected by a qualified service center to address the potential Audi Q5 e high-voltage battery deterioration.

Diagnostic Trouble Codes (DTCs)

When the Audi Q5 e high-voltage battery deterioration occurs, the vehicle's hybrid battery management control unit (diagnostic address 008C) will log specific diagnostic trouble codes. These codes pinpoint which particular high-voltage battery group is experiencing deterioration. The TSB lists several DTCs, which can be stored as either intermittent (passive) or static (active) faults, all indicating a 'Deterioration' fault symptom within the hybrid/EV battery pack. The affected control module is consistently identified as '008C - Hybrid battery management'.

Diagnostic Trouble Code	Description	Storage State
P0A7F00	Hybrid/EV Battery Pack "A" Deterioration	Intermittent/Static
P0EDD00	Hybrid/EV Battery Pack "B" Deterioration	Intermittent/Static
P0EDE00	Hybrid/EV Battery Pack "C" Deterioration	Intermittent/Static
P0EDF00	Hybrid/EV Battery Pack "D" Deterioration	Intermittent/Static
P0EE000	Hybrid/EV Battery Pack "E" Deterioration	Intermittent/Static
P0EE100	Hybrid/EV Battery Pack "F" Deterioration	Intermittent/Static
P2CCC00	Hybrid/EV Battery Pack "G" Deterioration	Intermittent/Static
P2CCD00	Hybrid/EV Battery Pack "H" Deterioration	Intermittent/Static

These codes indicate that one or more of the high-voltage battery groups (labeled A through H) are not performing within expected parameters due to deterioration. An intermittent fault means the condition occurred but is not currently present, while a static fault indicates the condition is currently active.

Diagnosis and Trigger Conditions

For a technician to confirm the Audi Q5 e high-voltage battery deterioration issue, several conditions must be met. First, the customer's reported concern, such as the MIL light being on, must be reproducible. This ensures that the problem is actively present or can be triggered under specific conditions. Next, a Guided Fault Finding (GFF) procedure must be performed. In cases related to this TSB 2079556/1, the GFF might not provide any immediate recommended actions, which is a key indicator for technicians to proceed with further investigation. The critical diagnostic step is to check the event memory entries within the hybrid battery management control unit (diagnostic address 008C). The presence of any of the listed DTCs (P0A7F00, P0EDD00, P0EDE00, P0EDF00, P0EE000, P0EE100, P2CCC00, P2CCD00), whether intermittent or static, confirms the condition described in TSB 2079556/1. This diagnostic process is essential to accurately identify the specific battery module requiring attention.

Repair Procedure Summary

The repair for the Audi Q5 e high-voltage battery deterioration primarily involves the replacement of the faulty high-voltage battery module(s). The process begins with accurately identifying the specific battery module that has deteriorated, which is determined by the diagnostic trouble code logged in the hybrid battery management system. Once the affected module is identified, it must be replaced according to the detailed instructions provided in the official Audi Workshop Manuals. These manuals contain precise steps for safely de-energizing the high-voltage system, removing the old module, installing the new one, and re-commissioning the system. Technicians are advised to consult these manuals for all specific procedures, including torque specifications and any components that require replacement during the repair, such as fasteners, bolts, nuts, and screws. This ensures the integrity and safety of the high-voltage system after the repair. It is important to note a specific instruction from TSB 2079556/1: if diagnostic findings indicate that more than two high-voltage battery modules are causing the customer's complaint, the dealership must submit a ticket with the Technical Assistance Center (TAC) or a TAC Web ticket before initiating any repair work. This step ensures that complex cases receive appropriate guidance and support from Audi's technical experts and prevents unnecessary replacement of multiple modules without prior approval.

Warranty Information and Service Codes

Audi has provided specific guidelines for warranty claims related to this Audi Q5 e high-voltage battery deterioration issue. All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual and are subject to review or audit by Audi Warranty. The Claim Type for this repair is standard, but the TSB explicitly states that if the vehicle is outside of any warranty, this Technical Service Bulletin is informational only. This means that out-of-warranty repairs may not be covered by Audi and could incur costs for the owner. For service operations, the TSB specifies the following codes and associated Standard Repair Times (SRT):

• Labor Operation 0040: This code covers the 'Remove and install high-voltage battery module'. The associated SRT is 9301 19xx, which refers to the time specified in the SRT catalog for associated operations. This ensures technicians are compensated accurately for the labor involved in handling high-voltage components.
• Labor Operation GFF: This code is for the 'Guided Fault Finding' procedure. The SRT for this operation is 0150 0060, with the time stated on the diagnostic protocol. This covers the diagnostic time spent identifying the fault.

The Claim Comment for these operations should explicitly state: "As per TSB 2079556/1". This ensures that the claim is correctly linked to the bulletin and processed efficiently. The Service Number associated with this bulletin for warranty purposes is 9301.

Important Warnings for Owners

Owners should be aware of critical information regarding this Technical Service Bulletin (TSB) 2079556/1. The TSB explicitly states that "If the vehicle is outside of any warranty, this Technical Service Bulletin is informational only." This means that if your 2021, 2023, or 2024 Audi Q5 e is no longer under warranty, the repair for the high-voltage battery deterioration may not be covered by Audi, and you could be responsible for the full cost of diagnosis and replacement. Furthermore, the bulletin advises that "All part and service references provided in this TSB (2079556) are subject to change and/or removal. Always check with your Parts Department and/or ETKA for the latest information and parts bulletins. Please check the Repair Manual for fasteners, bolts, nuts, and screws that require replacement during the repair." While this instruction is primarily for technicians, it highlights that specific part numbers or procedures might evolve. Owners should always consult with an authorized Audi dealership to confirm their vehicle's warranty status and to get the most current information regarding parts and labor for any repairs related to the Audi Q5 e high-voltage battery deterioration.

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NHTSA ID: 11023828