2024 Audi Q5/Q8 e-tron 12V Battery Discharged TSB 2074126/1

Audi has released Technical Service Bulletin (TSB) 2074126/1 to address concerns regarding the 12V battery discharging in certain 2024 Audi Q5 and Q8 e-tron models. This issue, described as a "12V battery discharged by bus wake-up," is attributed to a software problem within the High-voltage Battery Charger Control Module.

This TSB applies specifically to 2024 Audi Q5, Q5 e quattro, Q5 Sportback, SQ5 Sportback, Q8 e-tron, SQ8 e-tron, Q8 Sportback e-tron, and SQ8 Sportback e-tron vehicles. While a permanent fix is still under development, Audi has provided a temporary workaround for affected vehicles.

Symptoms

Owners of affected 2024 Audi Q5 and Q8 e-tron vehicles may experience the following symptoms related to the 12V battery:

• "Battery failure at PDI according to ODIS new vehicle battery test plan."
• "12V battery discharged after a stationary period."

These symptoms point to an unexpected drain on the 12V battery, particularly when the vehicle is not in use.

Technical Background

The root cause of the 2024 Audi Q5 12V battery discharged issue is a software problem within the High-voltage Battery Charger Control Module, which is identified by diagnostic address 00C6. This module, manufactured by Kostal (Gen3), is responsible for managing the high-voltage battery charging process.

For Q5 PHEV models, the affected hardware part number is 9Y0915681 A/B/C/D, with software version 3310. For Q8 e-tron models, the affected hardware part number is 9J1915684 B/N, with software versions 3112 and 3115.

Important Warnings for Owners and Technicians

Audi has provided critical guidance regarding this condition:

• "Explain to the customer that a solution is expected to be available by the end of the 1st quarter of 2025 (subject to change) and that no repairs are necessary at this point. Do not replace any components for this condition since this will not resolve the customer's concern."
• "A terminal 30 reset causes the settings to be reset and the procedure must be repeated."

This means owners should not seek component replacements for this issue, as it will not resolve the underlying software problem. Any temporary settings applied as a workaround will be lost if a terminal 30 reset occurs, requiring the procedure to be repeated.

Temporary Workaround

To prevent the 2024 Audi Q5 12V battery discharged issue from recurring, Audi recommends a temporary workaround involving adjustments through the MMI system. The steps vary slightly depending on whether you have a Q5 PHEV or a Q8 e-tron.

For Q5 PHEV Models

1. With the ignition on, select the “VEHICLE" tile on the MMI screen.
2. Select the “Air conditioning" tile.
3. Choose “Auxiliary air conditioning."
4. Locate and select an active timer.
5. Turn the timer off.
6. Return to the main menu.

For Q8 e-tron Models

1. Select the charging symbol located in the lower MMI screen.
2. Select the clock symbol, which will take you to the charging menu.
3. Activate a charging timer.
4. Select the clock symbol again to activate the timer.
5. Deactivate the time selected in step 4.
6. Return to the main menu.

Production Solution

Audi states that a permanent solution for the 2024 Audi Q5 12V battery discharged problem is currently under development. The company expects to update this bulletin when more information regarding the fix becomes available, with a solution anticipated by the end of the first quarter of 2025.

Warranty Information

This Technical Service Bulletin (TSB 2074126/1) outlines specific warranty claim procedures. The claim type is 110, applicable for vehicles up to 48 months or 50,000 miles. For CPO (Certified Pre-Owned) covered vehicles, the claim type is G10, requiring owner verification. If the vehicle is outside of any warranty coverage, this TSB serves as informational guidance only.

The service number associated with this procedure is 9352, with a damage code of 0039. Labor operations include 9352 1599 for setting the high-voltage charging unit, with a time allowance of 10 TU (Technical Units). Diagnostic times are allocated for GFF / Guided Functions, specifically 0150 0060 and 0150 0010.

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Source: NHTSA ID: 11002931, TSB ID: 2074126/1