2009 Mercury Mariner Problems

What owners report

Owners of this model year most often write about losing power steering assist, usually at low speed in turns or at startup, with the assist sometimes returning after a restart. Many complaints mention that a 2014 steering recall either did not cover their vehicle or was done as a software reprogram and the problem came back. A smaller but consistent group of complaints covers engine stalling or limp mode tied to the electronic throttle, and delayed or harsh automatic transmission behavior.

1. 1
   Steering

   Power steering assist quits (hard steering, fault message)

   • 131 complaints (42%)
   • median 120,000 mi at 9.3 yrs old (100 state mileage)
   • 2 mention a crash, fire or injury
   • owner-quoted repair $1,351 (median of 12 quotes)
   • filed 2013–2026

   Owners describe the electric power steering assist cutting out, often during low-speed turns, parking maneuvers or right at startup, leaving the wheel very hard to turn. Many say a 'Power Steering Assist Fault' message or a chime appears, while others report no warning at all. Some report the assist returns after the engine is shut off and restarted, and others say it stays out. Complaints frequently mention that the vehicle had the 2014 steering recall performed, sometimes only as a software update, and that dealers then told them their VIN was not covered or the repair was not covered; some dealers diagnosed a steering torque sensor or steering column assembly. Mostly reported between roughly 90,000 and 190,000 miles, commonly during turns and low-speed maneuvers.

   Recall 14V2840003 related service bulletins

   What to check: Ask whether the 2014 steering recall (14V284000) was completed and, if so, whether the torque sensor or steering column was replaced rather than only reprogrammed. On a test drive, try full-lock turns at parking speed and watch for the power steering fault message.

   2 excerpts from owner complaints in NHTSA records

   “My 2009 Mercury Mariner has an issue with the steering. Sometimes it works but most of the time it does not. There will be times when it does work it will go out in mid turn and jerk the wheel straight, sometimes causing me to swerve into traffic or out of my lane. I did hear that this particular vehicle was involved in a recall but I was not sure how to get that information.”

   NHTSA complaint #11297955, filed 2020-01, 108,000 miles

   “Suddenly the steering was extremely difficult to turn. I was in a stationary position and then tried to turn. Fortunately I was in a parking lot when the problem occurred. If I had been on the highway it could have been a very dangerous situation.”

   NHTSA complaint #11388194, filed 2021-01, 132,000 miles
2. 2
   Engine

   Engine stalls or drops into limp mode (throttle body)

   • 83 complaints (26%)
   • median 73,000 mi at 5.0 yrs old (79 state mileage)
   • owner-quoted repair $467 (median of 8 quotes)
   • filed 2009–2023

   Owners describe the engine dying or losing power while driving, sometimes at highway speed, with the wrench or check engine light coming on and little or no response from the accelerator. Several say the car restarts and drives normally afterward, sometimes repeating several times in a short distance. Complaints mention dealers finding stored throttle body codes (P2111 or P2112) and replacing the electronic throttle body, and some report the acceleration problem returning. Reported from about 38,000 to 130,000 miles, often while accelerating or at steady cruise.

   3 related service bulletins

   What to check: Ask whether the throttle body has been replaced and whether any stored throttle codes were cleared. During a test drive, pay attention to hesitation, a wandering idle, or the wrench light coming on under acceleration.

   2 excerpts from owner complaints in NHTSA records

   “I was traveling down the interstate at approx. 70 MPH when suddenly, I felt a jolt. At this time, I lost power upon depressing the pedal. I slowly moved to the emergency lane and stop the vehicle. A wrench tool illuminated on the instrument panel. I then turned the vehicle off. I was able to restart the vehicle. As I proceeded to continue on my route, as I was accelerating, approx. 25 - 30 MPH, the incident repeated if self. …”

   NHTSA complaint #10587713, filed 2014-05, 71,666 miles

   “Driving about 40 MPH vehicle lost speed. Could not accelerate . Came to a stop point had to turn off vehicle. Turn back on and was ok. Happened twice. Went for a diagnostic and was reported a problem with throttle actuator control system -.stuck closed. ???? Check with dealer $435.00 . Check online and found out that Mercury Mariner is having this problem but no recall ?”

   NHTSA complaint #10531830, filed 2013-07, 126,000 miles
3. 3
   Brakes

   Brake pedal sinks toward the floor, weak braking

   • 13 complaints (4%)
   • median 100,000 mi at 10.8 yrs old (10 state mileage)
   • 2 mention a crash, fire or injury
   • filed 2011–2022

   Owners describe the brake pedal traveling much farther down than usual, sometimes to the floor, and needing heavy pressure to slow the vehicle. Some complaints say the problem followed ABS activation and point to the ABS hydraulic control unit; others say shops replaced pads and related parts without resolving it. Several owners say their VIN was not included in a brake-related campaign and repairs were paid out of pocket. Reported from about 90,000 to 170,000 miles.

   What to check: Test the pedal with the engine running and again after a hard stop from low speed, and ask for service records on the ABS hydraulic unit and brake fluid. A soft or long pedal is worth having inspected before buying.

   2 excerpts from owner complaints in NHTSA records

   “After ABS activated brake padel became soft. My vehicle has a simlar problem expained under ''safety recall 19s54 ' anti-lock brake system hydraulic control unit valve function''. Eventhough ford recalled several unites, my VIN did not list under the recalled units.”

   NHTSA complaint #11349677, filed 2020-08, 150,000 miles

   “When using the brakes there's a loss of about half of the brake pedal, and most likely the ABS system. The part retails for $1,747.32. The problem from talking to mechanics and searching is apparently sticking valve(s) which in turn makes the brake fluid by-pass half of the system. In other words you only have the use of part of the brake system. Our car has 170k miles but that's ~ 90% highway miles, we bought it ~6yrs ago with 15k miles, which means the brakes don't get that much use. …”

   NHTSA complaint #11373310, filed 2020-10, 165,000 miles

Buying note. Service records matter most on this model year: confirm whether the 2014 steering recall was completed and in what form, since many owners report the assist problem returning afterward. A careful test drive at parking-lot speeds, on the highway and after a hard stop gives a reasonable read on steering, brakes and transmission.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.