Huge win for car owners! All TSBs to be made public. The Center for Auto Safety just made the NHTSA (US Government) make public the full text of all TSBs from now on. They are the same organization that has petitioned the NHTSA & filed lawsuits to protect car owners over exploding gas tanks & other major safety issues. Whenever you drive in your car, you are safer thanks in part to a lot of work over the years by this small but very effective consumer advocacy group.

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hardly worth mentioning
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
57,001 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2009 Mercury Mariner electrical problems

electrical problem

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2009 Mercury Mariner Owner Comments

problem #10

Jan 132016


  • 118,382 miles


Problem started in December 2015, and got progressively worse. Engine would not start when ignition switch was turned to the start position. Had to make several attempts at it, and apply downward force on the key until the necessary contact was made. Once started it seemed to run normal. Ford dealer diagnosed the problem as a defective "ignition lock cylinder housing". they replaced it with a new one, part number 9L8Z*3511. Engine starts normally now. Total cost to me $527.74.

- Panama City, FL, USA

problem #9

Jun 222015


  • 118,000 miles
The contact owns a 2009 Mercury Mariner. While driving on an incline at an unknown speed, the vehicle suddenly decelerated and would not accelerate when the accelerator pedal was pressed. The service engine light illuminated prior to the failure. The vehicle stalled and was able to be restarted. The vehicle was taken to an independent mechanic where it was diagnosed that the electronic throttle control failed. The vehicle was not repaired. The manufacturer was not notified. The VIN was unavailable. The failure mileage was 118,000.

- Cincinnati, OH, USA

problem #8

Sep 302014

Mariner 4WD 6-cyl

  • 87,000 miles
The contact owns a 2009 Mercury Mariner. The contact stated that while driving approximately 10 mph the oil and battery warning indicators illuminated and the vehicle stalled. The vehicle restarted but the failure recurred on 2 other occasions. The vehicle was not taken to the dealer. The manufacturer was not made aware of the failure. Also, the contact stated that the vehicle would not start after the anti theft device warning indicator intermittently illuminated. The vehicle was not taken to the dealer. The manufacturer was made aware of the failure and advised the contact to have the vehicle towed to the dealer to have the computer reprogrammed. The approximate failure mileage was 87,000. Updated 4/21/15

- North Bergen, NJ, USA

problem #7

Jan 042015


  • 23,324 miles


Stopped to eat and keys would not come out of the ignition.

- Lake Zurich, IL, USA

problem #6

Aug 082014

Mariner 4-cyl

  • 48,678 miles
Fan blower motor only worked on 3rd and 4th setting. The blower motor resistor assembly (part no. 8G1Z*19A706) was diagnosed and replaced by dealer.

- Mokena, IL, USA

problem #5

Sep 092013

Mariner 6-cyl

  • 50,000 miles
While driving the vehicle's dash lights and head lamps go black for 2-5 minutes before coming back on. My car was taken to the dealer multiple times and was unable to be diagnosed. I also contacted Ford directly as this problem poses a hazard during night driving. To date there has been no resolution. While driving the vehicle will lose all acceleration, this issue happens while driving down the road posing a hazard as you have to turn the vehicle off an on again to regain control.

- Allen Park, MI, USA

problem #4

Oct 092013


  • miles


My Mercury Mariner 2009 has had issues for the past year in regards to the vehicle unexpectedly goes into "limp home mode" at reduced power, like while sitting at traffic light or stop sign. Also, the wrench light will go on while driving and I lose acceleration power. I can push the gas pedal down and nothing happens, the engine is still on but no acceleration power. I will coast until I can get to a safe spot to have to power it off and then restart it. This is very dangerous while driving in rush hour back and forth to work each day. The car lags when accelerating and also pumps while when coming to a stop. I do not feel safe in the car and wish I had never bought it. I can't even make a trip to the store without worrying about the wrench coming on or it going into limp mode.

- Cleveland, OH, USA

problem #3

May 192013

Mariner 6-cyl

  • 40,850 miles
This is the fourth time since purchasing the car at carmax in October 2012 that the car has "shut off" without warning at low speed when close to parking or driving slow--without rhyme nor reason--I had it diagnosed at carmax to no avail, then Cherokee Ford to no avail (where I purchased a new battery), then at christian brothers auto where they replaced the spark plugs and coil.( I have an extended warranty so my cost was 200dollars) the problem continues. I have done research and see the throttle body is most likely the culprit and a safety alert is on the web from consumer report and Ford forum and North Carolina safety board---I am having the trottle body replaced at my expense--my daughter drives this vehicle and I want it safe! apparently this involves this model 2009-2012.

- Johns Creek, GA, USA

problem #2

Jan 022013

Mariner 4-cyl

  • 51,777 miles
After going through a car wash, I received a warning on the dash that there was a problem and that I should find a safe place to stop. When I returned home and stopped the car it would not restart. The same thing happened on February 16,2013, again after going through a car wash. The local dealer was able to get the vehicle running, but would not say that it was repaired.

- Big Spring, TX, USA

problem #1

May 022011

Mariner 6-cyl

  • 32,000 miles
The vehicle stalls randomly. I may be driving or idling and the car stalls. It is easily started again by putting the car in neutral and turning the key. I have had Ford look at it several times and they first changed the battery and then second changed the gas filter. The problem still exists.

- Millington, TN, USA

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