2024 Toyota BZ4X electrical problems

Filed Nov 9, 2026 · Electrical · NJ

The 12-volt auxiliary battery in my 2024 Toyota bZ4X repeatedly drains and fails, leaving the vehicle completely unable to start. This has happened multiple times since XXX, including State Farm Emergency Road Service events on XX, requiring jump starts and tows. The first occurrence was at about 8,000 miles. The vehicle becomes inoperable without warning and cannot be restarted, which is a safety concern because it can leave the driver stranded without warning. The selling dealer, Team Toyota of Princeton in [XXX], has been unable to diagnose or repair the problem despite repeated reports and visits in XXX, and Toyota closed one corporate case without a fix. The problem has not been reproduced or confirmed by the dealer. The vehicle is available for inspection upon request. No crash, fire, or injury occurred. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 22, 2026 · Brakes, Electrical · FL · crash

The vehicle experienced a sudden, catastrophic brake-by-wire system failure while operating in one-pedal driving (Regeneration Boost mode). While decelerating at a low speed behind an 18-wheeler semi-truck, the vehicle failed to continue slowing down. I immediately depressed the physical brake pedal, but the vehicle completely ignored the foot pressure. The pedal and braking system became completely unresponsive, and the vehicle kept rolling forward uncommanded. Despite keeping the brake pedal fully depressed, the vehicle did not decelerate, resulting in a front-end low-speed collision with the metal rear bumper of the semi-truck. Because the collision occurred at a very low speed, the operator of the commercial truck was unaware of the impact and safely continued driving forward without stopping. The vehicle's brakes entirely refused to re-engage until I frantically pumped the physical brake pedal and cycled/pressed vehicle control power switches. This action seemingly forced the electronic braking modules to reboot or re-establish hydraulic pressure, allowing the vehicle to finally come to a stop. The vehicle was subsequently removed from the active roadway. This is a severe, life-threatening safety defect involving a total loss of electronic brake-by-wire and friction braking application without any mechanical override intervention, presenting an extreme hazard. The vehicle has been towed directly to an authorized Toyota dealership for a comprehensive electronic diagnostic pre-scan of the Skid Control ECU, Electronic Parking Brake system, and 12-volt auxiliary power systems to retrieve the stored DTC fault logs and freeze-frame data.

Filed May 5, 2026 · Electrical, Transmission · 9,787 miles · RI

The contact owns a 2024 Toyota BZ4X. When pressing the accelerator toelerator pedal to go onto the freeway, the vehicle failed to accelerate and suddenly shifted to neutral. The contact would have to press the brake pedal, the contact would immediately shift the vehicle back to Drive and continue forward. While continuing to drive, the vehicle accelerated. There were no warning lights. The failure had occurred 3 times. When attempting to start the vehicle one day, the vehicle failed to start. The tow company came and provided a jump-start, and then advised the contact to drive carefully, but if it failed to go in reverse. The next morning, the tow company's mechanic came again and confirmed battery failure, then recommended the vehicle be taken to the dealer. The vehicle was towed to the dealer, who stated that the battery had not failed, but had not provided a diagnosis for the failure. The vehicle had not been repaired. The dealer had driven the vehicle back to the contact's home. After the vehicle was returned, the failure occurred again. The manufacturer was informed, and a claim had been filed. The failure mileage was 9,787.

Filed Nov 17, 2025 · Driver assistance, Electrical · CA

I leased a toyota bz4x the parking brake lights and other lights come on and off while I am driving and fob is not touched. I took car in to be service for regular maintenance and was told I had to pay $295 and I am under warranty. I was sold the car brand new and I don't think it is. I keep hearing people talking when the car is powered off. I reported this several times and was ignored. My car keeps trying to cut off while I am driving and the car starts shaking, all the lights come on then go off. I was told I could get my car service anywhere for no charge under warranty. I was turned away. Its n been a year and no service car has not been serviced at all. I took it 2 times for service and the car has not been service. It is supposed to be new.

Filed Oct 24, 2025 · Brakes, Electrical · CA

The vehicle experienced repeated electrical and brake system malfunctions that pose serious safety concerns. On multiple occasions, the brake pedal became stiff and unresponsive while driving, and the parking brake system failed to engage properly. In addition, the ignition system often failed to start, even when the battery and all power indicators appeared normal. At times, the vehicle’s electrical system completely shut down without warning — causing loss of power functions, dashboard lights, and essential safety controls. These failures occur intermittently and unpredictably, making the vehicle unreliable and unsafe to operate. The issue has been reported to the dealer for inspection, but the problem continues to occur. It appears to be related to the vehicle’s electronic brake control and ignition system. This malfunction places the driver and others at potential risk, especially if the brake system or electrical components fail while the vehicle is in motion.

Filed Oct 8, 2025 · Driver assistance, Electrical · LA

I am writing to formally report ongoing issues with my Toyota bZ4X that raise serious safety concerns. The vehicle has been inspected twice by authorized Toyota service centers, and each time I have been told that no problems were found. However, the following issues continue to persist:     1.    Inaccurate Battery Readings: The electric system appears to malfunction regularly. The displayed battery percentage and estimated mileage are inconsistent and unreliable. For example, the battery may indicate a higher percentage while simultaneously showing a drastically reduced range, or vice versa.     2.    Lane Departure Warning Malfunction: The lane departure system activates erratically, sometimes without any lane deviation. At other times, it fails to engage when it should, which compromises the vehicle’s safety features.     3.    Tire Pressure Monitoring System (TPMS) Alerts: Warning lights frequently come on indicating that the tires are losing pressure, even after verifying that tire pressures are within recommended levels. These warnings occur unpredictably and without cause. Despite having the vehicle inspected twice, I have not received a resolution or acknowledgment of any defects. Toyota has stated that nothing is wrong with the vehicle, but the issues are ongoing and continue to impact the car’s drivability and safety. These problems are not only frustrating but also present a potential risk while driving. I am requesting that Toyota take this matter seriously, investigate the root cause of these electrical system malfunctions, and provide a resolution that ensures the vehicle operates safely and reliably.

Filed Aug 22, 2025 · Electrical · CA

The 12 volt battery does not maintain a charge. I have had it replaced twice. I purchased new January 2025; first battery replaced on March 20, 2025; second battery replaced August 13, 2025. I am currently having the same issue with the battery management system which controls temperature and battery usage. After sitting overnight, I drove my car approximately three miles parked and attempted to use the key fob to secure the vehicle, it failed. I had no problem or indication at the start of my trip. I had to secure the door with my physical key. I returned to the vehicle 15 minutes later and the key fob would not work at all. I accessed the vehicle with the physical key. The alarm was activated upon entry. I tried to use my key fob to get the vehicle to deactivate the alarm system but it would not work. Approximately five minutes later and after several attempts, the alarm stopped and the vehicle was showing ‘Ready’ but ‘No Key Detected’ was flashing on the information screen and vehicle would not change mode from park to reverse or drive. After several attempts of holding the key fob directly over the ‘START/STOP’ button, the car showed ‘ READY’ and I was able to change modes. The vehicle started flashing ‘NO KEY DETECTED’ continuously while I quickly drove back home. I parked in my driveway and made an appointment with Toyota for service. Later in the day, I attempted my key fob again, to no avail. I was able to get the key detected, display showed ‘Ready’ and mode changed. My car does not start (READY) until after several attempts. The dealership advised the battery failed a load test overnight and was replaced (August 15th) After the second replacement my car sat overnight. I drove a few miles to a charging station. I placed the car in ‘My Room Mode’ to have access to the climate control system and radio. The car started flashing ‘low voltage/battery’, I turned off the accessory mode, returned to the dealer, and awaiting resolution. Case filed with NCDS/CDSP.

Filed Apr 12, 2025 · Electrical · CO

The air conditioner/heat pump has went out twice in 5 months. AC compressor failure poses several safety risks, including the potential for fires, refrigerant leaks leading to health hazards, and increased humidity fostering mold and mildew growth, which can worsen indoor air quality and lead to respiratory issues. Causing concern of leaking refrigerant into the cabin of the vehicle could lead to cancer and death.

Filed Mar 26, 2025 · Brakes, Electrical · AZ

2024 BZ4x, 590 miles on ODO. Purchased the car on Sunday, 03/23/2025. Monday Morning - Turning on the Car (In my garage). I had it in "ready" while I tried to connect my Toyota app to the car, While talking to Toyota engagement for help.. (Never was able to change the primary driver on it.) The accessory lights flickered and a bell went on and off. Then the car went totally black. Toyota called a tow truck driver. He jumped the 12 volt. It gave it enough juice so I put in reverse and there was a Loud Grinding noise. "Brake System Malfunction- Take to Dealer." Tow truck loaded it up, grinding and all, took it to Toyota. There, found out the 12 volt battery died. No reported grinding when off loading or at the dealer. Toyota Dealer replaced the 12 volt battery on Monday 03/24/2025. Picked it up, drove it around about 40 miles and parked it in my garage. Parked with >80% battery on Lith battery Monday night 21:00. Sat in the Garage on Tuesday. Wednesday Morning 08:00am, 12 Volt COMPLETLY DEAD. It's back at the dealership. MY safety concern - Does this mean the Brake system will "malfunction" if the 12 volt battery isn't holding enough charge to operate the BRAKE SYSTEM?! Not sure if it means the parking brake or the actual brakes.

Filed Feb 13, 2025 · Electrical · 12,389 miles · GA

The contact owns a 2024 Toyota BZ4X. The contact stated that the battery failed to retain a charge, resulting in the doors not unlocking as needed. The contact stated that the dealer had previously replaced the battery, but the failure persisted. The vehicle was towed back to the dealer, who determined that the battery had failed again. The vehicle was not repaired and remained at the dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 12,389.