Mazda CX-9 Investigations

4 ODI actions on file.

• PEPE19006CLOSEDOpened 5/2/2019
  Inadvertent Curtain Air Bag Deployment
  AIR BAGS

  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.

• PEPE15022RECALLOpened 6/9/2015
  Lower ball joint separation
  SUSPENSION:FRONT:CONTROL ARM:LOWER BALL JOINT

  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

• PEPE14005CLOSEDOpened 2/10/2014
  Brake Booster Failure
  SERVICE BRAKES, HYDRAULIC:POWER ASSIST

  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

• PEPE11026CLOSEDOpened 8/9/2011
  Brake master cylinder leak
  SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS:MASTER CYLINDER

  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, 10449109