2022-2025 BMW i4, i5, i7 Electric Auxiliary Heater Failure

BMW has released Service Information Bulletin SIB 64 09 25, dated December 22, 2025, to address an issue with the electric auxiliary heater in certain 2022-2025 i4, i5, and i7 electric vehicles. This bulletin, which is Revision 01 and supersedes SI B64 09 25 dated August 2025, outlines the procedure for correcting a potential fault that could lead to a non-functional electric auxiliary heater.

The campaign code for this service action is 3104944833. The repair is classified as both mobile-friendly and remote software upgrade (RSU) friendly.

Symptoms of a Faulty Electric Auxiliary Heater

The primary symptom of this issue is the failure of the electric auxiliary heater. This component is crucial for providing heat to the vehicle's interior. Owners may notice a lack of cabin heating, especially in colder conditions, if the electric auxiliary heater is not functioning correctly.

Important Warnings for Owners and Technicians

BMW has issued several critical warnings regarding this service action, particularly concerning the high-voltage (HV) systems:

• "DO NOT OVERFILL THE COOLANT SYSTEM." This is a direct instruction for technicians during the repair process.
• High-Voltage System Safety: "Only properly trained personnel, who passed all applicable HV Technical Training Courses, should perform repairs which require disconnecting, or removal of High Voltage battery components on any Hybrid or Electric Vehicle. Work performed on High Voltage systems by unqualified persons may result in severe injury or damage to the vehicle." Additional safety information can be found in Repair Instruction 61 00, titled “Observe safety instructions when handling electric vehicles”.
• Technician Certification: Specific training is required for working on high-voltage systems. For Generation 4 vehicles, once the HV system is disabled (indicated by the "Blitz" - lightning bolt icon in the instrument cluster), a non-HV certified technician may remove certain HV components, but not the High Voltage Battery. For Generation 5 vehicles, specific training (e.g., ST2324, ST2205, ST2006, ST1825, ST2325) is mandatory for diagnosing, removing, and servicing any HV component.

Repair Procedure Summary

The correction for a faulty electric auxiliary heater involves its replacement. Technicians are instructed to follow Repair Instruction 64 12 821, which details the steps for "Replacing the electric auxiliary heater." After the replacement and refilling with new coolant, it is essential to bleed the cooling circuit. If any metal cooling system components were replaced, the cooling system's circuit must be drained and refilled with new coolant to ensure anti-corrosion protection.

Required Tools or Parts

The following parts are required for this service action:

• Part Number: 64 12 5B683B8
  • Description: Electric instantaneous water heater
  • Quantity: 1
• Part Number: 83 19 5A32851
  • Description: HT-12 Antifreeze RTU (Bulk DN = 1/10 Liter) (Pre-mix)
  • Quantity: As required
• Part Number: 83 19 2468442
  • Description: BMW Antifreeze/Coolant (DN = 1 Gallon Concentrate) - HT-12
  • Quantity: As required

Additional materials and small parts, such as fluids, lubricants, screws, nuts, and seals, should be selected according to the ISTA repair instructions or Electronic Parts Catalog (ETK/AIR) based on the specific vehicle type.

Owner Action

If you own a 2022-2025 BMW i4, i5, or i7, and suspect an issue with your electric auxiliary heater, or if you receive notification about Service Action SIB 64 09 25, you should contact your authorized BMW dealer. The repair will be covered under warranty. BMW provides for Alternative Mobility Solution (AMS) expense reimbursement for owners, as outlined in SI B01 29 16. Dealers are instructed to perform this procedure on all affected vehicles before customer delivery or at the next service visit if the customer has already taken delivery.

---

Source: NHTSA ID: 11026956