2021-2023 Audi e-tron Red Electrical System Fault TSB 93 24 07 2074900/1

Important Warnings for Owners

Audi has issued a critical advisory regarding this electrical system fault. Owners should be aware of the following:

• Do not replace components: For the condition described in TSB 93 24 07 2074900/1, Audi explicitly states: "Do not replace any components for this condition since this will not resolve the customer's concern." A permanent solution is still under development.
• Solution timeline: Information on the availability of a planned solution is expected by the end of the 4th quarter of 2024, though this timeline is subject to change.

Symptoms of the Audi e-tron Red Electrical System Fault

Owners of 2021-2023 Audi e-tron and e-tron Sportback vehicles may experience a red electrical system fault in the instrument cluster. This is typically accompanied by a specific warning message and can prevent the vehicle from starting.

Common symptoms include:

• A red electrical system warning light appearing in the instrument cluster.
• The verbatim message: "Electrical system: fault. Safely stop vehicle".
• The vehicle being unable to start.

Fault Codes (DTCs)

When diagnosing the Audi e-tron red electrical system fault, technicians may find specific Diagnostic Trouble Codes (DTCs) stored in the hybrid battery management control unit (J840, address word 008C).

The primary DTC associated with this TSB is:

Code	Description	Module
P0AC000	Hybrid/EV Battery Pack Current Sensor “A” Circuit Range/Performance	J840

It is important to note that for this specific condition, the following related DTCs are explicitly stated as not being logged:

• P0AA700: Hybrid/EV Battery Voltage Isolation sensor Circuit.
• P0AA100: Hybrid Battery Positive Contact Circuit Stuck Closed.
• P0AA200: Hybrid/EV Battery Positive Contactor Circuit Stuck Open.
• P0AA400: Hybrid/EV Battery Negative Contact Circuit Stuck Closed.
• P0AA500: Hybrid/EV Battery Negative Contact Circuit Stuck Open.

Another related DTC, P0B1500 (Hybrid/EV Battery Pack Voltage Sense “B” Circuit Range/Performance), is also mentioned in the technical background as potentially relevant to battery pack voltage sensing issues.

Diagnosis and Trigger Conditions

The Audi e-tron red electrical system fault is typically triggered by a specific condition related to the hybrid/EV battery pack current sensor. The fault is reproducible, meaning it can be observed by technicians. The presence of DTC P0AC000 in the J840 hybrid battery management control unit is a key diagnostic indicator. The absence of the P0AAxxx series of DTCs helps differentiate this specific issue from other battery contactor or isolation faults.

Interim Repair Procedure Summary

Since a permanent production solution for the Audi e-tron red electrical system fault is still under development, Audi has provided an interim diagnostic and assessment procedure under TSB 93 24 07 2074900/1. This procedure is designed to re-assess the issue and gather further information if the complaint persists.

The steps involve:

1. Activate Bus Sleep Mode: The vehicle's electrical system is put into a low-power state.
2. Lock the Vehicle: The vehicle must be locked, ensuring that no electrical equipment is active and the contactors are open. The vehicle should also not be connected to a charger during this time.
3. Erase DTCs: After the bus sleep cycle is complete, all stored Diagnostic Trouble Codes (DTCs) are to be erased.
4. Re-assessment: Following these steps, the vehicle is re-assessed to determine if the electrical system fault still occurs.

If the complaint about the Audi e-tron red electrical system fault persists after this procedure, technicians are instructed to submit a Technical Assistance Center (TAC) web ticket, referencing the TSB number in the customer comments section to expedite the process.

What Owners Should Know

If your 2021-2023 Audi e-tron is displaying a red electrical system fault and the message "Electrical system: fault. Safely stop vehicle", it is important to understand the current situation. Audi is actively working on a permanent solution, which is anticipated by the end of 2024. In the meantime, the manufacturer advises against replacing any components for this specific condition, as it will not resolve the underlying issue. Your dealer will follow the diagnostic steps outlined in TSB 93 24 07 2074900/1 to assess the fault and provide feedback to Audi's technical teams. There is no cost to the owner for this diagnostic work under warranty.

NHTSA ID

Source: NHTSA ID: 11007357