Table 1 shows one common power train related problems of the 2023 BMW 740.
| Problem Category | Number of Problems |
|---|---|
| Power Train problems |
My 2023 BMW 740i has experienced the same serious failure twice at approximately 21,000 miles. The exact component causing the failure is currently unknown. The vehicle is available for inspection and is currently being returned to an authorized BMW dealer for diagnosis. During the first incident, while driving, multiple warnings suddenly appeared involving chassis stabilization, regenerative braking, the parking brake/roll-away system and drivetrain. The warnings escalated to “stop. Apply parking brake” and “drivetrain malfunction. You cannot continue driving. ” shortly afterward, the vehicle became completely immobilized and could not be shifted into drive, reverse or neutral. It had to be towed to an authorized BMW dealer. BMW diagnosed the first incident as a failed 12v battery and replaced the battery under warranty. Only days after receiving the vehicle back with the new battery, the same failure occurred again while I was driving. Warning messages appeared stating “drive carefully. Chassis stabilization,” “regenerative braking,” and “vehicle may roll. Brake manually. ” the vehicle then displayed “stop. Apply parking brake. Drivetrain malfunction. You cannot continue driving. ” once the final warning appeared, I had approximately 30 seconds to get out of active traffic before the vehicle became completely immobilized. I was fortunate to reach a parking area. Once stopped, the vehicle again could not be shifted into drive, reverse or neutral and required another tow. My primary safety concern is the extremely short amount of time between the warning to stop driving and complete immobilization. If this occurred on an interstate, railroad crossing, busy intersection or another location without an immediate safe place to stop, the vehicle could become disabled in active traffic. The first BMW repair did not correct the condition. The vehicle is now undergoing diagnosis for the second occurrence.
Component/system that failed: the rear differential failed internally, causing the left rear axle to separate from the differential housing. BMW’s own service center confirmed there was no external damage or outside force involved. The defective parts are currently with BMW of manhattan and can be made available for inspection. Safety risk posed: this failure created a significant safety hazard, as drivetrain separation while in motion can lead to loss of vehicle control, wheel lock, or a collision — especially at highway speeds. Fortunately, no accident occurred, but the risk was high. Was the problem confirmed by a dealer? yes. BMW of manhattan confirmed the failure in service invoice #1201464. Their technician wrote: “found left rear axle is popped out of differential. No signs of damage or outside influence. Differential is internally faulty. ” the dealership replaced the rear differential and associated components under warranty. Was the vehicle inspected by others? the vehicle was only inspected and repaired by BMW of manhattan, an authorized dealership. No police or insurance inspection occurred. Warning signs before failure? yes. The vehicle was brought to the dealership on four separate occasions before the failure due •loud noises from the rear axle area, •causing the abnormal wear and tear of tires , and •erratic driving behavior. Each time, BMW’s service team stated the vehicle was “in healthy shape. ” additional context: despite this failure being documented as internal and not customer-induced, BMW north America has refused to accept responsibility or honor a buyback request. The vehicle is used for business purposes under cuatro sons inc. And has now been taken off the road due to the safety risk and unresolved concerns about reliability. We are seeking NHTSA’s investigation and intervention.