Mazda CX-9 check engine light comes on

Filed Nov 4, 2026 · Engine · 86,000 miles · NJ

The contact owns a 2021 Mazda CX-9. The contact stated that while driving approximately 20 - 25 MPH, the check engine warning light illuminated. The contact used a diagnostic scanner and retrieved DTC: P0303, for a cylinder #3 misfire. The vehicle was taken to a local Mazda dealer to be diagnosed and repaired. The dealer found a coolant leak and performed a system cleaning and replaced the spark plugs and fuel injectors. However, the failure reoccurred. While the contact's wife was driving the vehicle, the check engine warning light illuminated, and the vehicle was towed to the dealer by the insurance company. The contact requested that the dealer inspect the cylinder head gasket and coolant system in his presence. The dealer informed the contact that the repair warranty would be limited to one year or 12,000 miles. The contact also contacted the manufacturer customer service but was not provided any additional assistance. The failure mileage was approximately 86,000.

Filed Jun 18, 2026 · Engine · MA

Check engine light comes on and error P0303 comes on. Had an independent mechanic do the following and after each one, error P0303 still came on 1. Swap the ignition coils from 2 to 3 2. Swap spark plugs from 2 to 3 3. Swapped injectors 4. Compression test 5. Leak down test 6. Changed the spark plug, coil and injectors 7. Looked for vacuum leaks. Mechanic believes that it is related to the cracked cylinder head in the recall, MC-10232269-0001.pdf. My vehicle is just outside of the recall range and has 87k miles on it. Other research online shows other people with the same vehicle and similar milealge are also having this problem.

Filed Jun 5, 2026 · Fuel system · NC

Engine running rough. Check Engine Light illumination. Difficulty starting or a no-start condition. Noticeable loss of power during acceleration Check engine light P0192

Filed Mar 5, 2026 · Engine, Suspension · 188,000 miles · GA

The contact owns a 2013 Mazda CX-9. The contact stated that while driving at an undisclosed speed, the vehicle shuddered abnormally. The check engine warning light was illuminated. The vehicle was taken to a dealer, where it was diagnosed, and determined that the lower control arm needed to be replaced. The vehicle was repaired; however, the contact had not received documentation of the repair. The manufacturer was notified of the failure and informed the contact that the vehicle was repaired under an undisclosed recall. The failure mileage was approximately 188,000.

Filed Dec 11, 2025 · Steering · MA

The car was jump start due to a bad battery it cold and the light was left on. Right after the jump start a check engine light can on. When I put the vehicle in drive to turn the steering wheel it violently snapped bad and broken one of my finger nail. I tried aging in disbelief it happened aging this shouldn't be happening it could've broke my fingers.

Filed Jun 10, 2025 · Engine, Fuel system · VA

The vehicle will hesitate/stall while driving down the road. The vehicle has done this multiple times and has actually shut off on 2 different occasions while at a stop. on 2 occasions now the vehicle has not wanted to start. I have taken vehicle to Mazda dealership and they can never duplicate it. When they check for any codes, the vehicle computer does not give accurate times when happened. This last date I took it to them 6/9/25, the computer said it happened 4000 miles ago. The time before, I took it in the morning it happened, 5 min after it happened and the computer said it happened 10 starts ago. The last time, 6/9/25 they said they suspect fuel pump going bad, but until the vehicle gives a "check engine" light or dies all together they are not 100% sure. The vehicle is unsafe if it dies in the middle of the freeway/road with no warning to myself or the other vehicles around me. This has been going on for at least 1 year now, maybe longer Dealership has all records. Seeing how the 2018 & 2019 Mazda CX-9 had fuel pump recalls makes me wonder if the 2020 should have been included in this recall. This has been an on going problem.6/7/25 was most recent incident.

Filed Mar 28, 2025 · Engine, Suspension · CO

Failed water pump, blown head gasket, major coolant leak, and warped head causing the vehicle to overheat and die when coming to a stop. Vehicle died when stopped in construction on a highway and we were nearly rear-ended. Vehicle never showed check engine light and temperature gauge never showed that vehicle was overheating but significant damage was caused to the engine from “excessive temperatures.” Failure of warning signals allowed us to continue driving the car with a significant engine issue. Now the entire engine needs replaced at only 83,000 miles. Car was diagnosed by licensed independent repair shop. Additionally, front struts went out at approximately 40,000 miles making the car wobble at higher speeds. Was inspected and replaced by dealership.

Filed Mar 26, 2025 · Engine, Steering · PA

I was driving the vehicle on the highway when the vehicle started to overheat, lights started blinking, the car was smoking, losing power and acceleration. This car has a recall on the cyclindwr head which when cracks causing the car to loose coolant and oil. If it cracks while you’re driving especially on the highway the car will immediately loose coolant and oil thus causing a very dangerous driving condition. There was no indicator prior to the failure that there was anything wrong with the car. No check engine lights, no coolant lights nothing. Prior to this happening I smelled coolant in the car cabin , took it to my mechanic who tested the coolant system and found no leak. At the time he was unaware of the known issue these cars have with the cylinder head. The problem has been confirmed by Mazda and they notified me within the month of March of the problem and the extended warranty to replace the known manufacturer defect cylinder head. The Mazda dealer now has my car and acknowledges the cracked cylinder head caused the problem but said because I didn’t immediately stop on the highway and kept driving until I got to a safe location I was negligent and are refusing to fix the car which now has a blown engine, etc. it is available for inspection now at the Mazda dealer. My safety was put at risk because I could have died on the highway if the car completely stopped working, it was dangerous driving it when it first started happening because it started out of nowhere the car was fine I was driving 50+ mph and it started smoking, overheating etc. I could have also killed someone else. It is a disgrace that not only they won’t fix my car they want to say they won’t because I’m negligent? I drive my kids to and from school everyday do you think I’m going to risk their safety in an unsafe car? They should not only fix the car but compensate me for putting mine and my children’s lives at risk. A complete disgrace.

Filed Oct 20, 2024 · Engine · AZ

I purchased a 2018 Mazda cx9 from a local used car dealer several weeks ago. Check engine light came on after a few weeks for cylinder 3 misfire and there was a steep decline of the vehicle performance (hard start, rough idle, lower mpg, sluggish driving). Took it to Berge Mazda who charged me for diagnostics/spark plugs, and ignition coil. They informed me the next steps were a compression tests, fuel injectors and if that didn’t fix the problem then they wanted to strip down the engine to evaluate the cylinder head. At this point I decided to take it to my local mechanic who I trust, he diagnosed a cracked cylinder head. Now I’m stuck with a car I just bought that’s unsafe to drive needing a 6-8k repair. Upon further research there is a widespread problem with Mazda’s manufacturing of there cylinder heads on certain models (including the 2018 Mazda cx9). This is confirmed by TSB’s from Mazda along with a class action lawsuit recently filed. Upon more research on my vehicles history, I gathered that my vehicle was traded into Horne Mazda and then a couple days later auctioned to the used car dealer I bought it from. The fact that Mazda is selling off their own defective vehicles that are unsafe at auctions is absolutely disgusting and something needs to be done about it.

Filed Oct 9, 2024 · Engine, Fuel system · TX

- My 2018 Mazda CX 9 started stalling and jittering at idle and then eventually during slow driving. - Next day I got a check engine light, took to Mazda service center at the dealership I have been going to for last 6 years since I bought the car. - Service center diagnosed that there was a coolant leak through the cylinder head which seems to have cracked. - Further investigation indicated that this has been identified on many other similar Mazda engines and a Technical Service Bulletin had been issued by Mazda to Dealers. - On probing initially, dealership declined they were aware of any such problem. - The amount of repair for the engine replacement (cylinder head and other parts) is exuberant and is almost half of the value of my car, and is not expected for a low 44,000 miles car. - This had posed safety issue for my family since the stressed engine with leak in cylinder head could lead to fire and fatality. - I am awaiting response from Dealership and Mazda corporation case#[XXX] for a response especially when this issue has been filed under a class action lawsuit: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)