B1E21 on Alfa Romeo vehicles
B1E21 is named on 19 Alfa Romeo model years (2019–2026): 37 manufacturer filings and 0 owner reports in NHTSA’s files, across Giulia, Stelvio, Tonale.
Which Alfa Romeo model years name B1E21
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2026 Alfa Romeo Giulia | Electrical System | 2 | — |
| 2026 Alfa Romeo Stelvio | Electrical System | 2 | — |
| 2026 Alfa Romeo Tonale | Electrical System | 2 | — |
| 2025 Alfa Romeo Giulia | Electrical System | 2 | — |
| 2025 Alfa Romeo Stelvio | Electrical System | 2 | — |
| 2025 Alfa Romeo Tonale | Electrical System | 2 | — |
| 2024 Alfa Romeo Giulia | Electrical System | 2 | — |
| 2024 Alfa Romeo Stelvio | Electrical System | 2 | — |
| 2024 Alfa Romeo Tonale | Electrical System | 2 | — |
| 2023 Alfa Romeo Giulia | Electrical System | 2 | — |
| 2023 Alfa Romeo Stelvio | Electrical System | 2 | — |
| 2022 Alfa Romeo Giulia | Electrical System | 2 | — |
| 2021 Alfa Romeo Giulia | Electrical System | 2 | — |
| 2021 Alfa Romeo Stelvio | Electrical System | 2 | — |
| 2020 Alfa Romeo Giulia | Electrical System | 2 | — |
| 2020 Alfa Romeo Stelvio | Electrical System | 2 | — |
| 2019 Alfa Romeo Giulia | Electrical System | 2 | — |
| 2019 Alfa Romeo Stelvio | Electrical System | 2 | — |
| 2022 Alfa Romeo Stelvio | Electrical System | 1 | — |
A model year is listed because the code is named in its own record — a bulletin filed against it, or an owner’s complaint about it — not because every one of these vehicles sets it. Counts are documents in NHTSA’s files, not failure rates.
Alfa Romeo filings that name B1E21
Source: NHTSA manufacturer communicationsBulletins and campaigns Alfa Romeo filed with NHTSA whose summary names B1E21. Quote the document number at the service desk — it is a diagnosis the maker has already written down.
- 08-394-25 Service bulletin2025-12-05 · Electrical System
- Telematics Box Module (TBM) Backup Battery Replacement When DTC B1E21 Is Present echnicians may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may exhibit/set the following Diagnostic Trouble Code (DTC): ● B1E21-96 - Backup Battery Component Internal Failure
- 08-394-25 REV. A Service bulletin2025-12-12 · Electrical System
- Telematics Box Module (TBM) Backup Battery Replacement When DTC B1E21 Is Present Technicians may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may exhibit/set the following Diagnostic Trouble Code (DTC): ● B1E21-96 - Backup Battery Component Internal Failure.
What B1E21 means
Source: SAE J2012 / OBD-IIB1E21 is a manufacturer-specific code: the second character is a 1, which under the OBD-II standard hands the definition to whoever built the vehicle. The same code can mean one thing on a Ford and something unrelated on a Hyundai. Any site that prints a single definition for it is guessing.
A stored code names the test that failed, never the part that caused it. The record above is what Alfa Romeo and its owners have filed about it; the code’s page across every make has the whole file.
Common questions
Source: NHTSA files and the OBD-II standardIs B1E21 a known problem on Alfa Romeo vehicles?
It is a documented one: NHTSA's files hold 37 manufacturer filings and 0 owner reports naming B1E21 on 19 Alfa Romeo model years (2019–2026). Whether it is a problem on one particular car is a diagnosis, not a count — but a bulletin that names the code on your model year is the place to start.
Which Alfa Romeo models does B1E21 appear on most?
2026 Giulia (2 documents), 2025 Giulia (2 documents), 2024 Giulia (2 documents).
Does B1E21 on a Alfa Romeo mean it is recalled?
No. Recalls are filed by campaign and matched by VIN; no recall is triggered by a scan tool. Check the VIN at nhtsa.gov/recalls, or open the model year's page here for the campaigns filed against it.