The 2018 Mazda Cx 9 carries 2 open NHTSA recalls — most recently covering fuel pump and wiring. Owners report 6 recurring issue clusters, led by “Engine coolant leak from cracked cylinder head.” Mazda's Skyactiv engines use unusually high compression ratios (13:1 to 16:1) and require strict adherence to oil intervals — extending oil life on a Skyactiv engine accelerates carbon buildup on intake valves. Mazda's published Schedule 1 (severe) covers most US driving conditions. Mazda3, CX-5, CX-30, and CX-50 share the Skyactiv-G platform.
FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP
Campaign #21V875000 · Dec 11, 2021
Issue: Mazda North American Operations (Mazda) is recalling certain 2018 Mazda3, Mazda6, 2019 CX-3, 2018-2019 MX-5, CX-5, CX-9, and 2019-2020 Mazda2 vehicles. The impeller inside the low-pressure fuel pump may crack and deform, potentially causing the fuel pump to fail.
Risk: Fuel pump failure may cause an engine stall, increasing the risk of a crash.
Fix: Dealers will replace the fuel pumps, free of charge. Owner notification letters were mailed July 18, 2022. Owners may contact Mazda customer service at 1-800-222-5500 Option 4. Mazda's number for this recall is 5321K.
ELECTRICAL SYSTEM:WIRING
Campaign #19V403000 · May 30, 2019
Issue: Mazda North American Operations (Mazda) is recalling certain 2018 CX-9 vehicles. The wiring harness may disrupt electrical communications and disable the passenger frontal air bag, turn signals, and/or engine starting system.
Risk: The passenger frontal air bag may not deploy, increasing the risk of injury. Inoperable turn signals prevent the driver from signaling to other drivers, increasing the risk of crash.
Fix: Mazda will notify owners, and dealers will repair the wiring harnesses, free of charge. The recall began July 26, 2019. Owners may contact Mazda customer service at 1-800-222-5500, Option 4. Mazda's number for this recall is 3419E.
What drivers and federal regulators have officially reported about the 2018 Mazda Cx 9.
ENGINE
71 NHTSA complaints · 2022-06 → 2026-06
“The cylinder head cracked and leaked engine coolant at 72K miles. This is a known design flaw IAW TSB 01-007/22. Vehicle overheated.”
“coolant leaks at cylinder head , Mazda of America knows issues but not willing to recall , they hava a bulletin number 01-002/23 . pls help”
UNKNOWN OR OTHER
14 NHTSA complaints · 2021-06 → 2025-07
“After sitting in the heat of summer, cracks appeared on two of the corners of the LCD navigation screen making it very hard to see portions of the screen.”
“the Mazda Connect information screen has small spider cracks on the upper right part of screen that are inside the glass (if you run your finger over the crack it feels smooth). Information websites pertaining to Mazda vehicles say it's caused by temperature change.”
ELECTRICAL SYSTEM, SERVICE BRAKES, FORWARD COLLISION AVOIDANCE
6 NHTSA complaints · 2020-07 → 2025-09
“I am submitting this recall request because my vehicle has experienced repeated incidents of a serious safety issue. While driving—most often on the highway—a warning appears that says “Smart System Brake Malfunction.” Immediately after, the car begins braking on its own…”
“I keep getting a automatic emergency braking malfunction alert”
FUEL SYSTEM, GASOLINE
4 NHTSA complaints · 2018-07 → 2022-06
“When this vehicle is low on fuel (but not empty) and under heavy acceleration, the fuel pump temporarily fails causing the engine to stall. This creates a serious safety hazard. Other 2019 Mazda models were covered for a similar defect under NHTSA Campaign Number 21V-875,…”
“The contact owns a 2018 Mazda CX-9. The contact stated that while pulling up to a gas pump the vehicle lost motive power and stalled. The contact added gasoline to the vehicle, restarted the vehicle, and was able to continue to drive to her residence…”
UNKNOWN OR OTHER, SERVICE BRAKES, ENGINE
3 NHTSA complaints · 2019-07 → 2022-12
“HAPPENED TO ME TWO TIMES IN PAST THREE WEEKS, WHERE I AM COMING TO A STOP, OR HARDLY MOVING, AND CAR SUDDENLY ACCELERATES. HAD MY FOOT ON THE BRAKE AND THE CAR WAS STILL TRYING TO ACCELERATE. YESTERDAY, 4/24/21 IT TOOK ALL MY STRENGTH ON THE BRAKE TO KEEP THE CAR FROM PULLING…”
“I was resting my foot on my brake in the middle of sealed traffic and when I eased up to move forward when traffic my brakes did stop causing me to bump the car ahead of me. After that what came next was that my car then accelerated forward with my foot still on the brake…”
SEATS
2 NHTSA complaints · 2026-01 → 2026-06
“Passenger seat heater either had a grounding issue or shorted out, causing to seat to start smoldering and catching fire, destroying the seat. There has been recalls and lawsuits for this specific issue on this model in other years, but not for this model year.”
“My passenger heated seats malfunction while I was driving. As I was driving on the highway I smelled something burning. I didn't know where the smell was coming from it was strong . Then while I'm driving on the highway my seat started to smoke a lot I got scared and pulled…”
Issues on other model years
Source: NHTSA Office of Defects Investigation (ODI). Complaint data refreshed Sep 11, 2026. Investigation data refreshed Sep 11, 2026.
We display NHTSA's record with attribution; we don't editorialize on what these complaints mean for any specific vehicle.
Critical for safety and preventing major damage
Replace 0W-20 full-synthetic oil every 5,000 miles under Schedule 1. Schedule 2 (highway-only): 7,500 miles. Mazda CX-50 Turbo and CX-9: 5,000 miles regardless of schedule.
Estimated cost — typical U.S. ranges
Dealer
~$120–$160
Shop
~$85–$115
DIY
~$25–$55
Full synthetic costs more than conventional. 5-quart 0W-20 + filter is the typical bill.
Rotate tires every 7,500 miles. AWD CX-5, CX-50, and CX-9: 5,000 miles to prevent uneven wear from front-biased AWD coupling.
Estimated cost — typical U.S. ranges
Dealer
~$85
Shop
~$60
DIY
Free
Often free at the shop where you bought the tires — worth asking before paying.
Inspect brake pads, rotors, and parking brake at every oil change. Mazda3 and CX-5 front pads typically last 35,000-50,000 miles.
Estimated cost — typical U.S. ranges
Dealer
~$85
Shop
~$60
DIY
Free
Most shops do this free as a courtesy with any service. Don't pay separately if you can avoid it.
Replace DOT 3 brake fluid every 30,000 miles or 36 months.
Estimated cost — typical U.S. ranges
Dealer
~$180–$200
Shop
~$125–$140
DIY
~$10–$25
DOT 3 or 4 — match the cap. Vacuum bleeders make this a one-person DIY.
Keeps your vehicle running smoothly and efficiently
Replace engine air filter every 30,000 miles. Skyactiv-G direct injection is sensitive to airflow restriction — inspect at every oil change.
Estimated cost — typical U.S. ranges
Dealer
~$60–$95
Shop
~$45–$70
DIY
~$15–$40
5-minute job on most cars; the airbox lid usually has clips, no tools needed.
Replace ATF every 60,000 miles severe / 100,000 normal. Use Mazda FZ ATF — substitutes cause harsh 1-2 shifts and torque converter shudder.
Estimated cost — typical U.S. ranges
Dealer
~$330–$500
Shop
~$235–$355
DIY
~$60–$180
Some sealed transmissions have no dipstick — fill is precise and best left to a shop. Many drivers can still DIY drain-and-fill.
Iridium spark plugs every 60,000 miles on Skyactiv-G 2.0L and 2.5L. CX-50 Turbo and CX-9 Turbo: 45,000 miles.
Estimated cost — typical U.S. ranges
Dealer
~$285–$390
Shop
~$200–$275
DIY
~$25–$100
Iridium plugs cost more but last 100k+ miles. V6/V8 access varies wildly — some are tough.
Mazda FL-22 (yellow): first change at 120,000 miles or 10 years, then every 60,000. Do not substitute — silicate-free formula prevents water pump damage on Skyactiv engines.
Estimated cost — typical U.S. ranges
Dealer
~$285–$330
Shop
~$200–$235
DIY
~$25–$60
Use the manufacturer-specified coolant — wrong color/chemistry can damage the cooling system.
AWD CX-5, CX-50, CX-9: replace transfer case fluid and rear diff fluid every 60,000 miles.
Estimated cost — typical U.S. ranges
Dealer
~$105–$140
Shop
~$75–$100
DIY
~$15–$40
AWD/4WD vehicles only. Easy drain-and-fill on most platforms.
Extends the life of your vehicle and improves comfort
Replace cabin air filter every 15,000 miles. Behind the glove box on Mazda3, CX-5, CX-30, and CX-50.
Estimated cost — typical U.S. ranges
Dealer
~$60–$95
Shop
~$45–$70
DIY
~$15–$40
Usually behind the glovebox. Shops charge labor for a 10-minute job — easy DIY win.
Occupant deaths in fatal crashes (FARS)
7 crashes 2010–2024
FARS counts every occupant death in a fatal crash, whatever the cause — it does not mean the vehicle was at fault or defective. Counts are not adjusted for how many of each vehicle are on the road. How to read this number
Owner-reported problem signals
Separate from the federal fatality data above: complaints owners filed with NHTSA about this year and model. These are reports of problems, unverified, and are counted here only as signals.
4
complaints mentioning a crash
1
complaints mentioning a fire
Reviewed known issues for this vehicle·Open recalls for this vehicle
Typical U.S. ranges. Actual quotes vary by shop, parts choice, and vehicle condition.
How we estimate: Dealer = OEM parts × 1.4 + labor × $165/hr. Shop = parts + labor × $115/hr. DIY = parts only.
This maintenance schedule for the 2018 Mazda Cx 9 reflects Mazda's published service intervals. Your actual service needs may vary based on driving conditions, climate, and vehicle usage. Always consult your owner's manual for model-specific recommendations.