Mazda CX-5 electrical problems

The contact owns a 2016 Mazda CX-5. The contact stated that while driving 60 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal. No warning light was illuminated. In addition, there was an abnormal rattling sound coming from the engine. The contact pulled over to the side of the road before the vehicle stalled. The vehicle failed to restart. The vehicle was towed to an independent mechanic who determined that the engine had failed due to a lack of maintenance. The contact stated that the vehicle was equipped with an automatic reminder regarding the oil change. The contact stated that the oil change reminder failed to illuminate to indicate that the oil level was extremely low. The check engine warning light also failed to illuminate. The vehicle remained at the dealer unrepaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 130,000.

..... ON AT LEAST 5 SEPERATE OCCASIONS OUR 2021 MAZDA CX5 SUV ACCELERATED TO A HIGH RATE OF SPEED (ON IT'S OWN). IT HAS DONE IT TO MY WIFE AND I BOTH. I CONTACTED TWO DIFFERENT MAZDA SERVICE CENTERS AND WAS ADVISED THEY HAVE NO KNOWLEDGE OF THIS AND THAT THERE ARE NO OPEN RECALLS OR TSB's AND AS INTERMITTENT AS IT IS IT WOULD BE ALMOST IMPOSSIBLE TO DUPLICATE. ON JULY 18TH THE CAR ACCELERATED (ON ITS OWN) AGAIN BUT THIS TIME IT DROVE MY WIFE INTO A TREE AT APROX. 35/40 MPH BREAKING HER RIBS. THE BODY SHOP INFORMED ME THIS MORNING THAT THE CAR IS A TOTAL LOSS. MAZDA NEEDS TO GET TO THE BOTTOM OF THIS AND RESOLVE THIS ISSUE ASAP. THIS TIME IT WAS A TREE, THE NEXT TIME IT MAY BE AT A CROSSWALK OR AT AN INTERSECTION. IT'S JUST A MATER OF TIME UNTIL SOMEONE IS KILLED OR AT THE VERY LEAST BADLY HURT. I DON'T KNOW HOW MAZDA CAN BE UNAWARE OF THIS PROBLEM, IT'S ALL OVER THE INTERNET. OUR BODY SHOP PULLED IT UP ON LINE AND WAS SHOCKED AT THE AMOUNT OF COMPLAINTS/ CONCERNS THAT EXISTED RELATED TO THIS PROBLEM. PLEASE INVESTIGATE THIS BECAUSE THE NEXT PERSON MAY NOT BE AS FORTUNATE. THANK YOU IN ADVANCE.

I own a 2020 Mazda CX-5 equipped with the Mazda Connect infotainment system. The touchscreen display malfunctions regularly by randomly selecting menu items, jumping between screens, zooming in and out, and activating functions without any input from me. These “phantom touch” events occur even when the vehicle is in Drive, which means the touchscreen should be disabled — yet the system behaves as if it’s receiving constant false touch input. When this happens, I cannot back out of screens or use the physical control knob or buttons, making it extremely distracting and unsafe while driving. The dealer initially diagnosed it as a screen laminate issue, which they said isn’t covered under warranty. However, this appears to be a known defect in the CMU (Connectivity Master Unit) that Mazda has not properly addressed in many cases, even though there is an ongoing class action settlement about it. The CMU passed their diagnostic test, but the issue persists — and others have reported receiving full replacements despite passing those same tests. Mazda refuses to escalate or repair unless the screen kit fails first. I believe this is a defect affecting driver safety, especially since it continues while the vehicle is moving.

When accelerating, the transmission feels jerky/stutters. The check engine light and traction control light are illuminated and on the instrument cluster the messages: "Forward Smart City Brake Support Malfunction", "Smart Brake System Malfunction" and "Front Radar Sensor System Malfunction" appear. The vehicle acts like it doesn't know which gear it should be in, it'll buck pretty hard and then it refuses to accelerate...it feels like it's in a "limp mode". A previous driver of the vehicle complained and said that it actually stalled in traffic on the highway and was of course difficult to steer due to loss of power. I took it to a dealership and they came up with a laundry list of things to fix...most of which wouldn't have any bearing on this issue. I did have the serpentine belt replaced and the belt tensioner replaced due to wear on the belt and loose tension. On 7/16/25, I scanned the vehicle with a code reader, the codes P0301 and P0506 appeared. P0301 is a generic "Cylinder 1 Misfire Detected" message and P0506 is a generic "IAC system RPM Lower Than Expected. The vehicle was taken to a shop where the spark plugs and the cylinder 1 coil was replaces and the IAC cleaned. On 7/24/25 the same vehicle behaviors were observed and the same warning lights and messages were activated. I scanned the vehicle and got "p0300 Random/Multiple Cylinder Misfire Detected and P0304 Cylinder 4 Misfire detected. There was a recall on this particular vehicle make, model and year and my vehicle was out of the VIN# range. I firmly believe that the recall needs to be expanded to include a larger number of vehicles...you can google about this vehicle and see many others with similar issues. Usually, the cure is a PCM reflashing/software update that seems to take care of the issue. Please expand the recall before someone dies in an accident because of this problem.

We had another CX-5 in the back that we used to test whether or not it was either the throttle body or the BCM ( Body Control Module ) or the PCM ( Power Control Module ) not working that is causing your vehicle to not wanting to turn on The throttle body passed we transferred it over from vehicle A ( Being the donor ) to vehicle B (Being your vehicle ) and it was still doing the same thing which it would crank but not fully turn on and that is how we ruled that part out The BCM we also transferred over from vehicle A to vehicle B and same thing it would crank but not fully turn on This is what the mechanic at Mazda Collision Center of Irving stated: The PCM has power and is communicating with everything else in the vehicle. If it was the PCM then nothing would work and we wouldn't be able to even cycle the power as if we were going to turn on the vehicle We brought this over to our Mazda Foreman and we showed him the codes it was throwing and what was going on and explained everything and he did tell us that it could be the main harness that is causing all of this he is not for sure just because he is not the mechanic involved in this but he said that is a good start. I am uncertain exactly what is wrong with the vehicle. When I took it in to be serviced, it worked. The mechanic then said he couldn't work on it anymore after trying to fix the body work because the electrical system had failed. I then had it towed to Mazda to see if they could fix the issue. I had originally took it in because of a minor fender bender. I am unclear as to why it has taken four months and my car still doesn't work and I do not know how to afford buying a car to replace it when I cannot trade it in since we cannot resolve the electronic portion through insurance.

Critical Malfunction- causing parking brake malfunction, anti lock brake system malfunction, Dynamic stability control malfunction, Disabled blind spot monitoring, Keyless entry system malfunction, Front brake / and obstruction warning disabled, Keyless entry system malfunction, Air Bag system and seat belt pre-tensioner system malfunction. Vehicle not starting./dead. Sat at dealership service where purchased for 6 days saying they could not test bc they did not have a battery tester- Magically when I complained they found one- and say everything checks out ok. Vehicle is not safe!!!! If this malfunction happened while driving I could have been killed. The dealership refuses to anything g but say it’s OK- and it’s not a lemon. I cannot put my life at risk and they will not guarantee it will not happen again- or say why it happened- other than check g the battery.

The radio changes stations by itself, speakers/music goes in and out. The screen freezes and cannot change stations. And also the car lags on taking off sometimes. Often smells like fuel when you turn on the car, Assuming a fuel pump issue, not sure. I spoke to the salesman who sold me the car (adam) within less than 30 days of having the vehicle and told me the electrical issue with radio would be covered. Then when I called to have the issue fixed I was told it wasnt going to fixed on their behalf. This car was sold to me with a few issue that I was not aware at the time of purchase.

*This is not part of the class action lawsuit* Per attorneys for the complaint, this issue is not part or covered by that lawsuit* This is concerning the infotainment system and what is known by Mazda as “ghosting”. Mazda for safety disables touch screen while car is out of park or driving. The ghosting issue ( which simulates touching of the screen) has overridden the safety lock out feature. While driving or in gear, the ghosting issue will increase radio volume to max, start beeping, changing different features, place calls etc. This sudden unexpected “ghosting” startled me and distracted me from safe driving. This can lead to accidents. Mazda is aware of this issue as they issued a warranty extension due to a previous complaint with the NHTSA in 2019. However, Mazda did not change the defective part/s in their vehicles and the issue continues on 2020 models. In my 2020 Mazda CX-5 this issue has been happening for approximately 2 years getting progressively worse.

While driving down highway the car suddenly will stop accelerating. Once this occurs the check engine light will turn on and shortly after the battery light will turn on. The car will not move and the AC will then stop working. The first time the car was brought to dealership (under warranty). They had to replace battery, fuel pump and fuel level indicator. They stated the fuel pump was broken as was the fuel level indicator. They were able to reproduce the problem prior to fixing it the first time. Less than a month after the car was repaired the exact same issue happened. This is a significant safety concern as I was driving on the highway with a [XXX] child in the back seat when the car stopped driving the second time. I was barely able to get over a lane and off the road before the car stopped driving. The AC then stopped working on a day where the feels like temperature was over 100. I had to lay wet cloths over my infant to prevent her from overheating while we waited for AAA and a family member to reach us. The inability to accelerate/sudden stopping of the car while driving on a highway with a speed limit of 70mph posed a significant safety risk to my life, my child’s life and potentially other cars if they weren’t able to stop. I had to wave frantically at the car in the lane next to me so that they wouldn’t hit me. No warning lights came on until after the issue (stopped accelerating) occurred. The dealership (Mazda) now has the car again and will be inspecting it. I have files from the first incident however they are in the car. Once I get my car back I can send over the reports of what they replaced/work completed. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)