B0021
0 owner reports and 21 manufacturer filings across 9 model years from Cadillac, Chevrolet.
Where B0021 shows up
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports | Parts |
|---|---|---|---|---|
| 2023 Chevrolet Bolt EUV | Seats | 4 | — | |
| 2022 Chevrolet Bolt EUV | Air Bags | 4 | — | |
| 2023 Chevrolet Bolt EV | Seats | 4 | — | |
| 2022 Chevrolet Bolt EV | Electrical System | 4 | — | Battery → |
| 2023 Cadillac XT4 | Electrical System | 1 | — | Battery → |
| 2022 Cadillac XT4 | Seats | 1 | — | |
| 2021 Cadillac XT4 | Electrical System | 1 | — | Battery → |
| 2020 Cadillac XT4 | Electrical System | 1 | — | Battery → |
| 2019 Cadillac XT4 | Air Bags | 1 | — |
A model year appears here because the code is named in its record, not because every one of these vehicles sets it. Counts are mentions in the federal files, not failure rates — nobody publishes the denominator.
Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
B0021 by make
The same record, one make at a time: the model years, bulletins and owner reports that name B0021 on that maker’s vehicles.
What it gets filed under
21 manufacturer filings name B0021. Start with what the maker wrote down.
A code names the test that failed, not the part. A bulletin that names it is often a diagnosis someone has already written down — quote its number at the service desk.
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names B0021.
- 23-NA-110 Service bulletin2024-02-27 · Electrical System
- This technical bulletin provides a procedure to correct the condition of Intermittent Service Airbag System message (DTC B0014 B0021).
- 23-NA-030 Service bulletin2023-05-25 · Seats
- This service bulletin provides a procedure to replace the seat pad to correct the condition of Airbag Light On - DTCs B0014 / B0021 SIAB Harness Connector Contacting Seat Back Foam (New Seat Back Foam), Intermittent Service Airbag System Message, DTCs B0014, B0021.
- 23-NA-030 Service bulletin2023-04-14 · Air Bags
- This service bulletin provides a procedure to replace the seat pad to correct the condition of Airbag Light On - DTCs B0014 / B0021 SIAB Harness Connector Contacting Seat Back Foam (New Seat Back Foam), Intermittent Service Airbag System Message, DTCs B0014, B0021.
- 23-NA-030 Service bulletin2023-03-01 · Seats
- This service bulletin provides a procedure to replace the seat pad to correct the condition of Airbag Light On - DTCs B0014 / B0021 SIAB Harness Connector Contacting Seat Back Foam (New Seat Back Foam), Intermittent Service Airbag System Message, DTCs B0014, B0021.
What B0021 means
Source: SAE J2012 / OBD-IIB0021 sits in the generic range of the OBD-II standard, so it means the same thing on every vehicle sold in the United States — but WhichTrim does not carry a definition for it and will not invent one. What is on this page is the record: who named it and on what.
A stored code names the test that failed, never the part that caused it. It is the starting point of a diagnosis, not its conclusion — the same code has several possible causes and the cheap one is not always right.
Common questions about B0021
Source: NHTSA files and the OBD-II standardCan I keep driving with B0021 stored?
Nobody can answer that from the code alone, and a site that does is guessing. A steady light means a fault was logged and the car should be checked soon; a flashing light means a severe misfire — slow down and get it seen as soon as possible, because severe misfire can quickly damage the catalytic converter. The safe read of this page is the mileage and the components, not permission.
Does a code mean the car is recalled?
No. Recalls are filed by campaign and matched by VIN, and none of them are triggered by a scan tool. If you want to know whether an open recall applies to one specific vehicle, check the VIN at nhtsa.gov/recalls — that is the only source that settles it.
Why do the counts here differ from other sites?
Because these are not estimates. Every number on this page is a count of documents in NHTSA's own files: manufacturer communications that name the code in their filed summary, and owner complaints that name it in the narrative. We do not model, weight or extrapolate them.
Will clearing the code fix it?
Clearing turns the light off and erases the freeze-frame data a technician would have used to work out what happened. If the condition is still there the code returns, usually within a few drive cycles, and the diagnosis now starts from less information than before.