AI Damage2009 Mercury Mariner: common problems
Owners of the 2009 Mercury Mariner filed 315 complaints with NHTSA, most often about steering and engine. Details by component below, with sources.
Key figures
- Owner complaints
- 315
- involving a crash
- 9
What fails most often
- 1 Steering 53% of all complaints
- 2 Engine 17% of all complaints
- 3 Powertrain 14% of all complaints
- 4 Vehicle speed control 13% of all complaints
- 5 Electrical system 7% of all complaints
- 6 Fuel/propulsion system 5% of all complaints
- 7 Fuel system 5% of all complaints
- 8 Service brakes 4% of all complaints
- Steering: 167 complaints (53% of all), 3 of them with a crash reported by the owner.
- Engine: 53 complaints (17% of all).
- Powertrain: 44 complaints (14% of all).
- Vehicle speed control: 41 complaints (13% of all), 1 of them with a crash reported by the owner.
- Electrical system: 22 complaints (7% of all).
Engines and transmissions
US-market versions per EPA. On the right: how many NHTSA complaints name this engine or transmission type.
- 2.5 L · petrol · 4 cylnamed in 1 complaints
- 3 L · petrol · 6 cyl
- 2.5 L · hybrid · 4 cylnamed in 1 complaints
- automatic, 6-speed
- CVT
Drive: FWD, AWD
Symptoms owners describe
How many of the 315 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Steering | 167 | 3 | 0 |
| Engine | 53 | 0 | 0 |
| Powertrain | 44 | 0 | 0 |
| Vehicle speed control | 41 | 1 | 0 |
| Electrical system | 22 | 0 | 0 |
| Fuel/propulsion system | 15 | 0 | 0 |
| Fuel system | 15 | 0 | 0 |
| Service brakes | 14 | 2 | 0 |
| Engine and cooling | 7 | 0 | 0 |
| Wheels | 7 | 1 | 0 |
| Air bags | 4 | 1 | 0 |
| Electronic stability control | 4 | 0 | 0 |
| Structure | 3 | 1 | 0 |
| Suspension | 3 | 1 | 0 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
Drivers rear shock rusted off the wheel well causing wheel to snap and metal frame to hit the ground while I was traveling 40 mph. At this time the other wheels locked up and started squealing causing loss of control of vehicle shooting me across lanes and hitting curbs on both sides.
Power steering works or I have to manhandle the wheel to drive. If I turn car off and jiggle the steering wheel while turning it on sometimes it will come back other times it wonât.
And still no brakes. Have contacted ford corporate and they refuse to help or give me documentation to that effect. Ford cases are cas-28178357 and cas-27857368. I have two other mariners and this one just isn't right. Please advise my options.
Loss of power steering while driving error code "power steering assist error"
Have had multiple brake failures including an accident that my daughter was involved in as a result of brake failure. The brakes will work fine for a short period of time and then out of nowhere you step on the brake and there's just a soft pedal for about 3/4 of the was before you get a very soft brake.
The contact suffered a pinch nerve in the neck area and body bruises from the seat belt. The air bags failed to deploy with the substantial impact. The vehicle sustained severe front end damage and was towed to an impound facility temporarily. The manufacturer was notified of the defect.
The contact stated that while driving at undisclosed speeds on several occasions, the steering wheel started shaking abnormally. The contact added that on several occasions while driving at undisclosed speeds, the vehicle lost power steering functionality, but the vehicle regained power steering functionality shortly…
Check engine light, dropped fuel economy. Forced vehicle to shut off engine and no power, stop on freeway at full speed.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
Comparison
By complaint count this model year ranks 1,279 of 36,656 model years in the NHTSA data (top 3% most complained about).
On average one model year of the Mariner has 185 complaints (7 years in the data). This year has 315, above average.
What to check before buying
- Steering. Steering play, power assist, rack and tie rods after a wheel impact.
- Engine. Cold start, unusual noises, oil leaks and engine codes.
- Powertrain. Shift quality under load, harsh shifts, transmission codes, CV joints.
- Vehicle speed control. Accelerator pedal, cruise control, throttle codes.
Other years of this model
Questions and answers
What are the most common problems with the 2009 Mercury Mariner?
Owner complaints to NHTSA most often mention: steering, engine, powertrain. Total complaints: 315. The most frequent symptoms in complaint texts: steering or power steering problems (41%), warning lights, check engine (18%), loss of power / limp mode (14%).
How many service bulletins (TSB) were issued for the 2009 Mercury Mariner?
NHTSA lists 0 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2009 Mercury Mariner from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2009 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-05.