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 Outback owners, lightly cleaned up (personal details are redacted by NHTSA).
The engine will randomly loose power. This has happened three times now. You must coast to a stop, turn the key off and try to restart the car. Sometime it will take several tries to restart. I see this as a real safety concern in heavy traffic. Especially so if heavy traffic makes it impossible to reach the side of the road safely. The service code points to the throttle peddle position sensor. Reading some of the internet forums it seems to be a fairly common issue. Of course internet forums must be considered carefully. However with the above said I see this issue as a real safety concern. Not only for my safety but those around me if this happens in heavy traffic. Thank you
The accelerator pedal position sensor is faulty. It is prone to wear in these vehicles based on my research. This caused my car to go into limp-mode on the highway, rapidly cutting my speed in half. The accelerator provides no response until vehicle was restarted. The ECU put out the code P2138 for loss of voltage in throttle system.
While traveling down a residential road, my 2006 Outback sedan lost acceleration control and went into limp mode in which it was only idling and had no control from accelerator. The check engine light illuminated and the cruise control light began blinking. I turned the engine off from drive, moved the shifter to park and restarted the vehicle after a minute or so. It started up fine but seems to be idling low, sputtering and hesitating a little. Especially when reversing slowly or pressing the accelerator very lightly from idle. A mechanic nearby said the problem code was reading "bad throttle position sensor." I believe the error code was p2138. Upon researching the issue and as others have suggested, this is supposedly a common problem yet no real reason for the failure can be identified. …
P2138 code - throttle issue --- today as I was driving to work, luckily on a side street,when the check engine light came on and the cruise control light began to blink. Then I lost power to the engine while it was still running. I normally take the highway to work but this day there was snow and ice so I decided to take the side streets instead. I pressed the gas pedal with no response. I coasted to a side street and turned in with no incident, thank god. I was near a Toyota dealership and I asked for their help but they said they did not work on Subaru. I was just about to call aaa when I thought to restart the car to see if it would go so I could take it somewhere else. I gave it gas and it went. The check engine light and cruise control was still on. …
I was traveling on a 3-lane highway at the posted mileage (60 MPH). Simultaneously the check engine light came on and the gas pedal lost all power. The cruise light was also flashing. I tried flooring the gas pedal, but the vehicle continued to lose power and the speed rapidly decreased to less than 20 MPH. This happened with absolutely no warning and no time to get off a busy thoroughfare. This occurred at approximately 3:00 pm, so fortunately the traffic was not extremely heavy. I was able to cut across 2 lanes of traffic that was going 60 MPH +, exit on an off-ramp, and get to a safe location to call for a tow truck to take the vehicle to dealership for repair. The outcome was code p2138 (accelerator sensor). The sensor was replaced at a cost of $340. I purchased this vehicle new in 2006, and have kept it well maintained at the dealership per their service schedule. …
I was driving with my 10 month old in the car when it suddenly began to deccelerate. I pressed on the gas pedal and got no response. The check engine and cruise control lights began flashing at this time as well. Fortunately I was on a rural road (speed limit 40 MPH) and was able to limp along to a pull off. I turned the engine off and let it sit for 5 minutes. When I turned the car back on I was able to drive again. The check engine light was on when I initially started the car but turned off when I began driving again. The same event occurred 4 days later when I was taking my 4 year old to preschool. I turned off a 25 MPH street into his school when the check engine light came on and the gas pedal quit working. I should note that when the gas pedal "quits working" the car will not let me go above 15 MPH. …
Driving in busy traffic on freeway, highways, and streets, cruise and engine lights came on, no response when applying gas pedal, car coasted into slow cruise, eventually down to about 15 MPH. Again, no response to applying gas pedal. That happened sporadically. Had near fatal accidents a couple times then it stopped and two or three weeks later throttle turned on revving up to 500 in idle, over 300 when driving. Trying to stop at intersections, brake malfunctioned, nearly hit several people trying to get home. Engine racing out of control. This stopped briefly, drove errand, and withno foot on gas pedal, car was speeding up on highway uphill and still accelerating at 78 MPH. Brakes did not work consistently, jumped a curb, when trying to pull over and turn off engine. Had to have car towed. Repair of throttle senior $365 at local dealership in portland, or. …
My car has been experiencing episodes where it suddenly stops accelerating while I am driving. This has happening both on city streets, and on the highway. It's mostly about 5 minutes after I initially turned the car on, but not always. I will be driving normally and all of a sudden the check engine lights and cruise control lights will come on and then the car will instantly stop accelerating with no additional warning. The most recent time this has happened, my car actually sped up without me pressing on the gas pedal. The code reads p2138. After turning my car off and waiting a few minutes it drives fine (although sometimes the lights are still on). I have had a Subaru dealership check out the problem and after looking at the car for about one week they could not find the problem. …
I was driving straight down the highway going about 50-60 MPH and out of nowhere my throttle peddle failed to work. My car immediately slowed down to a crawl and I had to quickly find a safe place to pull over on a road with barely any shoulder. Luckily not many cars were on the road so I did not have to worry about a pile-up accident. The check engine light came on and stayed on while the cruise control light began to flash on and off. After turning the car off and waiting a few minutes I decided to try and drive the car again since I was in an area with no service and it was below freezing outside. The car started and I could use the throttle peddle and the car drove with no problem for about 5 miles before the same exact thing happened. Luckily someone drove by and I was able to catch a ride with them to get service and call a tow truck. …
While in motion, rapidly applying the brakes causes check engine light to come on, the cruise control indicator flashes and control of the accelerator pedal lost. The car essentially becomes limp and is not able to receive input from the accelerator pedal at this time. Turning the car off and letting it sit for 30 seconds and then turning the car back on re-provides control to the accelerator pedal. At this time the check engine light is still on. After a couple of days the check engine light goes off. My local authorized Subaru shop traced the issue to a faulty accelerator pedal sensor. The entire assembly was replaced and the car is operating nominally. …
Acceleration complaints in other Outback years
Frequently asked questions
How common are acceleration problems on the 2006 Subaru Outback?
NHTSA has 98 complaints about the speed control & acceleration of the 2006 Subaru Outback, 35% of the model year's 277 complaints. The component named most often is accelerator pedal (5 mentions).
Is there a recall for 2006 Subaru Outback acceleration problems?
No. NHTSA lists no speed control & acceleration recall for the 2006 Subaru Outback, 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 Outback acceleration problems start?
Half of the complaints with a recorded mileage happened before about 100,000 miles, and 3% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 0 injuries to speed control & acceleration problems on this model year. If you notice symptoms, have the car checked before driving further.
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.