2022-2024 Audi Drained 12V Battery Diagnosis TSB

Symptoms

Owners of 2022-2024 Audi vehicles may experience issues related to a drained 12V battery. Common complaints include the vehicle not starting and the ignition being unable to turn on. For example, an Audi e-tron drained battery can prevent the vehicle from powering up.

Technicians investigating these issues often find multiple low voltage Diagnostic Trouble Codes (DTCs) stored across various vehicle modules. Additionally, the 12V battery may test as defective when evaluated with a GRX-3000 tool.

Important Warnings for Owners

Audi has issued specific notices regarding conditions that can lead to a drained 12V battery and potentially affect warranty claims:

• "Please make sure that the battery is not drained due to external influence: - Keeping the ignition on for a prolonged amount of time. - Parking the vehicle for a prolonged amount of time without a battery maintainer being attached (>90 days). – Non-OEM accessories being attached to the vehicle that may use electrical power while the vehicle is parked. - Replacement of drained or damaged batteries due to external influence is not applicable to warranty and claims regarding such cases may be denied."
• "Please make sure that vehicle batteries are at an acceptable state of charge when the vehicle arrives at the service center. If a 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. If the battery's state of charge is below 80%, the battery should be recharged immediately."
• "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 jumpstarting" it by connecting jumper cables from a good battery to the damaged battery for a moment while the charger is connected."

These warnings highlight the importance of proper vehicle care and maintenance to prevent an Audi e-tron drained battery and ensure warranty coverage.

Diagnosis and Repair Procedure Summary

Before replacing a 12V battery in an affected Audi, technicians must perform one of two diagnostic procedures to gather data and identify the root cause of the drain. This ensures that a new battery isn't installed without addressing underlying issues.

Method 1: When the old battery can keep ignition active for a short period

If the vehicle's ignition can still be turned on, even briefly, technicians will use the ODIS diagnostic system to perform a specific test plan:

• Navigate to GFF -> select self-test -> 27 Group -> Electrical Components -> A Battery testing.

Method 2: When the old battery cannot keep ignition active or the vehicle doesn't turn on

If the 12V battery is too low to activate the ignition, the technician will first connect a 12V battery charger. If the battery is so drained that the charger won't start, a temporary jumpstart from a good battery may be needed to initiate the charging process. Once charging, the technician will perform a different ODIS test plan:

• Navigate to GFF -> 19 - Diagnostics interface for databus -> Guided Functions -> Reading history data, then select Option 1 (all).

After either method is completed and the necessary data is read, the GFF log must be uploaded to the paperless system. This data helps Audi understand the cause of the Audi e-tron drained battery and supports future improvements.

Warranty Information

For warranty claims related to 12V battery replacement, the time spent performing the Guided Fault Finding (GFF) diagnostic procedures outlined in this TSB should be claimed on the same warranty claim as the battery replacement itself.

Source: NHTSA ID 10233376