Model year report

2011 Mazda CX-9: what breaks, and at what mileage

What breaks on the 2011 Mazda CX-9

On the 2011 Mazda CX-9, the failure owners report most often is other brake problem, and the reports cluster around 70,000 miles. The earliest to appear is master cylinder or brake booster failure, reported by a median of 60,000 miles. Overall it scores 71 out of 100, high risk for a 2011.

High risk for a 2011 — 137th riskiest of the 283 2011 vehicles we can rate. 209 owner reports; fleet size estimated from this year's own recall paperwork.

What breaks on the 2011 Mazda CX-9

Owners have reported 29 named failure modes on the 2011 Mazda CX-9, and the three most-reported carry 52% of everything filed.

Other brake problem leads with 45 reports, about 1.9 per 1,000 vehicles and with the middle half of reports between 54k to 85,000 miles.

Master cylinder or brake booster failure follows with 39 reports, usually reported between 51k to 95,000 miles.

Differential or transfer case failure follows with 24 reports, usually reported between 76k to 110,000 miles. 1 of those report mention a fire.

By system, the reports fall mostly into brakes (98), drivetrain (25) and engine (12).

At what mileage it happens

166 of the reports on the 2011 Mazda CX-9 came with an odometer reading, and half of those were filed before 75,000 miles.

Cumulatively, 21% by 50,000 miles, 70% by 100,000 miles and 98% by 150,000 miles of the dated reports had been filed.

The busiest stretch is between 70,000 and 80,000 miles, which alone holds 12% of the dated reports.

12% of the dated reports were filed below 36,000 miles.

In the order they tend to show up: master cylinder or brake booster failure around 61k, other brake problem around 71k, differential or transfer case failure around 92k and loss of braking around 95k.

Median

Other brake problem

71k
Master cylinder or brake booster failure

61k
Differential or transfer case failure

92k
Loss of braking

95k
Water pump failure

126k
Airbag inflator rupture
no odometer readings given
—
Other powertrain problem

67k
Stalling while driving

67k
Control arm, ball joint or bushing failure

125k
Other engine problem

65k
Other electrical problem

65k
Oil leak

69k

Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens

Showing the 12 most-reported failure modes of 29. The full list is in the table below.

How reports accumulate

Share of reports filed by each mileage

half by 74.5k

Every report with an odometer reading, cumulative, from 0 to 200,000 miles. A curve that climbs early is a car with early problems, whatever its total.

Line share of reports filed by that mileage
Dashed the median reported mileage

How bad it is when it goes

Across the named modes, 6 mention a crash and 5 a fire. Those are the words owners used in their own complaints, and NHTSA does not verify them, but they are the closest thing in this data to a measure of what a failure actually did.

The average severity weight across every report on this year is 5.04, where a stalled engine or a failed airbag weighs many times more than a rattling trim panel, and a figure this high means the reports are dominated by failures with safety consequences rather than annoyances. The weighting is set out in full on the methodology page.

What the top failures cost to put right, as editorial estimates for an independent US shop rather than figures from NHTSA: other brake problem at $300–$1,800, master cylinder or brake booster failure at $450–$2,200, differential or transfer case failure at $900–$4,200 and loss of braking at $400–$3,000. Dealer labour, a seized bolt or a part that is no longer made can push any of these past the top of its range.

26% of the reports on this year sit in the engine, transmission, drivetrain or cooling systems — the four where a repair bill is usually four figures.

Every reported failure mode

Mileage figures are percentiles of owner-reported readings. Click a column to sort.
Failure mode	System	Reports	With reading	25th	Median	75th	Per 1,000	Typical repair	Severity
Other brake problem	brakes	45	42	54k	71k	85k	1.9	$300–$1,800	High
Master cylinder or brake booster failure	brakes	39	36	51k	61k	95k	1.6	$450–$2,200	Critical
Differential or transfer case failure	drivetrain	24	19	76k	92k	112k	1.0	$900–$4,200	High
Loss of braking	brakes	13	12	50k	95k	121k	0.5	$400–$3,000	Critical
Water pump failure	cooling	9	7	—	126k	—	0.4	$500–$2,200	High
Airbag inflator rupture	airbag	9	0	—	—	—	0.4	$0–$0	Critical
Other powertrain problem	transmission	7	7	—	67k	—	0.3	$400–$4,500	High
Stalling while driving	engine	5	3	—	67k	—	0.2	$300–$2,500	Critical
Control arm, ball joint or bushing failure	suspension	4	2	—	125k	—	0.2	$400–$2,200	High
Other engine problem	engine	4	3	—	65k	—	0.2	$300–$4,000	High
Other electrical problem	electrical	4	3	—	65k	—	0.2	$250–$2,000	Moderate
Oil leak	engine	3	3	—	69k	—	0.1	$250–$2,200	Moderate
Control module (ECM/PCM/BCM) failure	electrical	3	3	—	110k	—	0.1	$700–$3,000	High
Blower motor or climate control failure	hvac	3	3	—	102k	—	0.1	$250–$1,200	Moderate
Headlight failure or clouding	lighting	3	1	—	130k	—	0.1	$150–$1,800	Moderate
Other suspension problem	suspension	3	0	—	—	—	0.1	$350–$2,000	Moderate
Other driver assistance problem	adas	3	2	—	50k	—	0.1	$250–$1,800	High
Other steering problem	steering	2	2	—	64k	—	0.1	$350–$2,400	High
Other wheel or tire problem	wheels	2	2	—	67k	—	0.1	$200–$1,500	High
Complete transmission failure	transmission	1	1	—	118k	—	0.0	$2,800–$8,000	Critical
Torque converter failure	transmission	1	1	—	64k	—	0.0	$1,100–$3,200	High
CV axle or driveshaft failure	drivetrain	1	0	—	—	—	0.0	$450–$2,200	High
Audio or connectivity failure	infotainment	1	1	—	91k	—	0.0	$150–$900	Low
Premature brake pad or rotor wear	brakes	1	1	—	63k	—	0.0	$300–$1,400	Moderate
Airbag warning light or occupant sensor fault	airbag	1	1	—	158k	—	0.0	$300–$1,600	High
Seat belt or retractor failure	airbag	1	1	—	9k	—	0.0	$200–$900	High
Door latch or handle failure	body	1	0	—	—	—	0.0	$250–$1,200	High
Other speed control problem	adas	1	1	—	173k	—	0.0	$250–$2,000	Critical
Other body or interior problem	body	1	1	—	11k	—	0.0	$200–$2,000	Moderate
Unclassified problem	other	14	8	30k	95k	105k	0.6	—	Moderate

Rate per 1,000 uses a fleet-size estimate derived from recall paperwork for this exact model year. It is a lower bound. Repair costs are typical independent-shop ranges for the failure, not figures from these reports.

How often, against how many were built

Scaled by an estimate of how many of these cars exist, the 2011 Mazda CX-9 draws about 8.6 per 1,000 vehicles, which puts it in the 91st percentile of complaint rates among 2011 vehicles we can rate.

That denominator is the weakest number on the page and it is fair to say so plainly. Rate per 1,000 uses a fleet-size estimate derived from recall paperwork for this exact model year. It is a lower bound.

The working figure is 24,185 vehicles. If the true number is twice that, every rate on this page is half what it says; the ranking against other 2011 vehicles, which is what the risk score uses, is far more robust than the rate itself.

What owners wrote

Verbatim from NHTSA complaint narratives, trimmed for length. The odometer reading is the one the owner gave.

Master cylinder or brake booster failure

I had my cx-9 gt driving on the road. This happened while I drove on street and stepped on brake the pedal to stop for a red light. I almost hit the car in front of me, because my brake at this time, all of sudden, took longer stopping distance as I expected. It was a close call to hit the car in front of me while my braking system reacted differently. After almost hitting the car, I drove very cautiously in a fear that I might lose the control of my brakes totally; the bad feeling for the unpredictable braking system really put my family's safety in a compromise. I have only had this car for one and half year and drove around 24,000 miles. This never happened to the three cars I have drove in my 20 years of driving history. The braking system should be designed and provide what it should perform without any compromise. But this one didn't do the job it should. Don't even see any warning light in the dash. Today, I took my car to the mazda service. They responded that one of the components of the braking system is defective. They mentioned that the "brake booster" is broken. I am so surprised at how these instrumental systems…

24,000 miles NHTSA complaint 951128 filed 2012-11-27

Similar to other complaints here, I recently started noticing hissing when I pressed my brakes....... I noticed that I was having a hard time coming to a complete stop. I took my cx9 in today august 14, 2013 to gunther mazda in fort lauderdale. I thought it was going to be a simple change of brake pads, little did I know I was in for $700!!!!!- apparently this is nothing new for mazda, there was an investigation going on by the NHTSA for the 2008 cx9 model and guess what? The 2011 seems to be having the same exact issue. The mechanic said the pads are fine but the master cylinder and booster need to be replaced. I'm going to call mazda usa to see what they can do but unless everyone starts demanding answers they're going to be laughing all the way to the bank. It'll take a strong effort to make them issue a recall. This is my last mazda. I'm going back to my lexus, more expensive by a lot but I didn't have to worry about putting my life and my daughter's life at risk. This is ridiculous. *tr

57,000 miles NHTSA complaint 1001878 filed 2013-08-14

Differential or transfer case failure

Tl* the contact owns a 2011 mazda cx-9. The contact stated that there were fuel fumes inside the cabin of the vehicle. Additionally, the contact was driving 20 MPH when the vehicle began to decelerate independently and stalled. The vehicle was taken to the dealer, who determined that the transfer case was cracked and seized. The failure was not reported to the manufacturer. The VIN was not available. The failure and current mileage was 36,300. Updated 07/30/13*lj the dealer replaced the transfer case. Updated 08/01/13

36,300 miles NHTSA complaint 985176 filed 2013-06-10

Tl* the contact owns a 2011 mazda cx-9. The contact stated that there were fuel fumes inside the cabin of the vehicle. Additionally, the contact was driving 20 MPH when the vehicle began to decelerate independently and stalled. The vehicle was taken to the dealer, who determined that the transfer case was cracked and seized. The failure was not reported to the manufacturer. The VIN was not available. The failure and current mileage was 36,300. Updated 07/30/13*lj the dealer replaced the transfer case. Updated 08/01/13

36,300 miles NHTSA complaint 985177 filed 2013-06-10

Recalls on the 2011 model year

NHTSA has issued 4 recall campaigns covering the 2011 Mazda CX-9, affecting an estimated 56,306 vehicles. A recall is a different kind of evidence from a complaint: it is the regulator and the manufacturer agreeing that something has to be fixed, and the fix is free for as long as the car exists.

The campaigns cover air bags:frontal:passenger side:inflator module and suspension:front:control arm:lower arm. Whether the work was actually done on the car in front of you is a question only the VIN can answer, and the manufacturer or NHTSA will answer it free.

Recalls also distort complaint counts. Publicity about a campaign reminds owners that complaining is possible, so reports for a recalled component often spike after the recall rather than before it.

19V782000

AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE

69,879 vehicles 2019-10-31

Defect: 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.
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants resulting in serious injury or death.
Remedy: 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.

18V717000

AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE

155,436 vehicles 2018-10-12

Defect: 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…
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants resulting in serious injury or death.
Remedy: 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.

17V429000

AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE

205,377 vehicles 2017-06-29

Defect: 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.
Consequence: An inflator rupture may result in metal fragments striking the vehicle occupants resulting in serious injury or death.
Remedy: 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.

15V451000

SUSPENSION:FRONT:CONTROL ARM:LOWER ARM

193,484 vehicles 2015-07-20

Defect: 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.
Consequence: Over time, the ball joint corrosion may result in the front lower control arm separating from the ball joint, causing a loss of steering control and increasing the risk of a crash.
Remedy: 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…

Recall work is free at a franchised dealer regardless of the car's age. Check the VIN at nhtsa.gov/recalls before assuming it was done.

How it ranks in the 2011 field

The score at the top of the page, placed among its peers. The zones are the same thresholds the scorer applies, read out of the scorer itself, so the picture and the band word cannot disagree.

Risk score against the rest of the 2011 field

Scores are ranked within the model year, never across years, because an older car has had longer to accumulate reports.

Left fewer and less serious reports
Right more, or worse
Marker this vehicle

Where 2011 sits in the model line

High risk for a 2011 — 137th riskiest of the 283 2011 vehicles we can rate. The comparison is always within the same model year, so an older car is never penalised for having had longer to break.

Across the 16 model years of this car that carry enough reports to score, 2007 comes out best at 64 and 2018 worst at 82, with 2011 itself at 71.

If the model year is negotiable, 2007 and 2023 score lower than 2011 by a margin worth acting on. Same body, same engines, different luck — usually a supplier change or a mid-cycle fix, which the complaint data can show but never explain.

Within the 2007–2015 generation specifically, 2007 is the strongest year at 64 and 2010 the weakest at 74.

Scores compare each year against other cars of the same model year, so a low number on an older car is a real result and not an artefact of age.

Risk score by model year, out of 100

Shorter is better. Years with too few reports to score are shown without a bar rather than as a zero, because no data is not good news.

Within the 2007-2015 generation, 2007 Mazda CX-9 scores best at 64 and 2010 Mazda CX-9 worst at 74.

Where to spend the inspection money

The mileages below are where the first quarter of reports for each mode had already been filed, which makes them the point at which a fault is worth looking for rather than the point at which it happens: loss of braking from about 50k, master cylinder or brake booster failure from about 51k, other brake problem from about 54k and differential or transfer case failure from about 76k.

On a 2011 Mazda CX-9 with more miles than that on it, the useful question to put to a seller or a mechanic is whether loss of braking has been dealt with, and if so with what parts and at whose expense. A car that has already had the repair is in a different position from one that has not.

None of this is a diagnosis. It is a list of what other owners of the same model year reported, ordered by when they reported it, which is a good place to point an inspection and a poor place to stop.

Where these figures stop being useful

209 owner reports; fleet size estimated from this year's own recall paperwork. Every count on this page is therefore a floor: it is the number of owners who went to the trouble of filing with a federal agency, which is a small and self-selected fraction of the owners who had the fault.

Of those 209 reports, 166 carried an odometer reading, so the mileages here describe 79% of the sample rather than all of it. Owners also round: readings pile up on multiples of ten thousand, which is why this site publishes "about 90,000 miles" and not "91,438".

Named failure modes come from matching phrases in the complaint text, so a badly worded complaint can land in the wrong bucket. The effect washes out across hundreds of reports and does not wash out across five.

And nothing here predicts what one car will do. These are other people's complaints, filed years apart, on cars maintained by strangers. Read the page as a map of where this model year has previously gone wrong, then have the specific car in front of you inspected.

Questions this page answers

What are the most common problems with the 2011 Mazda CX-9?

The most-reported failures are other brake problem (45 reports, median 70,000 miles), master cylinder or brake booster failure (39 reports, median 60,000 miles) and differential or transfer case failure (24 reports, median 90,000 miles). Counts come from owner complaints filed with NHTSA, which are voluntary, so they show what owners bothered to report rather than every fault that occurred.

At what mileage do 2011 Mazda CX-9 problems start?

Master cylinder or brake booster failure is the earliest failure mode to show up, with a median reported mileage of 60,000 miles and a quarter of reports before 50,000 miles. Across all failure modes on this year, the median report sits at 75,000 miles.

Is the 2011 Mazda CX-9 reliable?

It scores 71 out of 100 on our risk index, which is high — 137th riskiest of the 283 2011 vehicles we can rate. The score is a comparison against other 2011 vehicles, not a prediction about any individual car, and it is built from complaint rates, severity and how early failures appear.

Which year of the Mazda CX-9 is best?

Within the 2007–2015 generation, 2007 scores best at 64 out of 100 and 2010 worst at 74. Same body, same engines, different luck.

Where this comes from. Every figure above is computed from NHTSA owner complaints and recall records for this exact make, model and year. Complaints are voluntary and self-selected, so treat counts as a floor. The methodology page writes out each formula, and the same numbers are available as JSON.

What breaks at my mileage Compare with another car

Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt 30 August 2026 Published by AtWhatMileage How every figure is computed