On several occasions since I've owned this vehicle (I am original owner) when I step on the brakes hard the engine accelerates. Recently it has gotten worse and I know I'm not touching the accelerator. Today it was so bad the I was standing on the brakes with both feet and burning rubber. I shifted to park and the engine went onto max acceleration. I shut of the engine and restated and found it…
2006 Mercury Grand Marquis cruise control problems
severe 29 complaints filed with NHTSA · avg repair $600 · see cruise control across all vehicles →
Failure mileage
Complaints
29
Recalls
0
Avg fix
$600
6crashes
1fire
4injuries
When does it fail?
Of the 29 cruise control complaints filed for the 2006 Mercury Grand Marquis, here's the actual mileage breakdown — failures cluster heaviest at 50,000-75,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Of the 5 model years of Mercury Grand Marquis we track for cruise control problems, this one carries the most owner complaints on file — 29.
Owners have filed 29 cruise control complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
The failure pattern owners describe
Owners describe multiple unintended acceleration events across this model year. The most common scenario: driver applies brake to stop, but engine RPM increases and vehicle continues moving or surging forward. In several cases, extreme brake pressure was required, and some owners had to shift into Neutral or turn off the ignition to regain control. A few incidents occurred at traffic lights or stop signs while the vehicle was stationary; one owner reported the engine maxing out after shifting to Park.
Other owners report accelerator pedal sticking at full throttle during highway passing, forcing them to slam the pedal repeatedly to reset the system. A separate group reports problems immediately after cruise control use—the vehicle accelerates uncontrollably and brake or cruise control buttons become ineffective. Several owners experienced violent lurches or gear surges when shifting into Drive or Reverse.
One owner reported excessive engine revving (2000 RPM) each cold morning, a different symptom but related to throttle control. Two crashes and multiple near-misses are documented. Diagnostic scans and dealer inspections consistently returned no codes or identified failures. One independent mechanic identified a throttle body assembly as the culprit and mentioned a Ford service bulletin on this part; another replaced both throttle position sensor and throttle body. Most owners who brought vehicles to dealers received no diagnosis and no repairs.
Same Mercury Grand Marquis cruise control reports on nearby years: 2005 · 2007 · 2008
Failure modes owners describe
Unintended acceleration when braking
Engine unexpectedly accelerates or maintains high RPM when driver applies brake pedal to stop, often with significant force required to control the vehicle. Occurs both while moving and while stopped at traffic lights or stop signs.
When: Intermittent, ranging from very early (2,000 miles) to high mileage (170,000 miles); some incidents reported within weeks of ownership
Symptoms owners cite: Engine RPM increase or rev-up when brake pedal applied; Vehicle continues to accelerate despite brake application; Excessive pressure on brake pedal required to slow vehicle; Vehicle surges forward while stopped
Repairs/costs cited: Throttle body assembly replacement reported in one case; throttle position sensor and throttle body replaced in another. Multiple owners reported dealer inability to diagnose; no repairs made in many cases.
Recalls/TSBs owners mention: Ford bulletin noted for throttle body on 2006 Grand Marquis models. Some owners reported manufacturer was notified but no recalls mentioned in narratives.
Stuck accelerator pedal at full throttle
Accelerator pedal becomes stuck at wide-open throttle position and does not respond to foot release. Requires repeated, forceful depression of accelerator pedal to reset the system and restore normal engine response.
When: Occurs during highway passing maneuvers and at full throttle; happened three times in two weeks for one owner
Symptoms owners cite: Accelerator pedal stuck at full throttle; Engine RPM climbs rapidly and uncontrollably; Vehicle accelerates to 75-90 mph uncontrollably; Releasing accelerator pedal has no effect; Repetitive slamming of accelerator pedal required to regain control
Repairs/costs cited: Computer diagnostics showed no abnormalities or codes; mechanics cleaned throttle contacts; no permanent repair documented
Uncontrolled acceleration after cruise control use
Vehicle continues to accelerate or exhibits uncontrolled engine behavior immediately after cruise control engagement or deactivation, with brake application and cruise control switch ineffective at restoring normal operation.
When: Occurs at speeds of 60 mph and higher; incidents reported at 33,000 miles on one vehicle that crashed twice
Symptoms owners cite: Vehicle abnormally accelerates at 60 mph and higher speeds; Cruise control deactivation (brake pedal or switch) does not stop acceleration; Engine continues to idle violently after brake applied; Brake pedal depression ineffective at reducing engine power
Repairs/costs cited: No repairs made; dealer unable to duplicate failures and blamed floor mats or driver error
Recalls/TSBs owners mention: Dealer attributed to floor mats or driver mistake (accidental cruise control resume button activation)
Gear lunge and violent acceleration on shift engagement
Vehicle lurches forward suddenly or engine races excessively when shifting into Drive or Reverse, or at startup after placing vehicle in gear. Occurs with brake pedal applied and requires shifting to Neutral to stop the surge.
When: Occurs early in vehicle lifecycle; one instance at 27,000-29,000 miles
Symptoms owners cite: Vehicle lurches forward unexpectedly when shifting to Drive or Reverse; Engine races (motor revs excessively) after gear engagement; Rapid acceleration despite brake pedal application; Occurs even with brake held firmly; Requires Neutral shift and ignition shut-off to stop vehicle
Repairs/costs cited: Dealer unable to identify cause; no repairs documented
High idle RPM at cold start
Engine revs to elevated RPM (2000 RPM reported) when cold-started in the morning, holding high revs for several seconds before gradually returning to normal idle, raising owner concerns about engine wear.
When: Occurs each morning on cold engine start
Symptoms owners cite: Engine revs to 2000 RPM on cold startup; Remains at elevated RPM for 5-6 seconds, then 1000 RPM for 2 seconds; Gradual decrease to normal idle; Concern about engine damage from high revs with minimal oil circulation
Synthesized from 29 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 3 most recent
Tl* the contact owns a 2006 mercury grand marquis. While driving 45 MPH, the vehicle accelerated independently. The contact depressed the brake pedal, but the vehicle did not stop. The contact was able to place the vehicle in neutral and depress the brake pedal in order to stop the vehicle. The vehicle was not taken to be diagnosed or repaired. The failure was intermittent. The dealer was not…
Stopped at railroad crossing. Train moving. 1 car ahead of me at railroad. Stop. I was completely stopped. After being stopped for about a minute my car suddenly accelerate and slammed into car in front of me pushing car forward in the side of moving train. My car also slammed into train and was reversed and stopped on railroad post. During this time I could not stop vehicle. The vehicle was…
Had cruise control trouble with your 2006 Mercury Grand Marquis?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the cruise control problem on the 2006 Mercury Grand Marquis?
It's a meaningful issue. 29 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $600.
At what mileage does the cruise control typically fail?
Across the 23 complaints that reported odometer mileage, most cruise control failures cluster between 26,000 and 102,000 miles, with the median around 45,800. A quarter of owners report trouble before 26,000; a quarter make it past 102,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $600 for cruise control repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to cruise control?
No active recalls currently cover cruise control issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2006/Mercury/Grand Marquis.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.