Most common 2009 Mercury Mariner problems
Share of the 315 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Mercury Mariner complaints by model year
Best Mariner years: 2007, 2005, 2006. Years to avoid: 2008, 2010, 2009. Compare all years →
2009 Mercury Mariner recalls (1)
Steering › Electric power assist system
Ford Motor Company (Ford) is recalling certain model year 2008-2011 Ford Escape and Mercury Mariner vehicles manufactured August 18, 2006, through September 11, 2010. The affected vehicles have a steering torque sensor that may not be able to properly detect driver steering input.
Remedy: Ford will notify owners, and dealers will update the software for the power steering control module (PSCM) and the instrument cluster module, free of charge.
NHTSA defect investigations
Federal safety investigators have looked into 2 possible defects involving the 2009 Mercury Mariner:
Electronic Throttle Body Malfunction
On February 21, 2013, the Office of Defects Investigations (ODI) opened Preliminary Evaluation PE13-003 to investigate allegations of electronic throttle body (ETB) failures resulting in sudden reduction of engine power in model year (MY) 2009-2013 Ford Escape, Fusion, Mariner and Milan vehicles.
Loss of power steering while driving
On May 27, 2014, amended June 2, 2014, Ford Motor Company (Ford) submitted a Defect Information Report (DIR) to NHTSA describing a safety defect that may result in a sudden loss of power steering assist while driving in approximately 746,067 model year (MY) 2008 through 2011 Ford Escape vehicles equipped with electric power assisted steering (NHTSA 14V-284, Ford 14S05).
What 2009 Mercury Mariner owners say
Steering all 167 →
The contact called on behalf of his wife who owns a 2009 Mercury Mariner. The contact stated that while his was driving approximately 25 MPH, the vehicle lost power steering assist making it difficult to steer the vehicle. The power steering assist warning light was illuminated. The driver pulled over to the side of the roadway safely where her husband arrived with his trailer to tow the vehicle back to the residence. The following day the vehicle was driven to the dealer in manual steering mode. The dealer diagnosed the vehicle and confirmed the failure with the power steering. The dealer related the failure to NHTSA Campaign Number: 14V284000 (Steering) however, the VIN was not included. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 136,200.
The contact owns a 2009 Mercury Mariner. The contact stated while driving 30-35 MPH, the vehicle lost power steering functionality. The contact was able to pull to the side of the road. The contact turned off and restarted the vehicle after 15-20 minutes, and the power steering became functional. The contact was able to continue driving. The contact stated that the failure recurred several times while driving. The dealer was contacted and charged a fee for diagnostic testing. The vehicle was not diagnosed or repaired. The contact related the failure to NHTSA Campaign Number: 14V284000 (Steering); however, the VIN was not included. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 131,000.
Engine & cooling all 60 →
While traveling approximately 35 MPH, driving in a straight line on a city street in traffic, the ABS abruptly applied the brakes - hard! The ABS light came on and a "check brake system" warning message was displayed. Also, the electrical system shut down and the engine lost power. After about 5 seconds, power was restored and vehicle was able to proceed. This occurred approximately 8 times over a two mile distance. During the last 4 times, the engine died, lost power completely, and needed to be turned off and restarted to continue. This failure was a dangerous safety hazard. Vehicle was towed to albuquerque Lincoln Volvo. The problem was diagnosed as a failed ABS module, 9l8z. The dealer replaced the ABS module with a faultly module. A second ABS module was installed and the vehicle was deemed repaired. The dealer did not return the defective part for analysis.
Power of vehicle drastically decreased while driving down secondary road. Had just enough power to pull over to side of the road. Pushed down accelerator in park and neutral but no power. Turned off. Restarted and resumed normal driving. Suspect electronic throttle body. The Ford dealership will not replace without a diagnostic fee because they state it is not a recall, although an internal vehicle health report states "there are recalls for your 2009 Mercury Mariner at this time" notice # 13n03 electronic throttle body extended coverage I believe using the word recall constitutes misrepresentation when in fact Ford motor company states it is just a customer satisfaction program to alleviate them from costs and any wrong doing. It is a very dangerous safety concern.
Transmission & drivetrain all 44 →
I have been intermittently losing power steering. The code is B1342. After researching, it looks like Ford is aware of this problem but is unwilling to fix the issue. This fix must be done at a dealership since it is a software issue and going to cost $2,000. Obviously losing power steering when going at fast speeds is incredibly dangerous for myself and others. There is no check engine light that comes on when the issue arises.
On 1/1/2016 I was driving on 495 w in queens, ny heading back to manhattan where I live. Out of nowhere the car began jerking, a wrench light on the dash panel came on (which I never saw before) and I could tell the car was decelerating. I tried hitting the accelerator again, the car would jerk, the engine was revving but was barely moving. I knew I had to pull over and luckily I was able to navigate to the shoulder of the road. This was an extremely dangerous situation. I am a confident driver, however, a less confident or timid driver most likely would have panicked and gotten into a potentially serious collision.
2009 Mercury Mariner engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 2.5L 4-cyl hybrid | CVT | FWD | 34 / 31 / 32 |
| 2.5L 4-cyl hybrid | CVT | 4WD/AWD | 29 / 27 / 28 |
| 2.5L 4-cyl | 6-speed automatic | FWD | 20 / 28 / 23 |
| 3.0L 6-cyl | 6-speed automatic | FWD | 18 / 26 / 21 |
| 2.5L 4-cyl | 6-speed automatic | 4WD/AWD | 19 / 25 / 21 |
| 3.0L 6-cyl | 6-speed automatic | 4WD/AWD | 17 / 24 / 20 |
EPA ratings. Class: SUV.
Frequently asked questions
Is the 2009 Mercury Mariner a good car?
Based on 315 owner complaints filed with NHTSA, the 2009 Mariner rates avoid: 3.3× as many complaints as a typical year of the Mariner at the same age. It is one of the Mariner years we suggest avoiding. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2009 Mercury Mariner?
The steering — 167 complaints, 53% of all complaints for this model year, most often about electric power assist system. Next are the engine & cooling (60) and transmission & drivetrain (44).
How many recalls does the 2009 Mercury Mariner have?
There is 1 recall for the 2009 Mercury Mariner, the most recent from May 29, 2014 (electric power assist system). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the Mercury Mariner?
The best years by complaints, compared at the same age, are 2007, 2005 and 2006. Years to avoid or approach with caution: 2008, 2010 and 2009. See the full Mercury Mariner years comparison.
At what mileage do 2009 Mercury Mariner problems happen?
The median mileage reported in complaints is about 97,000 miles; 15% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.