2016 Mazda CX-9

The cylinder head (which involves the engine cooling system) has a known manufacturer defect that affects all year/models of the Mazda CX-9 with turbo. The manufacturing defect poses a risk to motor vehicle safety in a group of vehicles or equipment of the same design and/or manufacturer. Specifically, the overheating and failure of the engine can occur at any time, without warning. This puts my family at risk of being stranded on a roadway, particularly because my car is often driven in rural areas. The manufacturing defect is significant and is acknowledged by Mazda: Mazda has offered owners a voluntary, limited, warranty extension (CSP11) of 10 years or 120,000 miles. The voluntary warranty extension is not sufficient because it is limited in duration while the safety risk can happen at any time after the warranty extension expires. The warranty extension essentially only applies to about half of the expected lifetime of the car. NHTSA should determine that a recall and repair should be issued by Mazda that does not expire. The engine is defective, poses a safety hazard, and Mazda has fixed the engine for subsequent models (starting in 2021), so a repair is available.

NHTSA ID

11734209

Incident

Apr 27, 2026

I own a 2016 Mazda CX9 Touring FWD (180k miles). Today my car was diagnosed with cracked cylinder head, resulting in coolant and oil leak from the head gasket. While there is a class action settlement about it where Mazda accepted the manufacturing defect, they do not cover the engine repair/cylinder head replacement because my car's mile is over 120k. If it is a manufacturing defect, why year/mile make a difference on the responsibility of the manufacturer? Mazda obviously sold defect vehicles to their customers, and driving these vehicles under this condition is very dangerous! Now, they are expecting me to pay more than $10,000 for a vehicle priced around $6,000!

NHTSA ID

11706610

Incident

Dec 22, 2025

In June of 2022 I started having a strong antifreeze/engine coolant smell inside the cab of my vehicle and also outside the vehicle. I had the car checked for a radiator leak, but there wasn’t one. I took my car into my local Mazda where they found that the engine coolant was leaking into the heads of the engine. Mazda kept my car for 5 months and repaired the problem, it cost me $4000 and they had added a 12 month 12,000 mile warranty for the parts. My car is a 2016 Mazda cx-9 at the time of the repair it had 70,430 miles on it. Now a few years later I am having the same issue with the coolant smell inside the cab and outside my vehicle, it goes into the shop for diagnosis on Monday November 10,2025. The car now has 118,000 miles on it. I had purchased an extended warranty for the car at the time of purchase but it had timed out a month before I took my car in for the first repair….please Mazda stand behind your vehicles I am a senior woman with very little income and I will not be able to pay out of pocket for this repair and I CANNOT afford a new car… I would like to get reimbursed for my out of pocket on the first repair and get my car repaired this time as well under a warranty.

NHTSA ID

11697196

Incident

Jun 30, 2025

Cylinder head crack. Combustion gasses leaking into coolant causing overheat. Combustion gasses bleeding into oil causing excessive crankcase pressure.

NHTSA ID

11695620

Incident

Oct 25, 2025

The contact owns a 2016 Mazda CX-9. The contact stated that while driving approximately 45-50 MPH, the vehicle suddenly lost motive power with white smoke coming from the front of the vehicle. The contact was able to get to the side of the road to inspect the vehicle and became aware that there was coolant splattered all over the engine compartment. The failure had occurred twice. The “WRENCH” symbol was displayed with the “Service Vehicle” message displayed. The vehicle was taken to the dealer, who diagnosed that the coolant pump and water pump were leaking, and the radiator needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The manufacturer opened for the failure. The failure mileage was approximately 148,000.

NHTSA ID

11687565

Incident

Oct 15, 2024

Mileage

148,000 mi

Smart City Break Malfunction warning light appears while driving. Simultaneously the tire pressure warning appears. Also, at the same time, the temperature reads -20 to -40 degrees. Yes, vehicle is available for inspection. Fearful that car could randomly break while driving putting myself and family in danger since there is a malfunction. Mazda service center says the problem can’t be reproduced so there’s nothing they can do. The problem seems to appear when the outside temperature is 60 degrees Fahrenheit or higher.

NHTSA ID

11656449

Incident

Jun 1, 2024

Engine failure with crack in the engine after a loss of coolant fluid.

NHTSA ID

11632664

Incident

Dec 19, 2024

Head gasket leaking and caused major engine issue at 89,000 miles. Mazda has known of this issue, but refuses to recall it.

NHTSA ID

11626600

Incident

Sep 26, 2024

This SA supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-061/25 12/17/25 DESCRIPTION If you encounter any type of electrical concern (e.g, dead battery, engine no start, DTC(s) stored...), interview the customer before proceeding with normal MGSS diagnosis by asking if any aftermarket devices have been installed. Aftermarket devices may be the cause of the electrical concern. Below are a few examples of unusual electrical concerns caused by aftermarket devices. Examples: 1. Devices connected to the DLC-2 (battery discharge/DTC stored) 2. Devices plugged into the 12V outlet 3. GPS tracking device (engine no start/battery discharge) 4. Dash cam (DTC stored) 5. Non-certified USB cable (Apple Carplay™/ Android Auto™ will not connect) 6. Over-sized wheels/tires (incorrect GPS location) 7. DTC C0023:14 8. Decorative trim and/or cover on the START/STOP ENGINE button Example 1: Some electrical devices connected to the DLC-2 connector by insurance or mobile phone companies may cause: Battery discharge. The device may disrupt the CAN system battery saver mode. • IDS/MMDS will not communicate with the vehicle due to poor DLC-2 connection. The aftermarket device may cause DLC-2 female terminals to spread open.

This bulletin supersedes the previously issued bulletin(s) listed below. The changes are noted in Red. 01-008/23 06/05/23 Some vehicles may exhibit rattling noises from the engine compartment and oil leakage from the drive belt auto tensioner. This may be caused by insufficient sealing at the drive belt auto tensioner damper when the auto tensioner fully operates under both high ambient temperature and high load conditions. To eliminate this concern, the shape of the drive belt auto tensioner damper has been changed. REPAIR PROCEDURE If the tensioner is found to be "No Good" after completing the Drive Belt Auto Tensioner Inspection, replace it with a modified part according to the instructions on MGSS online:

DESCRIPTION Some vehicles may require the replacement of a damaged VIN plate or vehicle certification label. To obtain a replacement VIN plate (bulkhead-mounted and visible through the lower-left area of the windshield), contact DAG (Dealer Assistance Group) using VIN Plate Request Form available on One Mazda. To obtain a replacement vehicle certification label (located on the B􀀀pillar or front door), contact your assigned DSM (District Service Manager) to place the order. If DSM contact information is not available, refer to the Dealer & Field Contact Directory.

This Service Alert supersedes the previously issued SA listed below: The changes are noted in Red. SA-011/24 02/12/24, 06/06/24, 07/29/24 DESCRIPTION Mazda has developed factory recommended scheduled maintenance services that support all major vehicle systems. Mazda recommends dealers follow the scheduled maintenance tables as cited in the vehicle-specific workshop manual or owner's manual. Services performed outside of Mazda's factory scheduled maintenance are not recommended. These services are unnecessary and create unneeded expenses for your customers. SCHEDULED MAINTENANCE Refer to the applicable Workshop Manual or Owner's Manual for vehicle -specific manufacturer scheduled maintenance. Workshop Manual - Refer to section 00-00 SCHEDULED MAINTENANCE. Owner's Manual - Refer to section 8 Maintenance and Care. b. Note: Please refer to the information below outlining the services not included in Mazda's Factory Scheduled Maintenance: IMPORTANT: Recommending fluid flushes when not necessary can lead to customer confusion and dissatisfaction. Fluid flushing for preventive maintenance purposes is strongly discouraged, unless otherwise specified in a published procedure (Owner’s Manual, Workshop Manual, Technical Service Bulletin, etc.).

This Service Alert supersedes the previously issued M-Tip(s) listed below. The changes are noted in Red text. MT-002/19 09/30/19 and 12/19/19 DESCRIPTION If an engine assembly is replaced after a catastrophic internal mechanical failure, clean the intake manifold internally before installing a replacement engine assembly. If the intake manifold is not cleaned properly, the replacement engine may fail prematurely. Metallic debris from the old engine (with catastrophic internal mechanical failure) may rest inside the intake manifold. When the new engine assembly is installed, debris in the intake manifold will be ingested into the new engine and cause internal damage. Clean the intake manifold internally to remove any debris from old engine before installing the new replacement engine assembly. If the intake manifold cannot be properly cleaned internally, replace it.

There are currently 2 methods for cutting a new auxiliary key blank. A. Auxiliary Key Trace Cut Method • B. Auxiliary Key Code Cut Method 2019 and newer models require a 10-digit key code to accurately cut keys • 5-digit codes CANNOT be provided for 2019 and newer vehicles (the traditional 5-digit code from the key tag or driver's door lock cylinder is not sufficient and will not be issued for key cutting on these models). • Only Mazda-approved key cutting machines can process these 10-digit codes. • Many older key machines do not support 10-digit codes and cannot be updated to do so. In these cases, dealers will need to purchase one of the newer Mazda-approved key cutting machines capable of handling this requirement. • For a list of current Mazda-approved machines and purchasing options, refer to the Mazda Dealer Equipment Program or view the current Mazda approved key machines below.