Audi A6/A7/A8/S8 (D5) 2017–2023 48V Alternator Control Board | OE No. 4N1903028

Description

Used 48V alternator control board specifically designed for Audi A8/S8 (D5) mild hybrid models, with the original equipment number 4N1903028.

Common Fault Symptoms

• 48V battery fails to charge normally

Part Number Details

• Manufacturer Part Number: —

• Vehicle OE Part Number: 4N1903028

• Compatible Part Numbers: 4N0903028 (all variants)

Product Condition & Notes

• Hardware Status: Refurbished and fully functional, pre-tested before shipment

• Post-Installation Requirement: Coding via ODIS diagnostic system is mandatory after mounting the board on the vehicle

Complete Installation & Activation Procedure

• Fully charge the vehicle's 12V auxiliary battery

• Turn on the ignition switch; the 48V battery should reach a 25% charge level

• Perform coding for the new alternator control board using ODIS

• Access the BMS (Battery Management System) to check real-time data:

  • If the 48V battery charge is below 10%, it requires external charging

  • If the charge drops below 5%, the battery will be locked by software; unlock it by entering pairing mode and disabling protection, then activate the battery

• Enter the diagnostic interface for Module 21 (Battery BMS), select access authorization, and input the login code 20103 to activate the system; the 48V high-voltage system will then go online

• If the 48V battery still cannot charge: Disconnect the 12V battery and use the diagnostic tool to reset all related control modules This part number 4N0903028P is applicable to a range of Audi models across different years and chassis types, specifically including the Audi A6 (C8, 2018–2023), Audi S6 (C8, 2019–2023), Audi RS6 (C8, 2019–2023), Audi A7 (4K8, 2018–2023), Audi S7 (4K8, 2019–2023), Audi RS7 (4K8, 2019–2023), Audi A8 (D5, 2017–2023), Audi S8 (D5, 2020–2023) and Audi Q8 (2019–2023).