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U0469: Invalid Data Received From Starter/Generator Control Module

Severity: high

What it means: A network code that means the engine computer or gateway got bad data from the starter/generator control module. On Audis with the 48V mild-hybrid system, Audi bulletin 2058831 ties U046900 to the 'Electrical system: Malfunction' warning, where a hardware issue can stop the belt starter generator (BSG) from working.

Safe to drive? No. On affected Audis, the 48V failure can cascade into more warnings and shut the car down within miles. Get to a safe place and arrange a tow.

Common symptoms

Likely causes, ranked

  1. Failed 48V belt starter generatorShop
  2. Low 48V or 12V battery chargeShop
  3. Wiring or network faultShop
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Vehicle-specific notes

  • 2019–2023 Audi Q8: Audi bulletin 2058831 covers the 48V Electrical system: Malfunction warning with U046900 on 2019-2023 Q8, A6, A7 and A8 and 2020-2023 Q7 and A6 allroad. Read the full answer · Source

DIY or shop?

Not DIY. Audi requires its ODIS tester to diagnose the 48V system.

Before you replace parts

  1. Get off the road safely when the warning appears.
  2. Ask the dealer about Audi bulletin 2058831.
  3. Ask whether your VIN is covered by any 48V starter-generator campaign or extended coverage.
  4. Make sure both batteries are tested.

Safety / mechanic note

Verify with a mechanic. A sudden shutdown in traffic is a crash risk. A code points to a circuit or system, not always a specific part.

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Sources