2024-2025 BMW PHEV MIL with Fault Code 031BFC

Symptoms

Owners of certain 2024-2025 BMW Plug-in Hybrid Electric Vehicles (PHEV) may notice the Malfunction Indicator Lamp (MIL) illuminated on their dashboard. This warning is associated with an internal fault related to the AC charging electronics, specifically fault code 031BFC. Despite the warning, the AC charging system is expected to operate normally without any functional issues or charging complaints.

Fault Codes / DTCs

The primary fault code associated with this issue is:

• 031BFC: "AC charging, charging electronics 2, internal fault: No internal capacitor discharge stored in the CCU."

This code indicates a software-related issue within the Combined Charging Unit (CCU) rather than a hardware malfunction.

Diagnosis and Trigger Conditions

The Malfunction Indicator Lamp (MIL) and the fault code 031BFC are triggered by erroneous diagnostic parameters within the Combined Charging Unit (CCU) software. Specifically, the software's handling of the AC charging buffer capacitors' discharge function leads to the incorrect storage of fault code 031BFC. This occurs in affected PHEV vehicles equipped with CCU-03 (7.4 kW / 11 kW) and I-levels ranging from 24-07-500 to 25-11-5xx.

To diagnose, technicians should determine the vehicle's current I-level using applications like AIR or the Key Reader/Aftersales Workplace (AWP). If the I-level is below ...26-03-500, the issue may persist until a software update becomes available.

Important Warnings for Owners and Technicians

BMW Service Information Bulletin SIB 61 19 25 includes several critical advisories:

• "If AC charging is working as designed and there is not a charging complaint, exchanging the CCU will not eliminate the problem and is therefore not permitted."
• "Please inform the customer that there is no operational problem in the vehicle, and that a software update is expected in March 2026. The vehicle should be released back to the customer, and it should be documented in the repair order that the customer was informed of the situation."
• "If a customer refuses to pick up his/her vehicle, the area team should be contacted immediately. Vehicles should not sit at the BMW center awaiting the software update."
• "Do not replace any parts as it does not provide a remedy and is therefore not permitted."
• "Please do not proceed - the ISTA version with the update that corrects this software issue is expected to be available as of March 2026."
• "Until ISTA I-level ...26-03-500 is available, this issue (malfunction indicator lamp (MIL) and fault memory entry 031BFC) can occur multiple times."

Repair Procedure Summary

For vehicles exhibiting the BMW PHEV MIL fault 031BFC, the repair procedure outlined in SIB 61 19 25 is primarily informational and preventative, as a permanent software fix is pending. Technicians should:

1. Check I-level: Determine the vehicle's current I-level using the AIR or Key Reader/Aftersales Workplace (AWP) application.
2. Clear Fault Code: If the vehicle's I-level is lower than ...26-03-500, clear the fault code "031BFC".
3. Customer Communication: Inform the customer that there is no operational problem with the vehicle and that a software update is anticipated in March 2026. The vehicle should be released back to the customer, and this communication must be documented in the repair order.
4. No Parts Replacement: Do not replace any parts, including the Combined Charging Unit (CCU), as this will not resolve the software-related issue.

This bulletin, SIB 61 19 25, is considered both mobile-friendly and suitable for Remote Software Upgrade (RSU).

Owner Action

If your 2024-2025 BMW PHEV displays the Malfunction Indicator Lamp (MIL) and you suspect it's related to fault code 031BFC, you should schedule a service appointment with your authorized BMW dealer. The dealer will diagnose the issue, confirm it aligns with Service Information Bulletin SIB 61 19 25, and clear the fault code. You will be informed that the vehicle's AC charging system is functioning correctly despite the warning, and a permanent software update is expected around March 2026. This repair is covered under the BMW New Vehicle Limited Warranty and applicable State-specific Emissions Warranty.

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Source: NHTSA ID 11027771