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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.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10230114
Published by NHTSA2023-01-17
Manufacturer's number2400621
Manufacturer's date2021-05-12
NHTSA componentEXTERIOR LIGHTING; ELECTRICAL SYSTEM; POWER TRAIN

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

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Electrical system, Lighting, Transmission and driveline

Trouble codes named

B10C8

Vehicles listed
ALFA ROMEO STELVIO2021

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
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S2621000003 REV.A2026-03-18. Service bulletin. The vehicle will exhibit a service transmission/check engine warning indicator for the following transmission models: 845RE, 8HP45, 850RE, 8HP50, 8HP70, 8HP75, 8HP75-PHEV, 8HP75-LCV, 8HP90, 8HP95. Transmissions may exhibit the following diagnostic codes: P07E4, P1DB2, P0716, P1B14, P0733, P1D90, P1DB7, P1B13.
S1408000384 REV.J2026-03-13. Service bulletin. Start Stop Charging Warning Lamp Illuminated On, Intelligent Battery Sensor (IBS) State of Charge (SOC) Inaccurate, Battery Charging Message, Presence of IBS related Diagnostic Trouble Codes (DTCs), or Battery Warning Lamp On
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1086872025-12-11. Service bulletin. Radio- Multi Media
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