2019-2026 Audi 12V Battery Drain TSB

Audi has issued Technical Service Bulletin (TSB) 27 23 62 2069747/5 for various 2019-2026 Audi models to address concerns regarding a drained 12V battery. This bulletin, revised on November 15, 2023, supersedes TSB 23-59 dated September 8, 2023. The TSB focuses on the documentation required before replacing a 12V battery that has been found to be drained, helping technicians identify the root cause, especially when external factors might be involved.

Symptoms of a Drained 12V Battery

The primary symptom addressed by this TSB is a vehicle's 12V battery being drained, leading to starting issues or other electrical malfunctions. Technicians are advised that if the 12V battery has to be replaced for any reason, specific diagnostic steps must be followed to determine the cause.

Important Warnings for Owners and Technicians

This TSB highlights several critical points regarding 12V battery maintenance and warranty claims:

• Warranty Exclusion: "Replacement of drained or damaged batteries due to external influence is not applicable to warranty and claims regarding such cases may be denied."
• Preventing External Drain: Owners should ensure the battery is not drained due to external influences. These include keeping the ignition on for a prolonged amount of time, parking the vehicle for over 90 days without a battery maintainer, or attaching non-OEM accessories that may draw electrical power while the vehicle is parked.
• Service Center Readiness: "Please ensure that the vehicle batteries are at an acceptable state of charge when the vehicle arrives at the service center."
• Long-Term Parking: "If the vehicle is parked for a prolonged amount of time (for example, waiting for parts), periodic (at least monthly) checks should be performed regarding the battery's state of charge."
• Immediate Recharge: "If the battery's state of charge is below 80%, the battery should be recharged immediately."
• Jump Starting for Charger: "In some cases, the battery may be too low to allow the battery charger to start up. In such cases, the charger can be started by 'jump starting' it by connecting jumper cables from a good battery to the damaged battery for a moment while the charger is connected. (The jumper cables only have to be touched to the poles as the vehicle charger needs to see an initial voltage to start up. They can be taken off as soon as the vehicle charger starts charging.)"

Diagnosis and Root Cause Analysis

To determine the root cause of an Audi 12V battery drained condition, technicians must gather additional information from the vehicle using the ODIS diagnostic system. This process is crucial before any battery replacement.

Initial Steps

1. Connect a 12V battery charger to the vehicle.
2. Perform the specified test plan within ODIS.

Reading History Data with ODIS

1. Navigate in ODIS to "GFF >> 19 - Diagnostics interface for databus >> Guided Functions >> Reading history data."
2. On the "Format selection" screen, choose option "-1- Display of the broken down data with the option to limit the period."
3. On the "Structured data" screen, input "1,2,3,4,5,6,7,8" to select specific history data points, then accept. These data points include static voltage shortfall, static current exceeded, shut-off stage history, battery replacement history, energy-critical vehicle states, energy balances of last trips, energy balances of last standing times, and history battery influence.
4. On the subsequent "Structured data" screen, enter the desired number of days for which history data should be printed out. Be aware that selecting too large a range may cause the test plan to fail.

Interpreting Battery History Data

ODIS will display the battery history data and store it in the GFF log. This data helps technicians identify if the drained battery was caused by misuse or external factors.

• Energy Critical Conditions (Section 5): This section reveals parameters active when the vehicle couldn't start due to a low 12V battery. Examples include the transmission being in Park, lights being on, or the ignition being left on while the battery was discharging.
• Energy Balance Standing (Section 7): This shows the duration the vehicle was parked and the corresponding battery discharge. The owner's manual states that customers are responsible for servicing (charging) the 12V battery if the vehicle is not driven for over one month. If the data shows a last standing time exceeding approximately 750 hours (about 31 days), combined with significant battery discharge and undervoltage, it suggests the battery may have been drained due to external influence.

Warranty Claim Procedure

Technicians should claim the GFF time required to perform this TSB on the warranty claim for the 12V battery replacement. This ensures proper documentation and processing of the repair.

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Source: NHTSA ID 10245616