Every safety complaint, recall and defect investigation the US government
holds on this vehicle.
Owners have filed 13 safety complaints
about the 2010 Mercury Mountaineer with the US government. Of those, no death is recorded. One recall campaign is open against it, covering the seats.
The most complained-about system is the brakes,
named in 5 complaints, 38% of the total.
The typical failure was reported at 38,660 miles,
the median across the 11
complaints that gave
an odometer reading.
Compiled from NHTSA's complaint, recall and investigation files
· Covers May 2012 to June 2022 · How this is counted
What is on file
13 complaints on file
13
Complaints
0
Describe a crash
0
Mention fire
0
People injured
0
Deaths
A complaint is an unverified account by the person who filed it, not a
finding of fault. One complaint is one ODI number, which is how NHTSA counts
them.
A recall is the manufacturer conceding a defect, and the repair is free.
Whether one covers your particular car is a question only its VIN can
answer, because a campaign covers a production range rather than a
model year.
Which system owners named
Complaints naming each system
SERVICE BRAKES 5 · 38%
5 38%
VEHICLE SPEED CONTROL 4 · 31%
4 31%
ENGINE 3 · 23%
3 23%
POWER TRAIN 2 · 15%
2 15%
STEERING 2 · 15%
2 15%
ELECTRICAL SYSTEM 1 · 8%
1 8%
FUEL SYSTEM, GASOLINE 1 · 8%
1 8%
FUEL/PROPULSION SYSTEM 1 · 8%
1 8%
INTERIOR LIGHTING 1 · 8%
1 8%
SEAT BELTS 1 · 8%
1 8%
SEATS 1 · 8%
1 8%
STRUCTURE 1 · 8%
1 8%
048
Red marks a system with a recall campaign against it.
One complaint can name several systems, so these add up to more than 13.
When the complaints arrived
By the year NHTSA received them
By the year NHTSA received them, which is not the year the failures
happened. They peaked in 2013 at 3.
4 3 2 1
122012132013142014152015162016182018192019222022
This is the year the complaint was filed, not the year the failure
happened. The range runs from 2012 to 2022.
Crash test ratings
NHTSA New Car Assessment Program
NHTSA crashes a car into a barrier and a pole and measures what
happens to the dummies inside. This is what it awarded the 2010 Mercury MOUNTAINEER, and it is a separate
question from what owners report going wrong later.
Test
4-DR. w/SAB
Overall
Not rated
Frontal crash
Not rated
Frontal, driver
Frontal, passenger
Side crash
Not rated
Side barrier
Not rated
Side pole
Not rated
Rollover
Chance of rollover
22.8%
Stability control standard Forward collision warning standard Lane departure warning standard
NHTSA made its frontal crash test harder for the 2011 model year, and says ratings from before that change should not be compared with ratings after it.
A dash means NHTSA did not rate that test for this vehicle.
Recall campaigns
1 on file
SEATS:FRONT ASSEMBLY:RECLINER
10V161000 · April 20, 2010
The defect
FORD IS RECALLING CERTAIN MODEL YEAR 2010 FUSION, EXPLORER, EXPLORER SPORT TRAC, AND MERCURY MILAN AND MOUNTAINEER VEHICLES MANUFACTURED BETWEEN DECEMBER 15, 2009 THROUGH FEBRUARY 3, 2010 EQUIPPED WITH FRONT SEAT MANUAL RECLINERS. THESE VEHICLES FAIL TO COMPLY WITH THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 202, "HEAD RESTRAINT." THE RECLINER GEAR PLATE TEETH MAY BE OUT OF DIMENSION SPECIFICATION WHICH COULD RESULT IN LIMITED PAWL TO GEAR PLATE TOOTH ENGAGEMENT.
The risk
IN THE EVENT OF A CRASH, THE SEATBACK AND HEAD RESTRAINT MAY MOVE REARWARD, INCREASING THE RISK OF INJURY.
The remedy
DEALERS WILL REPLACE THE MANUAL RECLINERS FOR BOTH POWER AND MANUAL SEATS FREE OF CHARGE. THE SAFETY RECALL IS EXPECTED TO BEGIN ON OR BEFORE APRIL 30, 2010. OWNERS MAY CONTACT FORD AT 1-866-436-7332.
FORD MOTOR COMPANY · up to 33,256 vehicles across all model years covered
Defect investigations
1 on file
An investigation means NHTSA has decided a pattern is worth examining. A
preliminary evaluation is often closed with no action; an engineering
analysis is the stage that usually precedes a recall.
Fleet Vehicle Recall Completion Audit
AQ10001
Closed audit query · opened November 18, 2010 · closed December 28, 2015
unknown or other
On November 18, 2010, NHTSA's Recall Management Division (RMD) opened an audit query (AQ10-001) to investigate recall remedy completion by rental car companies on safety recall campaigns.It was expected to provide the agency an indication of how completely and how quickly rental car fleets perform necessary recall-related remedies on the vehicles owned and then rented/leased for use on the roadways.RMD queried three (3) major motor vehicle manufacturers (Ford, Chrysler, and General Motors) and requested data regarding completion figures for fifteen (15) discreet safety recalls.Analysis of this data demonstrated that rental car recalls completion was neither complete nor consistent.The rental car companies representing the largest market share in the industry were then queried as to their respective policies for the rental, lease, and sale of vehicles with open recalls.The data and responses from the manufacturers and the rental car companies can be found in the document repository by accessing the ?Associated Documents link above.In December 2015, Congress enacted the Fixing America's Surface Transportation (FAST) Act.One section of the Act prohibits rental car companies from renting, leasing, or selling motor vehicles subject to open safety recalls.With the passage of the FAST Act and its prohibition, there is no continuing need for the agency to investigate rental car recall completions.Accordingly, this investigation is closed.The agency reserves the right to open any future investigations, including audits of individual recalls, or groups of recalls, or rental car companies, to examine more closely safety recalls performance and completion issues in this area.
In owners’ own words
Quoted from the complaint file
Quoted from NHTSA's complaint file. These are unverified accounts by the
people who filed them, not findings of fault.
ELECTRICAL SYSTEM
109,000 miles
The contact owns a 2010 Mercury Mountaineer. The contact stated that the check engine warning light was illuminated. The vehicle was taken to an independent mechanic to be diagnosed. The contact was informed that the computer had provided an incorrect error code. The vehicle was also diagnosed by an authorized Ford tech who confirmed the failure with the computer. The manufacturer was contacted and informed of the failure. The manufacturer referred the contact to the NHTSA to file a complaint. The vehicle was not repaired. The approximate failure mileage was 109,000.
NHTSA complaint 11468066. Filed by an owner and not verified by NHTSA or by us.
SERVICE BRAKES
TL* THE CONTACT OWNS A 2010 MERCURY MOUNTAINEER. WHILE THE CONTACT'S WIFE WAS DRIVING 70 MPH, SHE DEPRESSED THE BRAKE PEDAL AND THE FRONT DRIVER'S SEAT STARTED TO SLIDE BACKWARDS AND THE INTERIOR LIGHTING ILLUMINATED. THERE WERE NO WARNING INDICATORS ILLUMINATED. THE DRIVER LOST CONTROL OF THE VEHICLE AS IT MADE A 360 DEGREE SPIN. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE DEALER WAS NOT CONTACTED. THE MANUFACTURER WAS INFORMED OF THE FAILURE. THE FAILURE MILEAGE WAS UNKNOWN.
NHTSA complaint 11292295. Filed by an owner and not verified by NHTSA or by us.
UNKNOWN OR OTHER
90,500 miles
DOORS LOCKING MECHANISM MALFUNCTIONING AND CODING NUMBERS NOT FUNCTIONING. BEING LOCKED OUT WHEN USING CODE #S. CHAIN CRANKIN HARSHLY BUT NOT UNLOCKING DOORS. WHEN USING KEY INSTEAD OF CODE KEY DOES NOT UNLOCK NOR LOCK ANY DOORS EXCEPT DRIVERS DOOR LOCK.
NHTSA complaint 11287792. Filed by an owner and not verified by NHTSA or by us.
POWER TRAIN
REAR DIFFERENTIAL IS FILLING WITH WATER PASS THE FILL PLUG. THIS IS A GARAGE KEPT CAR AND NEVER OFF ROAD NOR DIRVEN IN DEEP WATER. FIRST TIME DISCOVERED AT 22000 MILES AND THE DEALER REPLACE THE PINION SEAL AND OIL, BUT COULD NOT FIND THE CAUSE. DIFFERENTIAL NOW MAKING NOISE AND AGAIN FULL OF WATER PAST THE FILL PLUG. SEARCHED ONLINE AND FOUND SEVERAL PEOPLE WITH THE SAME PROBLEM WITH FORD PRODUCTS. DEALER CANNOT FIND OR NOT WILLING TO FIND THE CAUSE. CALLED FORD AND THEY OFFER LITTLE TO NO SUPPORT. GUESS THEY ARE WAITING FOR THE DIFFERENTIALS TO LOCK UP AT HIGHWAY SPEED AND KILL A DOZEN OF SO PEOPLE.
NHTSA complaint 11157272. Filed by an owner and not verified by NHTSA or by us.
ENGINE
65,000 miles
AT HIGH SPEEDS, THE CAR STALLS. IT ALSO STALLS AT STOP LIGHTS. THIS HAPPENS REPEATEDLY, AND FORD CANNOT FIGURE OUT WHAT IS WRONG WITH IT.
NHTSA complaint 10876658. Filed by an owner and not verified by NHTSA or by us.
SEAT BELTS
60,000 miles
TL* THE CONTACT OWNS A 2010 MERCURY MOUNTAINEER. THE CONTACT STATED THAT WHILE ATTEMPTING TO LATCH BOTH OF THE SECOND ROW SEAT BELTS, THE BELTS FRACTURED AND DETACHED FROM THE VEHICLE. THE VEHICLE WAS TAKEN TO THE DEALER. THE TECHNICIAN WAS UNABLE TO DETERMINE THE CAUSE OF THE FAILURE. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS 60,000.
NHTSA complaint 10778536. Filed by an owner and not verified by NHTSA or by us.
If this is your car and a dealer keeps failing to fix it, your state's
lemon law may require the manufacturer to replace it or buy it back. How
many repair attempts it takes, and how long you have to file, is set by
the state you bought in and by nothing on this page.
Complaints: NHTSA's ODI
complaint file, published October 2, 2026. One
complaint is one ODI number, which is how NHTSA counts them.
Recalls: NHTSA's recall
campaign API, newest campaign on this vehicle filed April 20, 2010.
Investigations: NHTSA's ODI
investigation file, published October 2, 2026.
A complaint is one owner's account and has not been verified by NHTSA or by
us. A vehicle with more complaints is not necessarily worse: models that
sold in larger numbers collect more of them. How this is counted.
G
Compiled and maintained by guarledes Independent developer and analyst