The vehicle dossier US · 2011

2011 Mazda
CX-9Problems & recalls

170 distinct owner reports in the NHTSA snapshot. Brakes appears in 99 of them. Explore what was reported—and which official actions are on file.

Snapshot Sep 28, 2026Live NHTSA complaint API How this dossier is compiled

01 / Owner-reported evidence

What owners reported.

Categories attached to 170 distinct reports. A report can mention more than one component, so category totals can overlap.

Brakes99 reports
Transmission & drivetrain25 reports
Other components23 reports
Air bags22 reports
Engine15 reports
Suspension8 reports
Electrical system5 reports
Steering4 reports
Fuel system1 reports
Visibility1 reports
Body & structure1 reports
See original component labels
SERVICE BRAKES97
POWER TRAIN25
AIR BAGS22
ENGINE15
SUSPENSION6
ELECTRICAL SYSTEM5
UNKNOWN OR OTHER5
ELECTRONIC STABILITY CONTROL (ESC)4
STEERING4
VEHICLE SPEED CONTROL4
WHEELS3
EXTERIOR LIGHTING3
SERVICE BRAKES, HYDRAULIC2
SEAT BELTS2
TRACTION CONTROL SYSTEM1
POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE)1
SEATS1
EQUIPMENT:ELECTRICAL:ANTI-THEFT DEVICES1
SERVICE BRAKES, HYDRAULIC:POWER ASSIST:VACUUM1
TIRES1
SUSPENSION:FRONT:CONTROL ARM:LOWER ARM1
FUEL SYSTEM, GASOLINE1
VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM:FAN/MOTOR1
VISIBILITY:SUN/MOON ROOF ASSEMBLY1
STRUCTURE1
SUSPENSION:FRONT:CONTROL ARM1

These are reports made to NHTSA, not verified diagnoses. More reports can reflect more vehicles, more time on the road, or greater reporting activity.

The reporting timeline

When reports arrived.

Reports by year filed, not by the year a problem occurred. Showing the latest 15 years with reports.

Year filed (last two digits)Latest report: Jun 30, 2026
Mileage, where supplied

74,000 miles is the median among 137 reports with usable mileage. The middle half spans 53,500–103,000 miles.

This describes the submitted reports. It does not predict when a vehicle will fail.

02 / Official safety campaigns

4 recall campaigns on file.

A campaign can cover only certain production dates or configurations. The count does not tell you whether an individual car has an open recall.

Oct 31, 2019 Safety recallAIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULECampaign 19V782000

A do-not-drive advisory is recorded. Verify applicability immediately with NHTSA or the manufacturer.

Reported concern

Mazda North American Operations (Mazda) is recalling certain 2007-2012 CX-7, CX-9, and 2009-2012 Maza6 vehicles. These vehicles had their passenger frontal air bag inflators previously replaced under a prior recall using inflators of the same design. The inflators may explode due to propellant degradation occurring after long-term exposure to high absolute humidity, temperature and temperature cycling.

Manufacturer’s stated response

Owners are advised not to drive their vehicles until the repair has been performed. Mazda will notify owners, and dealers will replace the front passenger air bag inflator with an alternate one, free of charge. The recall began December 3, 2019. Owners may contact Mazda customer service at 1-800-222-5500, option 4. Mazda's number for this recall is 1317F. Note: This recall supersedes recalls 16V356 and 17V012.

Manufacturer campaign: 1317F

Read campaign 19V782000 at NHTSA
Oct 12, 2018 Safety recallAIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULECampaign 18V717000

A do-not-drive advisory is recorded. Verify applicability immediately with NHTSA or the manufacturer.

Reported concern

Mazda North American Operations (Mazda) is recalling certain 2014-2015 Mazda CX-9 vehicles sold, or ever registered in the states of Alabama, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, South Carolina, Texas, Puerto Rico, American Samoa, Guam, the Northern Mariana Islands (Saipan), and the U.S. Virgin Islands or "Zone A." Additionally, unless covered in "Zone A," Mazda is recalling certain 2011-2013 Mazda6, 2011-2012 CX-7, and 2011-2015 CX-9 sold, or ever registered in the states of Arizona, Arkansas, Delaware, Illinois, Indiana, Kansas, Kentucky, Maryland, Missouri, Nebraska, Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia, or "Zone B." Additionally, unless covered in Zone A or Zone B, Mazda is recalling certain 2010-2013 Mazda6, 2010-2012 CX-7, and 2010-2015 CX-9 vehicles ever registered in the states of Alaska, Colorado, Connecticut, Idaho, Iowa, Maine, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, New York, North Dakota, Oregon, Rhode Island, South Dakota, Utah, Vermont, Washington, Wisconsin, and Wyoming or "Zone C." These vehicles are equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the passenger frontal air bag, these inflators may explode due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.

Manufacturer’s stated response

Mazda will notify owners, and dealers will replace the front passenger air bag inflator with an alternate inflator, free of charge. The recall began November 9, 2018. Owners may contact Mazda customer service at 1-800-222-5500, Option 4. Mazda's number for this recall is 1317F.

Manufacturer campaign: 1317F

Read campaign 18V717000 at NHTSA
Jun 29, 2017 Safety recallAIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULECampaign 17V429000

A do-not-drive advisory is recorded. Verify applicability immediately with NHTSA or the manufacturer.

Reported concern

Mazda North America Operations (Mazda) is recalling certain 2009-2011 Mazda6, and 2007-2011 CX-7 and CX-9 vehicles. These vehicles are equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules, and used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the front air bags, these inflators may rupture due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.

Manufacturer’s stated response

Owners are advised not to drive their vehicles until the remedy is performed. Mazda will notify owners, and dealers will replace the passenger frontal air bag inflator with an alternate inflator, free of charge. The recall began on August 30, 2017. Owners may contact Mazda customer service at 1-800-222-5500. Mazda's number for this recall is 1317F. Note: This recall supersedes recall 16V356 and all vehicles that were not remedied under that campaign are now covered by this one.

Manufacturer campaign: 1317F

Read campaign 17V429000 at NHTSA
Jul 20, 2015 Safety recallSUSPENSION:FRONT:CONTROL ARM:LOWER BALL JOINTCampaign 15V451000

Reported concern

Mazda North American Operations (Mazda) is recalling certain model year 2007-2014 CX-9 vehicles manufactured October 24, 2006, to December 28, 2013. The affected vehicles have front suspension ball joints that may corrode from water leaking into the fitting.

Manufacturer’s stated response

Mazda will notify owners, and dealers will replace both the left and right lower control arms, free of charge. The recall began on September 14, 2015. The recall will begin with model year 2007-2009 vehicles registered in Connecticut, Delaware, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, Virginia, Washington D.C., West Virginia, and Wisconsin. The second phase will be for model year 2010-2014 vehicles in the same states. Finally, all remaining vehicles will be remedied. Owners may contact Mazda customer service at 1-800-222-5500. Mazda's number for this recall is 8515G.

Manufacturer campaign: 8515G

Read campaign 15V451000 at NHTSA
Check this car’s VIN at NHTSA

03 / The manufacturer’s record

Instructions. Updates. Responses.

295 distinct communications list this model-year. Showing the latest 12. A matching model-year does not establish that every engine, trim or reported symptom is covered.

Aug 20, 2026 Service Bulletin/Repair InstructionsSA-055-26Product Quality Information (PQI) DESCRIPTION Service Information MT-041/12 is no longer valid. It has been unpublished and superseded by the Field Quality Information Report (FQIR) reporting system.NHTSA ID 11037013

Product Quality Information (PQI) DESCRIPTION Service Information MT-041/12 is no longer valid. It has been unpublished and superseded by the Field Quality Information Report (FQIR) reporting system.

Components: UNKNOWN OR OTHER. Confirm detailed applicability in the original document.

Source record 11037013 at NHTSA
Jun 19, 2026 Service Bulletin/Repair InstructionsSA-041-26This 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...), i…NHTSA ID 11034447

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.

Components: ELECTRICAL SYSTEM · ENGINE. Confirm detailed applicability in the original document.

Source record 11034447 at NHTSA
Apr 21, 2026 Service Bulletin/Repair InstructionsSA-029-26This 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 s…NHTSA ID 11032103

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.).

Components: ENGINE · POWER TRAIN · SERVICE BRAKES · UNKNOWN OR OTHER. Confirm detailed applicability in the original document.

Source record 11032103 at NHTSA
Dec 17, 2025 Service Bulletin/Repair InstructionsSA-061-25If 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 installe…NHTSA ID 11026917

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.

Components: ELECTRICAL SYSTEM. Confirm detailed applicability in the original document.

Source record 11026917 at NHTSA
Dec 10, 2025 Service Bulletin/Repair Instructions07-004-25aA musty/mildew type odor may come from the vents when the air conditioning (A/C) system is operating. It is most noticeable when the A/C is first turned ON. This odor is the result of mold growth in the A/C evaporator/cooling u…NHTSA ID 11026904

A musty/mildew type odor may come from the vents when the air conditioning (A/C) system is operating. It is most noticeable when the A/C is first turned ON. This odor is the result of mold growth in the A/C evaporator/cooling unit which is caused by condensation, dust, and pollen within the cooling unit. This condition is usually worse during high humidity conditions. “Mazda Air Cooling Coil Coating” is available to encapsulate the mold to reduce odors. If the product is properly applied, it can effectively reduce the musty/mildew odor for up to three years. NOTE: See parts information for Mazda Air Cooling Coil Coating and Kit part numbers.

Components: UNKNOWN OR OTHER. Confirm detailed applicability in the original document.

Source record 11026904 at NHTSA
Aug 22, 2025 Service Bulletin/Repair InstructionsSA-039/25Some vehicles may experience exterior trim heat damage such (melted, separating, etc.) when parked near a glass building or Low-E windows. This may be caused by the sun's reflection. If a structure's windows create enough of a …NHTSA ID 11022742

Some vehicles may experience exterior trim heat damage such (melted, separating, etc.) when parked near a glass building or Low-E windows. This may be caused by the sun's reflection. If a structure's windows create enough of a curve, the concave glass can focus the sun's rays onto a small area and acting like magnifiying glass direct the sunbeams into a hot pinpoint of light. This magnifcation of the sun's rays can cause damage to vehicle trim (see examples). Additional information and exemplar images regarding this phenomenon can be found by performing a google search.

Components: STRUCTURE:BODY · UNKNOWN OR OTHER. Confirm detailed applicability in the original document.

Source record 11022742 at NHTSA
Aug 14, 2025 Service Bulletin/Repair InstructionsSA-036-25When replacing the SiriusXM satellite radio unit, a call must be made to inform SiriusXM of the existing Radio ID and the new/replacement SAT Radio ID as soon as possible to ensure the customer leaves the dealership with an act…NHTSA ID 11022727

When replacing the SiriusXM satellite radio unit, a call must be made to inform SiriusXM of the existing Radio ID and the new/replacement SAT Radio ID as soon as possible to ensure the customer leaves the dealership with an active SAT radio.

Components: UNKNOWN OR OTHER. Confirm detailed applicability in the original document.

Source record 11022727 at NHTSA
Jun 19, 2025 Service Bulletin/Repair InstructionsSA-032-25Some customers may complain about a noisy HVAC blower motor or odor after a cabin air filter replacement. Foreign debris on the blower motor after servicing the cabin air filter may be the cause. During the removal of the cabin…NHTSA ID 11020039

Some customers may complain about a noisy HVAC blower motor or odor after a cabin air filter replacement. Foreign debris on the blower motor after servicing the cabin air filter may be the cause. During the removal of the cabin air filter, foreign debris (leaves, dust, dirt....ect.) may fall on the blower motor causing a fluttering type noise or odor.

Components: UNKNOWN OR OTHER. Confirm detailed applicability in the original document.

Source record 11020039 at NHTSA
May 22, 2025 Service Bulletin/Repair Instructions09-024-25Some vehicles may exhibit following symptoms: 1. The rearview mirror (1) rattles up and down (2) while adjusting the mirror. 2. The rearview mirror (1) makes a rattle noise depending on the road surface conditions while driving…NHTSA ID 11019097

Some vehicles may exhibit following symptoms: 1. The rearview mirror (1) rattles up and down (2) while adjusting the mirror. 2. The rearview mirror (1) makes a rattle noise depending on the road surface conditions while driving. This concern is caused during rearview mirror installation. The adhesive is squeezed out between the windshield and the mirror base. The rearview mirror is assembled on top of the overextended adhesive. The adhesive is softened by heat, and loosening screws, results in a rattling concern.

Components: UNKNOWN OR OTHER. Confirm detailed applicability in the original document.

Source record 11019097 at NHTSA
Apr 25, 2025 Service Bulletin/Repair Instructions07-004-25A musty/mildew type odor may come from the vents when the air conditioning (A/C) system is operating. It is most noticeable when the A/C is first turned ON. This odor is the result of mold growth in the A/C evaporator/cooling u…NHTSA ID 11017699

A musty/mildew type odor may come from the vents when the air conditioning (A/C) system is operating. It is most noticeable when the A/C is first turned ON. This odor is the result of mold growth in the A/C evaporator/cooling unit which is caused by condensation, dust, and pollen within the cooling unit. This condition is usually worse during high humidity conditions. “Mazda Air Cooling Coil Coating” is available to encapsulate the mold to reduce odors. If the product is properly applied, it can effectively reduce the musty/mildew odor for up to three years.

Components: UNKNOWN OR OTHER. Confirm detailed applicability in the original document.

Source record 11017699 at NHTSA
Aug 15, 2024 Service Bulletin/Repair InstructionsSA-058-24Some vehicles may experience exterior trim heat damage such (melted, separating, etc.) when parked near a glass building or Low-E windows. This may be caused by the sun's reflection.NHTSA ID 11007022

Some vehicles may experience exterior trim heat damage such (melted, separating, etc.) when parked near a glass building or Low-E windows. This may be caused by the sun's reflection.

Components: STRUCTURE:BODY. Confirm detailed applicability in the original document.

Source record 11007022 at NHTSA
Aug 15, 2024 Service Bulletin/Repair InstructionsSA-057-24If 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 installe…NHTSA ID 11007019

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.

Components: ELECTRICAL SYSTEM · ENGINE · UNKNOWN OR OTHER. Confirm detailed applicability in the original document.

Source record 11007019 at NHTSA
Browse all manufacturer records by page

Records below contain the NHTSA bulk summary unless a document-reviewed explainer is linked. A service bulletin is not a safety recall or a promise of a free repair. Records may be revised or superseded; verify the current document with the manufacturer.

04 / Agency investigations

Official inquiries.

An investigation is an inquiry into a potential concern. Its presence does not establish a defect, and a closed case does not certify a car’s condition.

Opened May 2, 2019 ClosedInadvertent Curtain Air Bag DeploymentPE19006

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 through 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.

Recorded closure: Jan 15, 2021

Find investigation PE19006
Opened Jun 9, 2015 ClosedLower ball joint separationPE15022

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 water 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, 10546535

Recorded closure: Aug 20, 2015

Campaign reference in the source: 15V451000

Find investigation PE15022
Opened Feb 10, 2014 ClosedBrake Booster FailurePE14005

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, 1048793

Recorded closure: Jun 26, 2014

Find investigation PE14005

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