BMW Recalls Sedans, Sports Cars, and SUVs for a Braking Defect

The software problem also affects the Toyota Supra coupe

2019 BMW Z4 grille Photo: BMW

BMW is recalling more than 50,000 cars and SUVs from the 2019 to 2021 model years to address a software problem that may cause the loss of braking assist, which can increase the risk of a crash.

BMW says that while braking assist may not work, all the affected vehicles retain mechanical braking capability, just without any boosted assistance. This problem affects BMW vehicles as well as the Toyota Supra, which is mechanically similar to the BMW Z4 roadster. 

If drivers find themselves without braking assist, they may have to press harder on the pedal to stop, and stopping distances may be longer.

According to the automaker, under certain starting conditions the engine management software could damage the oil/vacuum pump supplying the vacuum that enables the brake assist (also called brake boost) function. Either of these conditions has an impact on the system:

  • Pressing the engine start/stop button two times in rapid succession.
  • Depressing the brake pedal very briefly while pressing the engine start/stop button.

BMW says that while both of these situations could ultimately result in a loss of brake assist, the full brake assist function will remain available for about two or three full brake applications, or about six partial brake applications.

This problem became apparent after an increase in warranty claims early this year. BMW conducted an internal engineering review of the claims between February and April. A BMW spokesperson told CR in an email that the automaker is not aware of any crashes attributed to this issue.

The Details

Vehicles recalled: About 50,024 BMW and Toyota models.

  • 2020 BMW 540i, 540i xDrive (5,375 vehicles)
  • 2020-2021 BMW 745Le xDrive (470 vehicles)
  • 2020 BMW M340i, M340i xDrive (10,877 vehicles)
  • 2020 BMW X3 M40i (14,006 vehicles)
  • 2020-2021 BMW X4 M40i (4,130 vehicles)
  • 2019-2021 BMW Z4 M40i (2,151 vehicles)
  • 2020-2021 Toyota Supra (13,014 vehicles)

The problem: During engine start, a software problem may result in the vehicles losing the braking assist function.

The fix: BMW dealers will update the engine management software free of charge for all BMW models. Toyota dealers will update the software at no cost to Supra owners.

How to contact the manufacturer: BMW will notify owners by mail, with letters expected to be sent Oct. 1, 2021. Owners may contact BMW customer service at 800-525-7417. Supra owners may contact Toyota customer service at 800-331-4331.

NHTSA campaign number: 21V598. The BMW service information number is B12 06 21.

To see if your vehicle has an open recall that needs to be addressed, go to the National Highway Traffic Safety Administration website.

If you plug your car’s 17-digit vehicle identification number (VIN) into the website and a recall doesn’t appear, it means your vehicle doesn’t currently have one. Because automakers issue recalls often, and for many older vehicles, we recommend checking back regularly.

Stay informed about recalls that might affect your vehicle by using our Car Recall Tracker. Create a free account now to become a CR member. 


Jon Linkov

I owe my career to two fateful events: my father buying a 1965 Corvette and my purchase of an Audi A4 rather than a Chevy Tahoe. The Corvette jump-started my love of cars, and the Audi led me to automotive journalism, track days, and amateur car repair. In my free time I cycle as much as possible, no matter the season.