TSB B120721 — BMW Service bulletin

B120721 is a service bulletin on file with NHTSA for the BMW X5, 2019–2021 model years, filed and re-filed as 2 documents. A TSB is factory repair guidance, not a recall — the repair is not automatically free.

What the bulletin says. Check Control message (CCM) indicates: (ID 213): Stop, exercising due care. Voltage supply The Service Engine Soon light is on with the following DME Fault Code: 21B209 - Starter alternator / belt for 48V system (OSA_RIEMEN_RISS): Belt betweenCombustion engine and starter…

NHTSA's own summary of the document, quoted from the public manufacturer-communications file.

2Documents filed
1Vehicle named
3Model years

Vehicles and model years B120721 names

VehicleModel years
BMW X5 2019, 2020, 2021

Every document filed under B120721

Manufacturers re-issue a bulletin as the repair changes, and file separate copies for technicians and for owners. All of them carry the same number.

Document IDFiledType
B120721 March 4, 2024 Service bulletin
B120721 November 9, 2023 Service bulletin

What B120721 covers

Engine — the component vocabulary NHTSA files this communication under.

← All BMW X5 TSB years TSB lookup by model

Questions buyers ask

What is TSB B120721?

B120721 is a service bulletin filed with NHTSA by BMW, covering the BMW X5 across the 2019–2021 model years. NHTSA's summary reads: Check Control message (CCM) indicates: (ID 213): Stop, exercising due care. Voltage supply The Service Engine Soon light is on with the following DME Fault Code: 21B209 - Starter alternator / belt for 48V system (OSA_RIEMEN_RISS): Belt betweenCombustion engine and starter…

Which vehicles does B120721 cover?

NHTSA's file names BMW X5 (2019–2021). A bulletin number can be re-issued against more vehicles later, so check the model-year list on this page against your own.

Is TSB B120721 a recall, and is the repair free?

No. B120721 is repair guidance the manufacturer sent its dealers, not a safety defect finding. You pay for the work unless the vehicle is still under warranty. Recall repairs, by contrast, are always free.

How do I get the full text of B120721?

Take the document ID to a dealer's service desk, or search NHTSA's manufacturer-communications records. This page carries every document ID filed under B120721, its date, and NHTSA's own summary from the public file.

Data updated 2026-08-20 from NHTSA's public records

Every number on this page is a count of records in the federal complaint, recall, and investigation files published by NHTSA's Office of Defects Investigation. This page lists only what NHTSA's manufacturer-communications file records under B120721. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.