2008 Mercury Grand Marquis: sudden unintended acceleration

Filed Mar 9, 2021 · Acceleration · 78,013 miles · IL

I was driving in town and several times when I slowed down to stop at a stop sign or corner, after braking my car accelerated by itself. The engine revved up and made the car jump forward. I had to slightly release the brake snd brake harder to stop and avoid going into the intersection.

Filed Apr 27, 2016 · Engine, Fuel system · 75,000 miles · WA

The vehicle recently experienced two sudden acceleration events in two days 15 miles apart while decelerating and using the brake in what could only be related to an intermittent failure of the electronic throttle control. While on vacation during a 75 deg evening with the car at operating temperature I was navigating some s turns high on a bluff at 30mph. While coming into a corner with my foot on the brake and slowing to around 20mph the car suddenly accelerated. I hit the brakes hard, turned away from the corner to avoid going over the cliff and turned off the key. All this happened in less then 5 seconds. The next day mid afternoon after driving 20 miles I was leaving a park and traveling on a level straight road at around 25mph. Coming up to a stop sign I let off the gas and started applying the brake (like the day before) at about 15mph the car violently accelerated. I hit the brakes hard again, the rear tire started spinning and it pushed the car through the crosswalk past the stop sign and into oncoming traffic by about 4ft before I got the engine shut off. Once again this all happened in a matter of seconds. After a restart everything was normal again. I drove around 250 mi to get home without any further incident. Two weeks prior to these events I had the car at the dealer to program a new transponder key, reset the keyless entry and test the throttle to see if the initial deadband could be adjusted (no adjustment was done). After the incident I returned to the dealer and they said they have never heard of this problem, there are no recalls or tsbs, and the ECM would not datalog anything since there was no trouble light. They said there was nothing they could do. I consider this unsatisfactory, deem it a major safety defect and ford should be required to correct this immediately. A quick search reveals I am not the only one who has experience this.

Filed Aug 26, 2013 · Acceleration, Brakes · 87,500 miles · MA

When reversing out of driveway car accelerated on its own. Pressed brakes but car still moved backwards. Have skid marks in driveway to show for it. Threw car into neutral and turned off engine. Restarted and everything seemed normal. Drove car on trip and when reducing speed to slow down by pushing on brake car again accelerated and nearly hit another car. Again threw car into neutral and turned off engine. And again when restarting car everything seemed normal again. Wife is extremely afraid of driving car. Took car to dealer where it was purchased and was told that it may have been that I pushed the brake and gas pedal at the same time, this however, I believe is not the case. Dealership however kept the car for further investigation as to what the problem may be. Will hear in a day or two.

Filed Aug 15, 2013 · Acceleration, Brakes · 56,150 miles · GA

Vehicle was purchased used in june, 2011. While braking for a stop light, vehicle suddenly accelerated. Had to forcefully pump brakes to stop vehicle from hitting vehicle in front. Car returned to normal operation as soon as I got it stopped. Have had similar incidents a couple of times before, although not as bad as this one, however, at that time I thought maybe I had accidentally pressed the accelerator while braking. I know that was not the case this time.

Filed Sep 1, 2011 · Brakes · 63,000 miles · FL

Tl* the contact owns a 2008 mercury grand marquis. While driving approximately 35 MPH the contact began to depress the brake pedal to decelerate while approaching a traffic light. The vehicle suddenly accelerated on its own and there was an increase in the rpms. The failure occurred intermittently and over time became progressively worse. The vehicle was taken to the dealer for diagnostic testing. The technician was unable to diagnose the failure. The vehicle was not repaired. The approximate failure mileage was 63,000. Updated 10/4/11 *cn the dealer stated the brake pedal was adjusted to high, which may have interfered with the accelerator pedal. They lowered the automatic brake pedal . Updated 10/24/11

Filed Feb 10, 2011 · Acceleration · 4,500 miles · IL

Tl*the contact owns a 2008 mercury grand marquis. The contact stated that while using the cruise control, applying the brakes and resuming to normal the vehicle suddenly accelerated to higher speeds. The vehicle stopped after the brake pedal was applied. The vehicle was inspected by a dealer who was unable to diagnose the failure since they were unable to duplicate it. The vehicle was not repaired. The failure mileage was approximately 4,500.

Filed Jul 27, 2010 · Acceleration · 500 miles · MO · crash · 2 injuries

Tl* the contact owns a 2008 mercury grand marquis. The contact stated he started the vehicle and when depressing the brakes, the vehicle abnormally accelerated. The contact was unable to stop the unintended acceleration and the vehicle drove over a curb and crashed into a sign. The contact and passenger both sustained minor injuries to their necks from the seat belt. The vehicle sustained substantial front end damages. The vehicle was towed to the dealer and inspected but the cause of the unintended acceleration failure was not disclosed to the contact. The body damage was repaired and the contact traded the vehicle fro another. The failure and current mileages were 500. Updated 10/01/2010. *lj updated 10/04/10

Filed Jul 7, 2010 · Acceleration · 42,000 miles · VA · crash · fire · 1 injury

Tl*the contact owns a 2008 mercury grand marquis. After driving in reverse and shifting into drive from a stop light the vehicle surged forward and crashed into another vehicle. A police report was not filed. One person was reported injured. Smoke was seen coming from under the hood of the vehicle. The vehicle was towed to the contacts residence. The failure had not been diagnosed by the dealer. The failure and current mileages were 42,000.

Filed Feb 18, 2010 · Acceleration · 27,000 miles · NJ

Cruise control, sudden acceleration. Car went to 80 before I could stop it vehicle is a 2008 mercury grand marquis ls with 27,500 miles on it . The dealer replaced the ECM. This happened to my wife also at 35 MPH went to 65 before she stopped it.