DC/DC Converter Electrical Connection May Corrode

Affected vehicles (1)

Component / system

Defect

BMW of North America, LLC (BMW) is recalling certain 2017-2018 C Evolution motorcycles. The front wheel may splash water onto the electrical plug connection of the DC/DC converter's 12V battery ground cable lug, resulting in corrosion of the electrical contacts.

Risk / consequence

Corrosion on the electrical contacts may cause overheating, increasing the risk of a fire.

Remedy

Dealers will replace the cable section with the ground cable lug with a repair cable kit, free of charge. In addition, the 12V plug connector to the DC/DC converter will be checked; if contact corrosion is found to be present, additional sections of the wiring harness will be replaced, free of charge. Owner notification letters are expected to be mailed July 6, 2026. Owners may contact BMW customer service at 1-800-525-7417. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning July 6, 2026.

Chronology of events

1. Jun 26, 2025

   On June 26, 2025, BMW became aware of a thermal event in a non-US market involving a Model Year 2020 BMW C evolution. An engineering investigation was initiated. Attention was focused on the connection between the 12V battery and DC/DC converter. Parts from this vehicle were requested to be returned for analysis.

2. Jul 16, 2025

   On July 16, 2025, an additional thermal event in a non-US market was reported involving a Model Year 2016 BMW C evolution. Access to this vehicle or vehicle parts was not possible. Following the initial report, and prior to receipt of the parts, detailed engineering investigations were conducted. The 12V plug connector leading from the board net battery (12V battery) to the DC/DC converter (inside the high-voltage traction battery housing) was identified as a starting point. High- voltage components were not deemed to be an issue and, therefore, were excluded. Further field case analysis suggested that this 12V connector could be susceptible to internal corrosion due to water ingress in certain specific, but yet-to-be-identified, instances. An initial root cause hypothesis, based upon the geometry of the high-voltage battery housing (in which water could contact the connector), was formulated and tested. However, testing and field data analysis disproved this hypothesis. Additional analyses indicated that under unfavorable circumstances, splash water from the front wheel could reach the ground cable lug on the front part of the battery housing. If the cable lug was not sufficiently sealed, then small amounts of water could seep along the cable due to capillary action and reach the connector plug.

3. May 7, 2026

   On May 7, 2026, BMW decided to conduct a voluntary safety recall. BMW has not received any reports, nor is BMW otherwise aware, of any accidents or injuries related to this issue.

Notification schedule

Dealer notification

May 21, 2026 - May 21, 2026 No Dealers

Owner notification

Jul 06, 2026 - Jul 06, 2026 Phased Recall