Combined Charging Unit failure (2022 to 2024 cars)
The Combined Charging Unit handles AC and DC charging and feeds the high-voltage system. BMW bulletins say units on some 2022 to 2024 i4s may not have been built to specification and can leak coolant internally and fail, with symptoms from interrupted charging and no high-voltage readiness at start-up to the high-voltage system switching off while driving so the car coasts to a stop. A tiny recall (23V-449, 69 vehicles) covered badly assembled units. Replacement is free under warranty; we found no reliable out-of-warranty price.
How to check
Charge the car on both a Level 2 and a DC fast charger, check the history for charging or Drivetrain warnings, and ask a BMW dealer whether the charging unit has been replaced or updated.
