# Service bulletin 2400421

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: 10223488
- Published by NHTSA: 2022\-10\-17
- Manufacturer's number: 2400421
- Manufacturer's date: 2021\-05\-12
- NHTSA component: ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE \(ECU/ECM\):SOFTWARE; EXTERIOR LIGHTING; ELECTRICAL 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-10223488-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2021/MC-10223488-9999.pdf)

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

## Components

Electrical system, Engine, Lighting, Engine control module

## Trouble codes named

B10C8

## Vehicles listed

- 2020 ALFA ROMEO STELVIO

## Other bulletins for the same vehicles and component

- [S2208000073](/bulletins/10229059.md), 2023-01-09, Service bulletin: ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE \(ECU/ECM\). No Start, After Flash And Or PCM Replace, DTC P0513 Invalid Skim Key Setting

JSON: [/v1/bulletins/10223488](/v1/bulletins/10223488)

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