2024 Mazda CX-90 Plug-In Hybrid Electrical Problems

Mileage when the problem started

Owner reports

Selected complaints filed with NHTSA by 2024 Mazda CX-90 Plug-In Hybrid owners, lightly cleaned up (personal details are redacted by NHTSA).

The contact owns a 2024 Mazda CX-90. The contact stated that on several occasions while driving at various speeds, the message "Vehicle Failure Detected - Hybrid System Malfunction", "Possibility of Restricted Power Output", "I-Activsense System Malfunction", "Dynamic Stability Control Malfunction", and "Push button Start System Malfunction" were displayed. Additionally, the I-Activsense warning light was illuminated. The vehicle was taken to a dealer where it was diagnosed that an unknown software needed to be updated. The vehicle was repaired but the failure reoccurred. The vehicle was taken back to the same dealer where it was diagnosed that the connector to the battery needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 3,960.

Driving up snowy pass on I-90 approaching the top of Snoqualmie Pass. Vehicle stalled and warning lights flashed critical warning and loss of power. The vehicle stopped in the middle of the highway and would not start or go into drive. After a few minutes, because of speeding and adverse conditions, another driver collided with my vehicle from behind. Another following vehicle lost control and ran off the road. Nobody was injured. Mazda has not provided any information to what happened with the vehicle. We added about 12k miles in the 5 months of driving it, so we had lots of testing with it, and never ran into this serious of an issue with this or any other vehicle.

At approximately 16:50 engine malfunction warning light appeared and dealership was notified. Appointment scheduled for 4 days after. At 17:21 car began swerving uncontrollably along I80 with warning "engine malfunction, have the vehicle inspected." The car was shaking violently and veered off the road into the ditch between the eastbound and westbound highway. The car was totaled. Review of the vehicle app indicated that just before the crash at 17:19 several critical vehicle malfunctions messages appeared. The vehicle crashed at 17:21.

The contact owns a 2024 Mazda CX-90. The contact stated while driving at approximately 3 MPH, the vehicle unintendedly accelerated; however, the accelerator pedal was not being depressed during the failure. No warning light was illuminated. The vehicle was taken to a dealer and was diagnosed that a software update was needed. The vehicle was repaired; however, the failure persisted. The manufacturer was notified of the failure. The failure mileage was approximately 3,000.

Vehicle was parked in garage overnight in our house. At approximately 630AM, carbon monoxide detector alarmed indicating high CO levels inside the house. Source likely appeared to the vehicle- distinct odor of burned electrical wiring/insulation; vehicle felt warm to the touch. Vehicle was dead and would not start. Mazda app indicated critical warnings for ACTIVESENSE, hydrid battery, hydrid system malfunction, high voltage battery depletion, and charging system malfunction starting abruptly at 0210 hours and terminating at 0340 hours. Vehicle had simply been parked in garage and was not plugged in or charging. Last use of vehicle~930PM the night prior. There have been no prior warnings or indications of problems , vehicle has~1k mileage. Vehicle was purchased 7/5/23 and event occurred 7/30/23. Vehicle was towed and is in dealership currently. Mazada USA has been notified by us. …

What component or system failed or malfunctioned, and is it available for inspection upon request? "Hybrid System Malfunction. Stop Vehicle in a Safe Location." Car completely inoperable. Had to tow to dealership as would not start or go out of park. Hybrid and High Voltage battery issues reported by multiple owners. This happened less than a month into owning the vehicle and with less than 1200 miles. How was your safety or the safety of others put at risk? Car deceleration on highway specific to this error reported by multiple owners. Has the problem been reproduced or confirmed by a dealer or independent service center? Uknown. Currently being serviced by dealer. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Currently being inspected by the Mazda dealership I leased the vehicle through. …

CX90 PHEV Premium Plus new purchase 12/2023. 1/24/2024: "Hybrid System Malfunction, Have the vehicle Inspected " On a busy freeway with big rigs and other cars during rush hour traffic (5:25pm), going about 70 MPH. Only 1700miles on car so far. 50-60 degrees Fahrenheit outside. 2mi left on charge, full tank of gas. Car completely unable to accelerate all of the sudden on busy highway once this light came on. Was able to pull off to shoulder, albeit challenging as unable to accelerate and navigate through fast cars in right 2 lanes. Was able to restart car, and go at limp speed but unable to get fast enough to merge back. Called tow truck. Car towed to Mazda dealership. Then unable to get off flatbed of the tow truck as would not go into reverse. Tow guy called me and the staff at Mazda called their Service Manager, had to reset that code. …

At 3200 miles the vehicle had a major powertrain malfunction causing the vehicle to throw multiple error codes - Hybrid System Malfunction; Charging System Malfunction; Electrical Leakage Detected. Was instructed to pull over to a safe area immediately. Was unclear how long car would continue to be drivable. Once car stopped it became completely immobile. Repeated restart attempts would not let vehicle start ICE engine or shift into gear. Had to be towed via dollies to nearest dealer for diagnosis and repair. Dealer found a failed PTC heater unit as source of problem and replaced it (Mazda part- KMV6-61-FHX). Vehicle is once again drivable, but the dealer has no idea what would cause the unit to fail and how to avoid future problems. Dealer has heard about this with many vehicles and repaired several similarly. …

While connected to a level 2 charger, overheating caused both the charger and charging port of the vehicle to melt together such that it was very difficult to disconnect, and both were then unusable - needing replacement. (photos attached) We feel that there should be some safeguard in the vehicle to prevent this situation as it is a fire hazard. There were no warning lights, sounds, nor signals from the vehicle to warn of the problem. We were present when this occurred, so we could disconnect before a potential fire may have occurred. When we called for service, we had to wait two weeks for an appointment, and then were told that the car was not safe to drive until repaired. This was not considered a warranty item even though the car had fewer than 2800 miles and only owned by us for fewer than 7 months. We were charged $5000 for the charging port and cable assembly and $800 labor. …

Ever since the lease of this vehicle on January 2025 we've had problems with the brake/rotors took it in twice for that. As of recent August 2025, we took it in for loss of power going up a hill, hybrid malfunctioning electrical system going out. Dealership gave it back saying everything was fine. We took it on August 29, 2025 to Colorado vehicle failed to perform loss of power going up the mountain almost got hit by a vehicle because I was in a fast lane with my family had to pull over with whatever power I had left in the engine (not the battery). I mean the vehicle just keeps failing to perform as it should as well on the way back. It had the same issues but as severe going to Colorado.Vehicle does not change gears going uphill. When we stopped in Vegas for fuel, fuel door did not open it & malfunctioned. …

Electrical complaints in other CX-90 Plug-In Hybrid years