# Service bulletin B640326

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 11032742
- Published by NHTSA: 2026\-05\-18
- Manufacturer's number: B640326
- Manufacturer's date: 2026\-05\-07
- NHTSA component: ENGINE

## NHTSA's summary

After starting up the vehicle, a distinct, constant, “humming” noise can be heard from the right area of the instrument panel.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2026/MC-11032742-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2026/MC-11032742-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Engine

## Vehicles listed

- 2025 BMW IX

## Other bulletins for the same vehicles and component

- [B170124](/bulletins/11029046.md), 2026-02-26, Service bulletin: ENGINE. There is coolant leaking from under the car Low heater output Possible Check Control message “Drive, you can continue driving” \(ID49\) Possible fault codes stored in these BEV vehicles: 224163 – Electric auxiliary heater for the high\-voltage battery unit: Undervoltage or internal communication fault 8049AA \- Coolant level sensor, expansion tank: Coolant level low or short circuit to ground or line disconnection 80124F – Electric auxiliary heater: Communication in electric auxiliary heater faulty 224F60 \- Coolant level sensor, expansion tank: Coolant level low or short circuit to ground or line disconnection 224111 \- Cooling system for power electronics: Coolant loss detected 224107 \- Cooling system for high\-voltage battery unit, component protection: Detection of coolant loss
- [B170124](/bulletins/11016419.md), 2025-04-03, Service bulletin: ENGINE. There is coolant leaking from under the car Low heater output Possible Check Control message “Drive, you can continue driving” \(ID49\) Possible fault codes stored in these BEV vehicles: 224163 – Electric auxiliary heater for the high\-voltage battery unit: Undervoltage or internal communication fault 8049AA \- Coolant level sensor, expansion tank: Coolant level low or short circuit to ground or line disconnection 80124F – Electric auxiliary heater: Communication in electric auxiliary heater faulty 224F60 \- Coolant level sensor, expansion tank: Coolant level low or short circuit to ground or line disconnection 224111 \- Cooling system for power electronics: Coolant loss detected 224107 \- Cooling system for high\-voltage battery unit, component protection: Detection of coolant loss

JSON: [/v1/bulletins/11032742](/v1/bulletins/11032742)

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