2021-2024 Audi U142100 U164200 Communication DTCs

Audi has issued Technical Service Bulletin (TSB) 91 24 63 2075537/1 to address instances where diagnostic trouble codes (DTCs) U142100 and U164200 may be stored as passive or sporadic entries in the data bus diagnostic interface -J533-. This TSB, dated October 8, 2024, clarifies that for 2021-2024 Audi vehicles, these specific communication faults often do not indicate a functional problem and typically do not require repair.

Symptoms

Technicians may find the following DTCs and symptom code(s) stored in the data bus diagnostic interface -J533- (address word 0075) during vehicle diagnosis:

Fault Codes / DTCs

Code	Description	Module
U142100	Control module for emergency call module and communication unit no communication – passive / sporadic	data bus diagnostic interface -J533-
U164200	Ethernet Emergency Call Module no communication - passive / sporadic	data bus diagnostic interface -J533-

Diagnosis / Trigger Conditions

These passive and sporadic DTCs, including Audi U142100 U164200, are typically stored due to the control module's start-up behavior. They can also occur because of the variable time required for the ConBox -J949- (emergency call module and communication unit) to connect to the mobile network. It is crucial to note that this service information is only valid if these two DTCs are logged as sporadic.

If the event memory entries for U142100 and U164200 are logged as static, technicians must follow the instructions provided in the Guided Fault Finding (GFF) system for proper diagnosis and repair.

Important Warnings for Owners and Technicians

Audi explicitly states that for sporadic instances of these DTCs, there is no reason to attempt any repairs. The TSB includes the following critical advisories:

• "This service info is only valid if these two DTCs are logged as sporadic."
• "If the two event memory entries are logged as static, please follow the instructions in Guided Fault Finding (GFF)."
• "Replacing emergency call module control unit and communication unit J949 or data bus diagnostic interface J533 will not lead to a solution either."
• "Invoicing under warranty is not permitted. Unjustified work/replacement parts will be charged back."

What Owners Should Know

If your 2021-2024 Audi vehicle has sporadic U142100 or U164200 DTCs, these codes typically do not affect the functioning of the vehicle or the emergency call module control unit and communication unit J949. DTCs that can be safely ignored are usually marked with a yellow triangle in the vehicle diagnostic tester, indicating their non-critical nature. Therefore, if these codes are sporadic, no action is required on your part, and no repairs should be performed.

Production Updates

Audi plans to incorporate robustness measures into new control unit versions starting from Model Year 2025 onwards. This update aims to mitigate the conditions that lead to the storage of these sporadic DTCs.

Owner Action

If you encounter a diagnostic report showing Audi U142100 U164200 DTCs, ensure your service center confirms they are sporadic. If they are, no repair is necessary, and you should not be charged for any diagnostic or repair attempts related to these specific codes. This TSB (reference 2075537) is informational and does not apply to any Audi Warranty claims for this condition.

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Source: NHTSA ID: 11009958