2009 Mercury Mariner problems & reliability
315 owner complaints filed with NHTSA for the 2009 Mercury Mariner, alongside 1 safety recall campaign. Last verified Aug 7, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several vehicles.
3 complaints report injuries (3 injured).
Federal crash records (FARS 2020–2023): 2009 Mercury Mariner vehicles were involved in 13 fatal crashes with 8 occupant deaths. Involvement counts are not adjusted for how many are on the road and do not imply fault or a vehicle defect.
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Steering | 167 | 53% |
| Engine | 53 | 17% |
| Power Train | 44 | 14% |
| Vehicle Speed Control | 41 | 13% |
| Electrical System | 22 | 7% |
| Fuel/propulsion System | 15 | 5% |
| Fuel System, Gasoline | 15 | 5% |
| Unknown OR Other | 15 | 5% |
| Service Brakes | 11 | 3% |
| Engine and Engine Cooling | 7 | 2% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
Common symptoms owners describe
Keyword analysis of complaint narratives; one complaint can describe several symptoms.
Mileage when problems occurred
Half of the failures with a reported odometer reading occurred by 97,050 miles (middle 50% between 66,243 and 122,526 miles), based on 250 complaints that included mileage.
Complaints by incident year
What owners report
“My vehicle was returned to me following a torque sensor replacement on 4/9/2026 in poor condition (locked steering and a catastrophic gash in the driver-side tire) rendering it undrivable and unsafe. Crossroads Ford of Prince George shop's inspection report claims the tire damage was pre-existing, I have conclusive…”
Wheels · filed Apr 11, 2026
“The contact owns a 2009 Mercury Mariner. 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…”
Steering · filed Mar 2, 2026
“My steering has been locking while I am driving and causing loss of steering and control of car. I have contacted crossroads dealer and I have not gotten a response as I am now aware there has been a safety recall on this vehicle.”
Steering · filed Feb 21, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Federal defect investigations
- Loss of power steering while driving
Defect Petition DP15001 · opened Apr 1, 2015 · closed Jun 14, 2018
- Electronic Throttle Body Malfunction
Preliminary Evaluation PE13003 · opened Feb 21, 2013 · closed Feb 28, 2014
Technical service bulletins
31 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2009 Mercury Mariner. The 10 most recent:
Replacing the original equipment SYNC/Navigation system with either an aftermarket SYNC/Navigation kit or modifying original SYNC/Navigation parts to provide additional features is not recommended nor supported on any…
SSM 47201 · Service Bulletin/Repair Instructions · issued Mar 30, 2018
The Accessory (Wireless) Keyless Entry Keypad can only be used with vehicles that are factory built with Remote Keyless Entry (RKE). The master code for the Accessory (Wireless) Keyless Entry Keypad can be retrieved…
SSM 47009 · Service Bulletin/Repair Instructions · issued Jan 10, 2018
The Accessory (Wireless) Keyless Entry Keypad can only be used with vehicles that are factory built with Remote Keyless Entry (RKE). The master code for the Accessory (Wireless) Keyless Entry Keypad can be retrieved…
SSM 47009 · Service Bulletin/Repair Instructions · issued Jan 10, 2018
Replacing the original equipment sync/navigation system with either an aftermarket sync/navigation kit or modifying original sync/navigation parts to provide additional features is not recommended nor supported on any…
SSM 46332 · Service Bulletin/Repair Instructions · issued Jan 24, 2017
Some 2008-2017 ford/mercury/lincoln vehicles equipped with sync may generate a vhr that identifies a concern with the brakes and suspension category indicating service is required due to a brake system warning lamp…
SSM 46132 · Service Bulletin/Repair Instructions · issued Oct 17, 2016
Some 2008-2017 ford/mercury/lincoln vehicles equipped with sync may generate a vhr that identifies a concern with the brakes and suspension category indicating service is required due to a brake system warning lamp…
SSM 46132 · Service Bulletin/Repair Instructions · issued Oct 17, 2016
The Powertrain Control/Emissions Diagnosis (PC/ED) manual has been revised for diagnosing electronic throttle bodies (ETBs). The ETC_ACT and ETC_DSD PIDs should not used to diagnose possible ETB concerns. The IDS has a…
SSM 46085 · Service Bulletin/Repair Instructions · issued Sep 21, 2016
6F35 TRANSMISSION - FLUID LEAK AT LEFT SIDE HALFSHAFT SEAL BUILT ON OR BEFORE 10/14/2013 ISSUE Some 2009-2014 Escape, 2009-2011 Mariner, 2010-2014 Fusion, 2010-2011 Milan, 2012-2014 Edge/Explorer, and 2013-2014…
16-0043 · Service Bulletin/Repair Instructions · issued Mar 15, 2016
Ford: in valve body, a worn solenoid pressure regulator valve has diagnostic trouble code (dtc) p0735 stored and indication of repair history was the valve body was not replaced previously. Model 2009-10 escape…
ASI-44733 · Service Bulletin/Repair Instructions · issued Sep 1, 2014
Mercury/ford: in one or more speed settings, electronic manual temperature control (emtc) a/c system is warm and/or lack blower motor operation in settings due to damaged blower motor resistor caused by water entering…
TSB-14-0157 · Service Bulletin/Repair Instructions · issued Aug 28, 2014
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
The 2009 Mercury Mariner has 1 NHTSA recall campaign — recall repairs are free at franchised dealers regardless of the vehicle’s age.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2009 Mercury Mariner?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.
- · Owners most often reported problems around 97,050 miles — budget accordingly if the car is approaching that mileage.