Which parts fail
Components named in complaints (accelerator pedal, throttle, sudden acceleration, cruise control).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2006 Subaru Legacy owners, lightly cleaned up (personal details are redacted by NHTSA).
I experienced two issues with the electronic throttle position sensor in my 2006 Subaru Legacy. The first time I was traveling at approx. 35 MPH and the RPM's began increasing rapidly. I was in traffic and unable to pull off to the side safely when the engine completely stalled. I sat there thinking that the motor was going to blow up if I attempted to start it again. I called my mechanic and he thought that it could be the throttle position sensor, as he has replaced many of them on subarus. I was able to start the car and move off to the side of the road to make sure that it was not going to do it again. The car was then taken to the mechanic where he cleaned the sensor and said if I have a problem again then I should replace it. …
One morning after starting my car I noticed the check engine light was on. As I decided to drive the car down to a local mechanic, I noticed that I had no acceleration power. The car was on, engine was running, but whenever I pushed the gas pedal nothing happened. The car would idle high and coast when put in drive or reverse, but would not accelerate as I pushed the pedal. There have been numerous counts of this happening to people across the country. Luckily I wasn't on the freeway when this happened.
I was driving about 40 MPH when I realized that I had no control of the pedal/gas. When I looked at the dash board the check engine light was on and the cruise control light was flashing. I had to pull over and when I put the car in park the vehicle revved high. It took about 15 minutes before the car restarted. I was able to drive home. The diagnostic machine indicated that it was the throttle pedal position sensor.code p2138. The throttle body was replaced. I am still having the same issues.
Tl* the contact owns a 2006 Subaru Legacy. While driving various speeds, the vehicle lost acceleration and the check engine and cruise control warning indicators illuminated. The contact coasted to the side of the road. The vehicle was towed to the contact's residence. The vehicle was taken to the dealer, but the technician could not find a code to identify the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 80,000.
While driving the check engine light suddenly came on and the gas pedal stopped being responsive. Luckily I was able to get to the side of the road and put the vehicle in park. When in park the engine revved to about 2.5K RPM and stayed there. I shut off the vehicle and restarted it and it stayed at that level. After several more tries it eventually started up and ran fine. The check engine light code is p2138 for the throttle position sensor.
While driving in traffic all of a sudden the gas pedal stops working, the check engine light illuminates the cruise control light illuminates but the pedal has no effect on the engine the car slows very quickly and comes close to causing an accident. I have checked forums on the web and found where many others have had same issues. The forum is subaruoutback.org please check this sight the code is p2138 any help will be appreciated
Tl* the contact owns a 2006 Subaru Legacy outback. The contact stated that while driving approximately 35 MPH, the accelerator pedal was depressed to the floorboard however, the vehicle failed to respond. The vehicle was not taken to be diagnosed nor repaired. Neither the dealer nor the manufacturer were contacted nor notified of the failure. The approximate failure mileage was 125,000. The VIN was not available.
Car would not accelerate upon entering the highway after pushing on the gas pedal the car wouldn't do anything . I was able to get off to the side and missed being hit from behind from on coming traffic...I notice check engine light and flashing cruse control light... Second time some weeks later it did the same thing this is very dangerous because you never know when this will happen.
Tl* the contact owns a 2006 Subaru Legacy. The contact stated that the vehicle would not accelerate when the accelerator pedal was depressed. In addition, the check engine and the cruise control warning lights remained illuminated. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was 140,000. The VIN was not available.
Driving at 55 MPH vehicle accelerator became unresponsive. Check engine light came on as well as cruise and sport lights. There was no power at the pedal. I had to coast to a stop in traffic lane. Engine surged up and down in RPM's. Shut key car off. After a couple minutes, car started and driving was resumed like nothing happened. Warning lights remained on in dash.
Acceleration complaints in other Legacy years
Frequently asked questions
How common are acceleration problems on the 2006 Subaru Legacy?
NHTSA has 30 complaints about the speed control & acceleration of the 2006 Subaru Legacy, 34% of the model year's 87 complaints. The component named most often is cruise control (1 mentions).
Is there a recall for 2006 Subaru Legacy acceleration problems?
No. NHTSA lists no speed control & acceleration recall for the 2006 Subaru Legacy, though it has 7 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2006 Subaru Legacy acceleration problems start?
Half of the complaints with a recorded mileage happened before about 107,000 miles, and 3% before 25,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.