2023-2024 Audi Engine Start System Fault B200047 TSB

Owners of certain 2023-2024 Audi models may encounter an "Engine start system: fault" or "Power unit start system: fault" message displayed in their instrument cluster. While these messages appear, Audi notes that there are typically no functional issues with the vehicle's operation. This issue is addressed by Audi Technical Service Bulletin (TSB) 2071735/2, which supersedes a previous bulletin, 23-17, dated October 12, 2023.

The TSB identifies a specific diagnostic trouble code (DTC) that technicians may find when diagnosing this condition. The root cause is a software anomaly within the Comfort Control Module -J393-.

Symptoms

Owners will primarily notice one of the following messages appearing in the instrument cluster:

• "Engine start system: fault"
• "Power unit start system: fault"

Despite these warnings, the vehicle's engine start system or power unit typically functions without any actual problems.

Fault Codes / DTCs

When diagnosing the reported warning messages, technicians are likely to find the following diagnostic trouble code (DTC) stored in the Comfort Control Module -J393- (address word 0046):

Code	Description	Symptom Code	Module
B200047	Control Module Faulty	65552	Comfort Control Module -J393-

This DTC indicates an internal fault within the control module, which is resolved by updating its software.

Technical Background

The underlying cause of the "Audi Engine Start System Fault B200047" is a software issue residing within the Comfort Control Module -J393-. This module is responsible for various functions, and a specific software bug can trigger the erroneous fault message and DTC B200047.

Repair Procedure Summary

The resolution for the "Audi Engine Start System Fault B200047" involves updating the software of the Comfort Control Module -J393-. This is performed using the Software Version Management (SVM) system. Technicians should follow the instructions outlined in TSB 2011732, which details the SVM operating procedures.

Specifically, the Comfort Control Module -J393- (address word 0046) needs to be updated with the latest software version. The TSB specifies the following software details:

Model Group	Diagnostic Address	Old Software Part Number	Old Software Version	New Software Part Number (or higher)	New Software Version (or higher)	SVM Code Input
A4, A5, Q7, Q8, e-tron	0046	8W1.907.064.*	0627	8W1.907.064.*	0628	46A034

This update ensures the module operates with the corrected software, preventing the erroneous fault messages and DTC B200047 from appearing.

Important Warnings

During the software update process, it is critical to ensure the vehicle's key is correctly positioned. The TSB explicitly states:

• "The key must be on the emergency reader coil during the update."

Failure to follow this instruction could interrupt the update process or lead to further complications.

Owner Action

If you own a 2023-2024 Audi model and are experiencing the "Engine start system: fault" or "Power unit start system: fault" message, you should contact your authorized Audi dealership. Explain the symptoms you are observing and mention the possibility of a software update related to TSB 2071735/2 and DTC B200047. The dealership will diagnose the issue and perform the necessary software update on the Comfort Control Module -J393-.

This repair is typically covered under warranty for vehicles up to 48 months or 50,000 miles. For Audi Certified Pre-Owned (CPO) vehicles, the repair is covered under the G10 claim type, subject to owner verification. If your vehicle is outside of warranty, this Technical Service Bulletin serves as informational guidance, and costs may apply. The service number for this procedure is 5789, with damage code 0039.

NHTSA ID: 10244500