Technical Service Bulletin B120523 — 2022 BMW I4

The customer states there is a Drivetrain Malfunction message displayed in the instrument cluster. In addition, the following fault memory entries are saved in the CCU (Combined Charging Unit): 0317F2 - High-voltage system, insulation fault detected: when switch contactors are closed. 0317F1 - High-voltage system, insulation resistance below warning threshold: when switch contactors are closed. The fault memory entries (isolation faults) can occur both individually and in combination, and must be traced back to the eDrive motor based on the ISTA test procedure. If the ISTA test procedure lists the possible cause of fault as “a metal chip is found behind the brush module” (between the brush module and the end shield of the electrical machine), then a repair is required. Refer to service solution no. 20000794435083 in Aftersales Information Research (AIR). Follow information in the Procedure section below