2020 BMW 3 Series Problems: 53 Known Issues

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the wiring for the Hall effect sensor in the driver and/or front passenger seat-belt buckle may not have been made to the specified length. Excessive bending of the buckle could start to separate the sensor, which could then read a belted occupant as unbelted and lead to an inappropriate air bag and pre-tensioner strategy in a crash, increasing the risk of injury. The belt warning sounds and shows while the belt is buckled. Applies to: 2020 BMW 330i, 330i xDrive and M340i built January 28 to February 6, 2020 (Part 573, about 1,138 cars). BMW's dealer bulletin lists G20 3 Series Sedans built January 28 to February 18, 2020. A BMW dealer confirms by VIN.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a restraint-system Check Control message appears and the red airbag warning light stays on, with knee-airbag short-circuit or resistance faults stored, because the knee-airbag wiring harness may rub against the instrument panel support tube. Applies to: G20 3 Series Sedans from start of production to October 26, 2021 (all US cars have knee airbags), per bulletin 65 20 22.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), on the foldable rear center head restraint, the interlock may not have been welded sufficiently to the support-rod bracket at the supplier. Under load, such as in a rear impact, the weld could break and the headrest could fold down, increasing the risk of injury to a rear center passenger. Applies to: Two 2020 BMW M340i / M340i xDrive sedans built July 4 to July 31, 2019. Only a BMW dealer or nhtsa.gov/recalls can say whether a given VIN is one of them.

On the 2020 BMW 3 Series B58B30 3.0L turbo inline-six (B58D in BMW bulletins), if the engine starter is mechanically damaged, the engine may not start, and repeated or very long starting attempts can electrically overload and locally overheat the starter. If nearby engine acoustic insulation is contaminated (for example by oil), BMW says this could in rare cases lead to a thermal event while driving or shortly after parking. Applies to: 2020 BMW M340i and M340i xDrive (G20 3 Series Sedan, B58D). Recall 24V-576 lists them built September 12, 2018 to May 29, 2020; recall 25V-644 lists the 2020 "340I" built February 21, 2019 to July 28, 2020 and includes cars already repaired under 24V-576. A BMW dealer or nhtsa.gov/recalls confirms by VIN.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a software error in the 12-volt dual storage system (DSS) lithium-ion battery can intermittently make its microcontroller keep resetting and lose communication, which shows a red Check Control message (battery faulty / replace battery). Applies to: G20 3 Series Sedans built August 2018 to March 2019 (service action 61 03 19) or December 4, 2019 to December 2, 2020 (service action 61 03 21). 2020 M340i production ran February 21, 2019 to July 28, 2020 (Part 573 25V-644, Vehicle 6), so the VIN decides.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), in a crash the two-battery dual storage system is meant to disconnect from the electrical system through an internal relay. In some cases the relay sticks closed and a fault is set; the crash shutdown then does not happen and the power distribution box stays powered until the DSS is fully discharged. Applies to: G20 3 Series Sedans built June 15, 2018 to August 8, 2019 (service action 61 13 19) or April 10 to August 20, 2019 (service action 61 13 20). 2020 M340i production ran February 21, 2019 to July 28, 2020 (Part 573 25V-644, Vehicle 6), so the VIN decides.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), because of its confined mounting position, component tolerances and nearby sharp-edged parts, the engine wiring harness by the dual storage battery compartment may be damaged even when routed correctly. Depending on the damage, this can cause many electrical faults and warning lights in the instrument cluster or central display. Applies to: G20 3 Series Sedans built October 24, 2018 to March 19, 2019, per service action 61 21 19. Only early 2020 M340i builds can fall in this window (2020 M340i production ran February 21, 2019 to July 28, 2020 (Part 573 25V-644, Vehicle 6), so the VIN decides.)

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the anti-theft alarm can trigger for no apparent reason with all doors and windows closed, because of the sensitivity of the interior ultrasound sensor in the roof function center. Applies to: G20 3 Series Sedans with the alarm system (option 302), per bulletin 65 02 21.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the instrument cluster can display "Brake fluid service due since 12/2001" although the car is no more than a year old, because of an instrument cluster software error. Applies to: G20 3 Series Sedans with Live Cockpit Professional (option 6U3) built from March 2019, per bulletin 62 10 19.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the car may not open, close or start with Comfort Access, and may not start even with the key held against the steering column. BMW gives three causes: a Body Domain Controller (BDC) software error (66 24 19); the key fob dropping into deep sleep after an electrostatic discharge (66 19 19); and, with Comfort Access, a temporary BDC communication interruption above about 60°F that clears once the car sleeps or cools (61 04 20). Applies to: G20 3 Series Sedans from start of production (66 24 19); G20 built up to January 1, 2020 (66 19 19); G20 with Comfort Access (option 322) from start of production (61 04 20).

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), check Control message 128 "High beam headlight failure" can appear, with short-circuit fault codes stored, although all lights work correctly. BMW traces it to a Body Domain Controller software error. Applies to: G20 3 Series Sedans and other listed models below software level S18A-21-07-555, per bulletin 63 08 21 rev. 1.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), accessories plugged into the front 12-volt socket may not power up, or only work with constant downward pressure, because a design change meant to reduce short circuits can stop the adapter's center pin making proper contact. Applies to: G20 3 Series Sedans without the heated cupholder (option 44A), per bulletin 61 01 20 rev. 7.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), with BMW Live Cockpit Professional, the instrument cluster can stay dark after starting until a restart (62 09 19), or cluster functions can intermittently stop working, including the on-board computer button, radio and turn-signal displays and steering-wheel controls (62 01 19). BMW traces both to instrument cluster software. Applies to: G20 3 Series Sedans with Live Cockpit Professional (option 6U3), all production, per bulletins 62 09 19 and 62 01 19 rev. 4; 62 01 19 names software level S18A-18-11-5xx.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), during a parking maneuver or when using the parking assistant, various Check Control messages such as "Park Assist failed" or lateral parking aid failure can appear. BMW traces it to insufficient steering-angle adjustment during production, only on cars with a JTEKT electric power steering gear. Applies to: G20 3 Series Sedans built up to May 28, 2020 with Park Distance Control (508) or Parking Assistant Plus (5DN) and a JTEKT steering gear (G20 can have JTEKT or ThyssenKrupp Presta), per bulletin 66 16 20 rev. 1.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the left or right rear short-range radar (SRR) sensor may have reduced function because of its hardware, which displays the Driving Assistance Check Control message. Applies to: G20 3 Series Sedans with Driving Assistant (5AS) or Driving Assistant Professional (5AU) built December 3, 2019 to January 31, 2020, per service actions 66 07 20 (left) and 66 08 20 (right). Not every car needs both sides.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the top (surround) view image can be misaligned, so parking-space lines shown in the central display are not parallel to the side of the car. BMW traces it to the side-view camera fitting loosely in the exterior mirror bracket. Applies to: G20 3 Series Sedans with Parking Assistant Plus (5DN), per bulletin 66 29 19 rev. 4.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the Bowden cable for the manual trunk release inside the trunk may not have been installed to specification. The release might then not unlatch the trunk lid from inside, so a person trapped in the trunk may not be able to get out; the cars may not meet federal standard FMVSS 401. Applies to: 2020 BMW 330i, 330i xDrive and M340i built July 31 to September 18, 2019 (about 325 cars). A BMW dealer confirms by VIN.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the rear window (back glass) may not have been properly bonded to the body during production. This applies to G20 3 Series Sedans built July 13 to September 1, 2020, per service action 51 26 20. The bulletin is scoped by build date, not model year, so the VIN decides whether a given 2020 M340i is included.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the sunroof frame may not have been properly sealed during production, causing a water leak into the vehicle. This applies to 28 G20 3 Series Sedans built November 2018 to September 2019, per service action 54 01 20. Only a BMW dealer can say by VIN whether a given 2020 M340i is one of them.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a ticking noise can come from the A-pillar and side mirror area at about 40 mph, on either side, caused by the mirror wiring harness touching the mirror cap. Applies to: G20 3 Series Sedans built up to September 30, 2020, per bulletin 51 03 21.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a rattle can come from the cowl area under the windshield while driving at temperatures below 50°F, on one or both sides, because the cowl panels can touch the adjacent panels in the cold. Applies to: G20 3 Series Sedans, per bulletin 51 02 20; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), one or more doors may need increased effort to open: the door seems stuck when using the outer handle, or the inner handle must be pulled to its limit. BMW lists improper door striker adjustment or a faulty door latch as causes. Applies to: G20 3 Series Sedans, per bulletin 51 07 21; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a whistling noise can come from the front bumper at highway speeds, caused by the bottom clips of the lower grille. Applies to: G20 3 Series Sedans, per bulletin 51 08 22; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a whistling noise can come from one or both front doors at about 60 mph because foam acoustic seals at the A-pillar and B-pillar may have shrunk or shifted, letting air leak. Applies to: G20 3 Series Sedans, per bulletin 51 25 20; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), relative movement between the front side panel (fender) and the wheel-arch liner while driving can, over time, abrade and damage the painted surface of the fender. Applies to: G20 3 Series Sedans built February 7, 2018 to November 17, 2020, per service action 41 03 21.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), in rare cases, if the car is locked with the remote key while the fuel filler door is being pushed closed, the fuel door can enter a locked state that cannot be unlocked. Applies to: G20 3 Series Sedans and other listed models, per bulletin 51 27 20; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), after the hood release lever is pulled twice, the hood only reaches the pre-latch position on both sides because the hood latch mechanical release is not operating properly. Applies to: G20 3 Series Sedans, per bulletin 51 22 22; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), creaking, groaning or clicking noises can occur when folding the side mirrors in or out, caused by excessive friction on the mirror hinge pivot. Applies to: G20 3 Series Sedans, per bulletin 51 10 20; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the sunroof reverses direction (anti-trap) just as the glass meets the wind deflector and may not initialize properly. For the G20, BMW traces it to a software error in the roof function center (FZD). Applies to: G20 3 Series Sedans built up to March 31, 2020, per bulletin 54 08 19 rev. 5.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the sunroof roller sunblind may not open from fully closed, or may not close with the one-touch function, because of lost initialization or a Hall sensor fault in the sunblind drive. Applies to: G20 3 Series Sedans, per bulletin 54 02 20; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), rattling can be heard near the glove box on rough roads because the washer fluid reservoir's upper plastic locating tab has too much side play in its metal bracket. Applies to: G20 3 Series Sedans and other listed models, per bulletin 61 06 15 rev. 4; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), with Active Cruise Control with Stop & Go on, the car can slow down unexpectedly when the rear side radar sensors falsely detect an object from signal echoes, for example with a bicycle carrier loaded with several bikes, or on narrow roads with guard rails or slow traffic. BMW traces it to optional-equipment system (SAS) software. This applies to G20 3 Series Sedans from start of production with Driving Assistant Professional (5AU) and a factory or retrofitted trailer hitch (3AC), per bulletin 66 15 20.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), there may be no bass, or a cracking noise, from the bass speakers because of a fault in the Top HiFi system amplifier. Applies to: G20 3 Series Sedans built March 1 to November 23, 2020 with the Harman Kardon system (option 688) and Live Cockpit Plus or Professional (6U2 or 6U3), per bulletin 65 01 21. 2020 M340i production ran February 21, 2019 to July 28, 2020 (Part 573 25V-644, Vehicle 6), so the VIN decides.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), with the Live Cockpit head unit, the radio or music can cut out, navigation can stop and the central screen can go black before the system restarts (65 09 19, and 65 15 20 when using 3D buildings in navigation), or all sound including phone and voice output can drop out intermittently (65 09 22). BMW traces each to head unit software. Applies to: G20 3 Series Sedans with Live Cockpit Professional (6U3) for 65 09 19 and 65 15 20, and with Live Cockpit Plus or Professional plus the satellite tuner (655) for 65 09 22, at the software levels the bulletins list.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the yellow Check Control message ID 42 ("Brake system") can appear at start-up. Depending on timing, the parking brake may not work or release, or ABS and other stability functions may be unavailable; fault 48082F is stored. BMW traces it to unfavorable software in the DSC unit; the message goes out after another ignition cycle. Applies to: G20 3 Series Sedans built November 5, 2018 to July 1, 2021, per bulletin 34 08 21.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the service display and Check Control message show worn rear brake pads before 15,500 miles. BMW traces it to increased residual braking force in the rear calipers caused by production deviations on the piston ring seal surface. This applies to G20 3 Series Sedans built November 1, 2018 to December 31, 2019 with what BMW calls standard brakes, per bulletin 34 03 20, which lists replacement rear caliper housings for the M340i and M340i xDrive. A BMW dealer confirms by VIN and equipment.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a ticking noise comes from a front wheel while cornering at low speed without the brakes applied. BMW traces it to microscopic movement at the contact surface between the lightweight brake disc and the wheel bearing flange. Applies to: Listed models with 5x112 wheel bolts including the G20 3 Series Sedan, on cars with lightweight front brake discs, per bulletin 34 05 17 rev. 4; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a rattling noise can be heard in the cabin with the air conditioning on, because the refrigerant double pipe and a clamp on the internal heat exchanger return line touch each other on the driver's side of the engine bay. Applies to: G20 3 Series Sedans from start of production, per bulletin 64 05 21 rev. 1.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a groaning noise can come from the heating and air-conditioning unit in the center of the dash whenever a ventilation, stratification or recirculation flap moves. BMW lists contamination reducing lubrication of the flap kinematics, or incorrect tolerances, as causes. Applies to: G20 3 Series Sedans and other listed models, per bulletin 64 04 22; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the inside of the windshield can mist over when driving off or after an automatic engine start-stop, and the recirculation flap may be heard opening and closing repeatedly. BMW traces it to implausible readings from the automatic air recirculation (AUC) sensor. Applies to: G20 3 Series Sedans and other listed models fitted with AUC sensor part number 64 11 5 A3F 255 or 64 11 5 A3F 250, per bulletin 64 02 22.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a rattle can come from the dashboard center speaker cover, sometimes only during phone calls or at certain music volumes or tones, because the cover contacts the dashboard. Applies to: G20 3 Series Sedans, per bulletin 51 14 20; no production dates given.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), when the car is pre-heated with Remote Engine Start, the driver's seat heating does not switch on even with automatic seat heating active, because of a seat-module coding error from programming at certain software levels. Applies to: G20 3 Series Sedans built November 1, 2018 to November 1, 2019 with both Remote Engine Start (option 1CR) and memory seats (option 459), per bulletin 52 07 20.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), on rough roads or cobblestones a whirring or squeaking noise can come from the steering-wheel airbag assembly, caused by a production label on the airbag harness vibrating. Applies to: G20 3 Series Sedans with the M Sport steering wheel (option 710) built from November 1, 2018, per bulletin 65 05 21.

On the 2020 BMW 3 Series B58B30 3.0L turbo inline-six (B58D in BMW bulletins), bMW says a software error may cause an unwanted pressure pulsation in the automatic transmission during a Remote Engine Start, and in rare circumstances this pulsation may damage the transmission. Applies to: G20 3 Series Sedans with the B58D engine built July 1, 2020 to June 30, 2022, per service action 24 03 23. Only the last 2020 M340i builds (July 1-28, 2020; 2020 M340i production ran February 21, 2019 to July 28, 2020 per Part 573 25V-644, Vehicle 6) can fall in this window, so the VIN decides.

On the 2020 BMW 3 Series B58B30 3.0L turbo inline-six (B58D in BMW bulletins), a cracking, metallic noise can come from under the center of the car when going from off-throttle to on-throttle or back, or when shifting between Drive and Reverse while stationary. BMW traces it to unfavorable tolerances of the automatic transmission output flange. Applies to: Rear-wheel-drive G20 3 Series Sedans with the 8HP51 automatic transmission (no xDrive models), per bulletin 24 02 22. The bulletin gives no production dates or trims, so a BMW dealer must confirm the transmission fitted.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), if power to the steering gear is lost while the steering is turned more than 15 degrees, a fault can occur in the steering system, setting fault entries and Check Control messages across the vehicle network. BMW traces it to a fault in the steering gear "zero position" calibration during production. Applies to: G20 3 Series Sedans identified by VIN, per service action 32 06 20; the bulletin gives no production dates.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the steering intervention of Lane Departure Warning can be too strong, which can feel uncomfortable to the driver. BMW traces it to a software error in the camera-based driver assistance (KAFAS) control unit or the optional-equipment system unit. The intervention can be overridden at any time. Applies to: G20 3 Series Sedans with Active Guard (5AV), Active Guard Plus (5AQ), Driving Assistant (5AS) or Driving Assistant Professional (5AU), per bulletin 66 15 19 rev. 3.

On the 2020 BMW 3 Series B58B30 3.0L turbo inline-six (B58D in BMW bulletins), bMW says software in the DSC unit could reduce brake regeneration for the next 40 drive cycles, so the vehicle would not satisfy certain emissions requirements. Applies to: G20 3 Series Sedans with the B58D (or XB1G) engine built July 17, 2019 to October 21, 2020, per service action 34 06 21. 2020 M340i production ran February 21, 2019 to July 28, 2020 (Part 573 25V-644, Vehicle 6), so the VIN decides.

On the 2020 BMW 3 Series B58B30 3.0L turbo inline-six (B58D in BMW bulletins), the engine malfunction warning can come on with tank-ventilation or lean-mixture faults stored in the engine control unit. BMW traces it to an internal mechanical defect in the tank ventilation valve, which can also make a very loud clicking noise when the valve cycles. This applies to G20 3 Series Sedans with B58 engines (B58X in the bulletin) produced up to March 2019, per bulletin 13 04 20 rev. 01. The earliest 2020 M340i builds listed in NHTSA recall 25V-644 (Vehicle 6) date from February 21, 2019, so only the earliest 2020 builds can fall in this window; the build date decides.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), the corrosion protection applied inside the front axle support (subframe) at the factory may have minor coating defects, which in individual cases can lead to localized rust on the axle support over the life of the car. BMW calls it a manufacturing process error. Applies to: G20 3 Series Sedans (rear-wheel drive and xDrive) identified by VIN, per service action 31 07 19; the bulletin gives no production dates.

On the 2020 BMW 3 Series All (scoped by build date and equipment, not engine), a process fault at the supplier means the rubber mount in a front wishbone, or the hydraulic mount in a tension strut, may have been pressed in incorrectly, which can cause noises from the front axle. Applies to: G20 3 Series Sedans built June 19 to November 27, 2019, per service action 31 01 20; BMW selects the affected side by VIN.

On the 2020 BMW 3 Series B58B30 3.0L turbo inline-six (B58D in BMW bulletins), bMW says an unfavorable engine-computer (DME) diagnostic calibration may store fault 213A2B (increment wheel adaption faulty), which in most cases turns on the check-engine light. BMW says this is not associated with any drivability complaint. This applies to G20 3 Series Sedan with the B58D engine (and B46D) built with factory software level 19-07-500 or later, per bulletin 11 12 19. A BMW dealer can confirm the factory software level by VIN.

On the 2020 BMW 3 Series B58B30 3.0L turbo inline-six (B58D in BMW bulletins), after a cold start at 32°F (0°C) or below, a howling or whistling noise can come from under the car at 30-37 mph and go away as the driveline warms up. BMW traces it to unfavorable tolerances in the rear propeller-shaft center bearing. Applies to: G20 3 Series Sedans with the B46, B48 or B58 engine (and plug-in hybrids), per bulletin 26 04 22; no production dates given.