# Service bulletin 2400621

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: 10223490
- Published by NHTSA: 2022\-10\-17
- Manufacturer's number: 2400621
- Manufacturer's date: 2021\-05\-12
- NHTSA component: ELECTRICAL SYSTEM:SOFTWARE; ELECTRICAL SYSTEM; VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM

## NHTSA's summary

Flash: Heating, Ventilation and Air Conditioning \(HVAC\) Module Updates This bulletin involves reprogramming the HVAC control module with the latest available software. The customer may experience a Malfunction Indicator Lamp \(MIL\) illumination with the following Diagnostic Trouble Code \(DTC\) or the symptom/conditions listed below: B10C8\-36 \- Cabin Fan Brushless \- Signal Frequency Too Low. The HVAC fan stops working after a Engine Start/Stop \(ESS\) function.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2021/MC-10223490-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2021/MC-10223490-9999.pdf)

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

## Components

Electrical system, Glass, wipers and mirrors, Heating and air conditioning, Software

## Trouble codes named

B10C8

## Vehicles listed

- 2021 ALFA ROMEO STELVIO

## Other bulletins for the same vehicles and component

- [0824323](/bulletins/10248929.md), 2024-01-16, Service bulletin: ELECTRICAL SYSTEM:SOFTWARE. USB Software Update to 131.010.002 for RAN Radio The customer may describe the following: ? Wrong temperature information is displayed on the performance page. This bulletin involves inspecting the software level to see if the radio needs one or two USB flash drive\(s\) to update the radio software level to 131.010.002. CAUTION\! The repair procedure must be followed step by step. If the radio is not updated with the correct software level at the correct time the radio can be damaged or the updates won?t complete.

JSON: [/v1/bulletins/10223490](/v1/bulletins/10223490)

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