SEATS:MID/REAR ASSEMBLY
Defect Description
Mazda North American Operations (Mazda) is recalling certain 2020-2021 CX-9 vehicles equipped with 60/40 split bench second-row seats. The left-side second-row seat may unexpectedly slide forward during a crash. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle
... Safety Standard number 210, "Seat Belt Assembly Anchorages."Read moreConsequence
A seat that slides forward during a crash can transfer excessive force onto a belted occupant, increasing their risk of injury.
Remedy
Dealers will replace the internal parts of the affected second-row seats, free of charge. Owner notification letters were mailed November 4, 2021. Owners may contact Mazda customer service at 1-800-222-5500, Option 4. Mazda's number for this recall is 5221I.
8,648 vehicles affected
Manufacturer: Mazda North American Operations
SEAT BELTS:REAR/OTHER
Defect Description
Mazda North American Operations (Mazda) is recalling certain 2020-2021 CX-9 vehicles equipped with 60/40 split bench second-row seats. The left-side second-row seat may unexpectedly slide forward during a crash. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle
... Safety Standard number 210, "Seat Belt Assembly Anchorages."Read moreConsequence
A seat that slides forward during a crash can transfer excessive force onto a belted occupant, increasing their risk of injury.
Remedy
Dealers will replace the internal parts of the affected second-row seats, free of charge. Owner notification letters were mailed November 4, 2021. Owners may contact Mazda customer service at 1-800-222-5500, Option 4. Mazda's number for this recall is 5221I.
8,648 vehicles affected
Manufacturer: Mazda North American Operations
Complaint Statistics
23 total complaints
Top Reported Components
| Component | Complaints |
|---|
| ENGINE | 5 |
| ELECTRICAL SYSTEM | 4 |
| UNKNOWN OR OTHER | 3 |
| POWER TRAIN | 2 |
| FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING | 2 |
| SERVICE BRAKES | 2 |
| STRUCTURE:BODY | 1 |
| VISIBILITY/WIPER | 1 |
| FUEL/PROPULSION SYSTEM | 1 |
| TIRES | 1 |
Incident date: Mar 9, 2026
Warning signal front camera sensor system malfunction Forward Smart City Brake Support malfunction When this initial happen the steering wheel becomes hard to maneuver than releases The front and back cameras are clear from any debris or obstructions What should I do next?
Incident date: Feb 17, 2026
All 4 of my BH255/50R20 XL 109v NOKIAN WR G4 vehicle tires are exhibiting abnormal tread degradation and excessive sidewall cracking. The tire defect includes a circumferential crack along the top of all 4 tires, where the top of the tire's sidewall and tread base meet. Upon tire inspection, the str
... uctural integrity and safety of these tires with continued usage is questionable. The tires in question are only 26 months old and have approximately 31K miles of usage.Read more
Incident date: Mar 1, 2025
The information screen is getting 'spider cracks" spreading across the face and turning opaque making the information unreadable. Mazda is apparently aware of this defect and issued a TSB for earlier models. Dealers were unhelpful and quoted $1000 - $3000 to repair depending on the VIN.
Incident date: Mar 1, 2025
The information screen is getting 'spider cracks" spreading across the face and turning opaque making the information unreadable. Mazda is apparently aware of this defect and issued a TSB for earlier models. Dealers were unhelpful and quoted $1000 - $3000 to repair depending on the VIN.
Incident date: Jun 7, 2025
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.Read more
Incident date: Jun 7, 2025
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.Read more
Incident date: Jun 7, 2025
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.Read more
Incident date: May 29, 2024
Vehicle randomly displays "smart brake system malfunction," "forward smart city brake malfunction" and " front radar system malfunction." This has been going on for at least a year. I will be driving on a highway, trying to accelerate and these messages will pop up. I'm not able to accelerate when t
... hese messages pop up and I have to turn on my hazard lights and pull over to the side of the road. The only thing that clears these warnings are for me to completely shut down my car and restart it. Luckily I have been able to get over to the side of the road on the highway without an accident, but these warning lights pop up when it's sunny out and there is no reason for the car to act the way it does. I took my car to the dealer the first time it happened and paid several hundred dollars for them to tell me that they don't know why it happened. There are several forums posted online with people having the same issues. Online posts say to make sure the sensors are clean and that the malfunction can activate if it's too hot, rainy, snowing or foggy? In my experience, it has happened only when it has been sunny. When the system decides to malfunction, the car will not accelerate, and it could make it easier for the car to be hit by another car. It's like the car just shuts down.Read more
Incident date: May 29, 2024
Vehicle randomly displays "smart brake system malfunction," "forward smart city brake malfunction" and " front radar system malfunction." This has been going on for at least a year. I will be driving on a highway, trying to accelerate and these messages will pop up. I'm not able to accelerate when t
... hese messages pop up and I have to turn on my hazard lights and pull over to the side of the road. The only thing that clears these warnings are for me to completely shut down my car and restart it. Luckily I have been able to get over to the side of the road on the highway without an accident, but these warning lights pop up when it's sunny out and there is no reason for the car to act the way it does. I took my car to the dealer the first time it happened and paid several hundred dollars for them to tell me that they don't know why it happened. There are several forums posted online with people having the same issues. Online posts say to make sure the sensors are clean and that the malfunction can activate if it's too hot, rainy, snowing or foggy? In my experience, it has happened only when it has been sunny. When the system decides to malfunction, the car will not accelerate, and it could make it easier for the car to be hit by another car. It's like the car just shuts down.Read more
Incident date: May 29, 2024
Vehicle randomly displays "smart brake system malfunction," "forward smart city brake malfunction" and " front radar system malfunction." This has been going on for at least a year. I will be driving on a highway, trying to accelerate and these messages will pop up. I'm not able to accelerate when t
... hese messages pop up and I have to turn on my hazard lights and pull over to the side of the road. The only thing that clears these warnings are for me to completely shut down my car and restart it. Luckily I have been able to get over to the side of the road on the highway without an accident, but these warning lights pop up when it's sunny out and there is no reason for the car to act the way it does. I took my car to the dealer the first time it happened and paid several hundred dollars for them to tell me that they don't know why it happened. There are several forums posted online with people having the same issues. Online posts say to make sure the sensors are clean and that the malfunction can activate if it's too hot, rainy, snowing or foggy? In my experience, it has happened only when it has been sunny. When the system decides to malfunction, the car will not accelerate, and it could make it easier for the car to be hit by another car. It's like the car just shuts down.Read more
Incident date: May 1, 2025
I've had it repaired for over 30+ times. I'm tired of the car not being fixed. The last visit I was told maybe its the way I drive.
Incident date: Apr 12, 2025
The vehicle was overheating and a message came up that power will be reduced. Then it would go away and come up every 3 minutes while driving. I brought it to the service center, we filled it up with coolant and the issue kept coming back this time with a lot of white smoke coming out at vehicle s
... tart up. My mechanic said this is a bigger issue most likely to do with a coolant leak at the cylinder head. There is a technical service bulletin but no recall as of yet.Read more
Incident date: Apr 12, 2025
The vehicle was overheating and a message came up that power will be reduced. Then it would go away and come up every 3 minutes while driving. I brought it to the service center, we filled it up with coolant and the issue kept coming back this time with a lot of white smoke coming out at vehicle s
... tart up. My mechanic said this is a bigger issue most likely to do with a coolant leak at the cylinder head. There is a technical service bulletin but no recall as of yet.Read more
Incident date: Jan 23, 2025
Excessive oil consumption. In less than 3000 miles, I have to add a quart of oil
Incident date: Jul 1, 2023
Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold. There may be cracks at the stud bolt hole or at the outside of the exhaust manifold - from Mazda's TSB. Excessive coolant leak leading to engine-overheating and going into 'limp mode' couldn't drive faster than ar
... ound 30 mph. Mazda has repeatedly declined help with goodwill requests and any further assistance. ref. https: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)Read more
Incident date: May 14, 2023
We were on the freeway and all of a sudden it stopped accelerating and the engine light, sensor light, and sensor warning came on. We could not accelerate, that became disabled and we had to pull over. My husband said our fluid levels were normal and he checked them all in the shoulder of the freewa
... y. We turned the vehicle off then on again and all lights went away and we continued on. This is a safety hazard because the car would not accelerate while we were going 60 mph on the freeway. I quickly took a picture of the dash as this was happening so I can take it to the dealer.Read more
Incident date: May 14, 2023
We were on the freeway and all of a sudden it stopped accelerating and the engine light, sensor light, and sensor warning came on. We could not accelerate, that became disabled and we had to pull over. My husband said our fluid levels were normal and he checked them all in the shoulder of the freewa
... y. We turned the vehicle off then on again and all lights went away and we continued on. This is a safety hazard because the car would not accelerate while we were going 60 mph on the freeway. I quickly took a picture of the dash as this was happening so I can take it to the dealer.Read more
Incident date: Jul 9, 2022
While driving at freeway speed in Oregon, with 85 degrees ambient temperature and A/C inside set to 74 degrees, our CX-9 sunroof exploded outward. The sound was close to a very loud pop, and not the sound of rock/debris impact. At the time of explosion, there were no vehicles nearby and no overpas
... ses from which an object could have dropped. The vehicle had been washed the day before and there was no visible damage to the sunroof. At the time of explosion, the sunroof and interior cover were closed. Upon stopping the vehicle (within less than one mile) inspection showed that nearly no glass fell downward, and approximately 50% of the total sunroof area had blown upward and out of the vehicle. The remainder of the shattered glass was still contained within the frame, with the edges visibly curved upward as though the glass had been pulled away from the car. There were three people in the vehicle at the time (driver, front seat passenger, and middle row passenger behind the driver). The two passengers were asleep and woke abruptly thinking we had been hit by something, as the explosive bang was followed by the sound of air rushing past the hole. There was no sound of glass rattling in the area over the sunroof cover, which seems to indicate glass had not broken inward and then blew out before stopping. I (driver) kept the cover closed and promptly pulled off the freeway to assess damage. I was unable to visit a dealer for warranty assessment due to vacation travel. A phone call to my local dealer did indicate it should be covered under warranty but it has not been inspected, this has not yet been confirmed. I rarely open the sunroof cover and have only opened the sunroof itself 3-4 times since purchase two years prior (2020). I did open the sunroof to give my son fresh air on curvy roads approximately one hour prior. No injuries, but if the cover had been opened we may have had glass falling into the cabin. No other visible or audible warnings occurred.Read more
Incident date: Mar 22, 2022
The passenger rear plastic wheel trim fell off with no incident/ damage
Incident date: Sep 12, 2021
On 10/12/2021 we were driving on and urban street when the vehicle infront of us signaled and initiated a right hand turn. At that point were we traveling approximately 20 mph, and we were driving with active cruise disengaged. When we were around 150 feet behind the vehicle taking a right when our
... CX-9 falsely engaged the emergency braking. Our car with our whole family in it locked up the brakes and stopped in 80 feet short of the car taking a right. The vehicle behind us only managed to stop 10 feet short of hitting us in the rear. It is in the 4 people in our vehicles opinion that this operation was both terrifying and dangerous to use and those following.Read more
Incident date: Jul 27, 2021
The 2020 Mazda completely shut off following an exit from an expressway, turn under a bridge and slow down for a red light. The Mazda electrically shut off and coasted to a braked stop in the center lane of a 3 lane road. The entire electrical system went dead, no exterior lights, signals, instrumen
... t panel or radio. There was no warning, everything electrical just shut off. In a moving traffic situation the car could not maneuver or restart without being placed in PARK. (There is a history of Mazda CX 9's having a similar problem which sent the driver to the local dealership.) The car was restarted by shifting into Park and pressing the start button, all functions appeared normal as the driver moved it to a parking lot to review the situation. The driver was unable to re-create the complete shut down and finished the trip. The driver took the Mazda to the dealer following the incident and was asked to leave the Mazda for observation. The driver was notified by the dealership that the problem was being elevated to the national team for diagnosis. 10 days later the local dealer called the driver and said that they; nor the Mazda engineers in California; could reproduce the system shutting off or find any error codes. They wanted to return the car to the driver with no need for a repair. The driver spoke to the National Mazda help line and the representative was aware of the situation. The representative reiterated that engineers had been unable to find the source for the incident in the computer logs so they could not provide a remedy. The representative offered the driver the choose of a purchase buy back and a discount on the purchase of a new car.Read more
Incident date: Jan 15, 2021
FUEL CAP LIGHT ON IN DEC 2020. OUR CAR MILEAGE ~14,000 MILES . WE BOUGHT BRAND NEW CX9 2020 IN AUGUST. DEALER INSPECTED IT AND FOUND NOTHING WRONG. DEALER REPROGRAMMED IT. A MONTH LATER JAN 1,2021, FUEL CAP LIGHT IS ON ON AGAIN. WE IGNORED IT THINKING IT IS ANOTHER PROGRAM ISSUE. CAR STARTED TO JER
... K AND VIBRATE AT STOP SIGN. WE BROUGHT TO DEALER THE NEXT DAY. DEALER SAID CHARCOAL BOX IS LEAKING. I THOUGHT CHARCOAL BOX SHOULD LAST A LIFE TIME. THEY SAID IT IS NOT UNDER WARRANTY: $680 LATER, THE JERKING/VIBRATING ISSUE IS FIXED. HOPEFULLY THAT IS IT SINCE WE ONLY HAVE THE CAR FOR 5 MONTHSRead more
Incident date: Jan 30, 2020
THE MAZDA CX-9 UNCOMMANDED ENGINE ACCELERATION REPORTED HEREIN DID NOT RESULT IN ANY DAMAGE PRIMARILY BECAUSE IT COMMENCED SEVERAL SECONDS AFTER I BEGAN LIGHT BRAKING WHILE APPROACHING A RED TRAFFIC LIGHT. MY IMMEDIATE RESPONSE WAS TO INCREASE BRAKE PRESSURE; THERE WAS NO NEED FOR ME TO MOVE MY LEG
... OTHER THAN PRESSING HARDER WITH MY FOOT. MY FOOT HAD BEEN OFF THE ACCELERATOR FOR MANY SECONDS WHILE ALLOWING THE CAR TO SLOWLY DECELERATE WHILE COASTING TOWARD TRAFFIC STOPPED AT A RED LIGHT. WITHIN TWO SECONDS OF COMMENCEMENT OF UNCOMMANDED ENGINE ACCELERATION AND WITH THE CAR FULLY STOPPED, I SHIFTED THE TRANSMISSION INTO NEUTRAL. THE ENGINE IMMEDIATELY GENERATED THE NOISE OF VERY HIGH RPM. ALTHOUGH THE DASHBOARD INCLUDES A TACHOMETER, I DID NOT IMMEDIATELY THINK TO LOOK AT IT; INSTEAD, I TURNED THE IGNITION OFF. A FEW SECONDS LATER, I SHIFTED THE TRANSMISSION INTO PARK AND RESTARTED THE CAR WHICH OPERATED NORMALLY THEREAFTER. MY FOOT DID NOT MOVE OFF THE BRAKE PEDAL DURING ANY OF THE PRECEDING SEQUENCE. ONLY THE NHTSA AND POSSIBLY THE MANUFACTURER WOULD KNOW IF THIS IS A ONE IN A BILLION-HOURS OR A MORE COMMON OCCURRENCE. I AM WILLING TO ANSWER ANY QUESTIONS THE NHTSA OR THE MANUFACTURER MIGHT HAVE. I GRADUATED FROM MIT, WORKED OVER 29 YEARS FOR THE LEADING USA COMMERCIAL AIRCRAFT MANUFACTURER AND AM CURRENTLY RETIRED.Read more
NHTSA Safety Investigations — MAZDA CX-9
Investigations opened by NHTSA into potential safety defects. These are separate from recalls and may or may not result in a recall.
PE — Closed
— Model Year: 2013
Inadvertent Curtain Air Bag Deployment
The Office of Defects Investigation (ODI) opened this Preliminary Evaluation (PE19-006) on May 2, 2019 to investigate two Vehicle Owner Questionnaires (VOQs) and Early Warning Reporting data related to allegations of inadvertent deployment (IAD) of side curtain airbags in Model Year (MY) 2010 throug
... h 2013 Mazda CX-9 vehicles. ODI sent an Information Request (IR) to Mazda North America Operations, LLC. to gather information about the alleged defect in the subject vehicles. In the 20 months since opening the PE, ODI has received three additional VOQs. To date, there have been a total of 11 IAD incidents within the identified population of 104,360 vehicles. Of the 11 incidents, no serious injuries were reported. The last known incident occurred in December 2020.Mazda's response to ODI's IR letter identified the root cause as a manufacturing issue of the Bosch SMG076 Roll Rate Sensor within the Restraint Control Module (RCM). During the manufacturing calibration process, small particles may be generated that could affect roll sensor capacitance, which could lead to a loss of curtain airbag protection or an erroneous deployment command. On November 19, 2012, a revised Roll Rate Sensor calibration process was launched, establishing a clean point for the issue. In its responses to ODI, Mazda has assessed the condition as a low risk to motor vehicle safety, with low incident frequency not warranting action. Any RCM data indicating a malfunctioning Roll Rate Sensor will result in the illumination of the airbag warning light. In the event of an erroneous curtain airbag deployment, there is no contact with properly seated occupants. Additionally, the condition is not affected by deterioration or wear, and known incidents established a random pattern of occurrence.During the investigation, ODI examined the injury risk to vehicle occupants from curtain airbag deployments. It was determined that the subject vehicles do not pose a substantial risk to out of position occupants, as testing data falls within Technical Working Group (TWG) reference values. Modeling simulation based on data provided by Mazda for properly seated occupants during static and dynamic airbag deployments indicated sufficient head clearance and no risk of brain injury. ODI analysis reveals that inadvertent deployment incident rates of curtain airbags in the subject vehicles are low through approximately ten years in service. Incident frequency does not meet values warranting recall action, but rather align closely with baseline frequency of general inadvertent deployments which are known to occur in rare driving conditions. Additionally, warranty analysis of RCM failures resulting in a loss of curtain airbag protection revealed low claim rates.Based on the analysis conducted, this investigation has been closed. The closing of this investigation does not foreclose the Agency from taking further action, if warranted, or the potential for a future finding that a safety-related defect exists, based upon additional information the Agency may receive.The five ODI complaints cited above can be reviewed at NHTSA.gov under the following identification numbers: 10905492, 11165925, 11270089, 11310044, 11385219.Read more
PE — Closed
— Model Year: 2009
Lower ball joint separation
In an July 7,2015 letter to NHTSA, Mazda identified a safety defect that could result in lower ball joint separation in approximately 193,484 model year (MY) 2007 through 2014 Mazda CX-9 vehicles (NHTSA Recall No. 15V-451,Mazda 8515G).Mazda indicated that damage to the ball joint boot may allow wate
... r to enter the front suspension ball joint fitting during use which may result in premature ball joint wear and a progressively looser joint.In January 2014, Mazda implemented redesigned lower control arms in production vehicles to improve the durability of the lower ball joints.The redesign involved changing the shape of the top surface of the ball joint boot cover and adding a suspension plate to the undersurface of the knuckle.Mazda's recall will replace the defect lower control arms with the redesigned parts.ODI's analysis of information collected during PE15-022 identified a total of 62 ball joint separation incidents, including 34 identified in ODI complaints and 31 identified in Mazda complaints and field reports (3 of the Mazda records involve vehicles/incidents that were also reported to ODI).When Mazda's design change was implemented, most of the field experience related to lower ball joints involved complaints of noise and premature wear-out.Only 1 of the ODI and 6 of the additional Mazda separation complaints identified in ODI's analysis were reported prior to January 2014.Significant increases in the number and trend in separation complaints were observed in 2015, when 30 of the ODI complaints and 16 of the additional Mazda complaints were reported.The report trend appears to be accelerating, with 29 of the reports received after ODI opened PE15-022 on June 9, 2015.There has been one crash reported to ODI related to the alleged defect (VOQ 10746510). This investigation is closed based on Mazda's recall.The 34 VOQs associated with this investigation are: 10747358, 10746510, 10744897, 10743509, 10736229, 10735938, 10734763, 10734302, 10734290, 10733813, 10732578, 10732217, 10732154, 10731850, 10730736, 10730280, 10730143, 10730114, 10726622, 10726480 10726448, 10726168, 10725839, 10725567, 10725488, 10725427, 10725390, 10717510, 10714469, 10695142, 10668978, 10648429, 10640541, 10546535Read more
PE — Closed
— Model Year: 2011
Brake Booster Failure
In March 2014, Mazda Motor Corporation (Mazda) initiated Special Service Program SSP93 to extend the warranty coverage for a specific brake booster fault condition on model year (MY) 2007-2013 Mazda CX-9 vehicles.According to Mazda's dealer communication for SSP93, the subject vehicles may exhibit a
... condition were the brake pedal is harder than usual to depress. Complainants report hearing air leakage (hissing) from the driver-side foot area during braking.The Mazda program extends the warranty coverage for repairing this condition to unlimited time and mileage for repairs performed between March 31, 2014 and March 31, 2015 and to 7 years or 90,000 miles for repairs performed after March 31, 2015.In its response to the Office of Defects Investigation's (ODI) information request letter for PE14-005, Mazda identified a problem with booster diaphragms developing tears near the outer seal/circumference that can result in noise and degraded booster performance as the tears grow in length (Figures 1-3).The tears allow leakage from the ambient to the vacuum sides of the diaphragm that reduces the differential pressure across the diaphragm and produces a hissing noise after the tears have reached 10-12 mm in length.The problem was caused by wear of the mold used for the diaphragm forming process, which resulted in increased thickness and stress in the bending area of the diaphragm.Continuous operation in environments with high ambient temperatures accelerates the hardening of the diaphragm material, further increasing the stress in the bending area and contributing to tear initiation and propagation rate.Analysis of failure data indicates that the tool wear condition affected vehicles produced after June 2010 and operated in hot states (Figures 4-6).In February 2013 the supplier introduced a new mold and changes to the diaphragm thickness monitoring process to correct the condition in production vehicles.Analysis of complaint and supplier test data indicates that the diaphragm tear condition is a progressive failure that develops slowly over time.Smaller tears have little effect on system performance.As the tear continues to grow, the effects become more evident.The hard pedal and increased effort are experienced during initial pedal application, but are diminished as the pedal is pressed further by the driver and the tear is partially sealed by the outer wall of the booster.This change from a hard to a soft pedal feel is described by some drivers as a spongy pedal.For tear lengths that were observed in warranty return parts, testing demonstrated that most booster performance can be recovered with increasing pedal apply speed and apply force.None of the tears measured in return parts grew large enough to cause a complete loss of brake booster function. The booster diaphragm tear condition results in partial reduction in booster function that progresses gradually over time with audible and pedal feel symptoms available to the driver.The condition does not result in a sudden loss of power braking assist.The effects are evident during initial pedal apply and are reduced by increased pedal apply force and rate.ODI has not identified any accidents associated with the booster diaphragm tear condition in the subject vehicles.Accordingly, this investigation is closed.The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist.The agency will continue to monitor complaints and other information relating to the alleged defect and take further action in the future if warranted.VOQs (24) associated with this investigation:10482005, 10486941, 1048793Read more
PE — Closed
— Model Year: 2008
Brake master cylinder leak
The Office of Defects Investigation (ODI) opened PE11-026 to investigate possible brake performance loss due to brake fluid leaking from the master cylinder into the brake booster in model year (MY) 2008 Mazda CX-9 vehicles.In response to ODI's information request letter, Mazda identified a problem
... with the manufacturing process for the master cylinder primary plunger that could result in inappropriate surface finish.ODI's analysis of complaints and field reports determined that the problem was isolated to several months late in the production of the MY 2008 CX-9 vehicles.Mazda indicated that changes to the plunger machining and inspection processes were incorporated late in MY 2008 vehicle production (June 25, 2008).There are no confirmed failures related to the condition in subsequent production.The subject master cylinder was used by Mazda in MY 2007 through MY 2011 CX-9 vehicles (approximately 132,000 vehicles) with no other significant problems related to master cylinder leakage.ODI's analysis identified a total of 248 complaints and field reports potentially related to the subject condition in MY 2008 CX-9 vehicles.The majority of the records reported that brake malfunction indicator lamp (MIL) illumination was the only symptom of a problem, with only 4% (9 reports) alleging any symptoms related to brake pedal feel or effectiveness.ODI identified no crash claims related to the alleged defect.In addition, analysis of this data showed a declining trend with 90 percent of the incidents reported before January 2011.Based on the extremely slow leak rate associated with the alleged defect, the declining failure trend and the low probability that the condition would affect brake performance, this investigation is closed.The ODI reports cited above can be viewed at www-odi.nhtsa.dot.gov/owners/SearchNHTSAID under the following identification numbers (ODI Nos.): 10442322, 10419837, 10449109Read more