2005 Subaru Outback: adaptive cruise control problems

Filed Mar 10, 2022 · Acceleration · 177,000 miles · MT

The contact owns a 2005 Subaru Outback. The contact stated that the vehicle was experiencing cruise control failures. Additionally, the contact stated while driving at 50 MPH up a steep hill of a bridge, the brake pedal was depressed and the vehicle decelerated significantly to 20-25 MPH. The accelerator pedal was depressed but failed to respond. The contact stated that the vehicle lost motive power and remained at the bottom of the hill facing an incline, while there was oncoming traffic. The check engine warning light and other unknown warning lights illuminated. The contact engaged the Sport mode first gear and the vehicle moved slowly. The contact continued to depress the accelerator pedal but the vehicle failed to respond. The contact switched to the slow lane and drove to the top of the incline and made a left turn off the end of the bridge downhill. The vehicle rolled down, allowing him to veer to the side of the road. The contact parked the vehicle. Upon inspecting the vehicle, the contact noticed that the engine was running at 2,000 RPM, even though the vehicle had no motive power. The contact turned off and restarted the vehicle. The contact shifted to drive and low gear, and he was able to drive the vehicle to an independent mechanic. The independent mechanic diagnosed that the throttle position sensor had failed. The vehicle was repaired. The dealer and the manufacturer were not notified of the failure. The failure mileage was approximately 177,000.

Filed Mar 19, 2019 · Engine, Fuel system · 162,167 miles · NC

Traveling at highway speeds (~75 MPH) during the morning rush hour on the highway, experienced sudden loss of throttle control and resulting deceleration. The check engine light glowed steady and the cruise light was flashing. After pulling off to the shoulder (across three lanes) and shutting the engine off and restarting the engine, throttle control resumed. Check engine light still glows steady and the cruise light is flashing with the cruise control not working.

Filed Nov 6, 2018 · Fuel system · 120,000 miles · ID

As I was driving, I all of a sudden lost all power and control from the gas pedal. The car decelerated and I was only able to idle forward. The gas pedal became completely unresponsive. I turned the car off and restarted it. The check engine light is on and the cruise control light blinks but the car drives fine until the the problem happens again. There is no way to predict it. I'm glad it has not happened in the middle of an intersection or a more dangerous situation where decelerating that quickly was more dangerous. The car is in motion on city streets when this happens. I believe the check engine code reading is p2138.

Filed Aug 28, 2018 · Acceleration · 174,000 miles · CA

1) recurring phantom revving (in neutral and/or clutch depressed, both while completely stopped and while slowing down from any and all speeds) upwards of 4-5k RPM with difficulty getting the rpms back to normal. Happens sometimes daily, sometimes constantly, sometimes it goes a few days without happening. 2) complete loss of pedal control/response (a "limp" pedal) while going 60mph on a freeway, managed to coast to safety and let the car sit for 10+ minutes, when it restarted and the throttle worked again. Stored code p2138, cel on and cruise control disabled. Have only driven the car a few times since, out of fear of losing pedal control again. -- online research has LED me to a number of possible solutions, most common being defective throttle position sensor connections (which frequently get exposed to the elements and corrode, apparently), bad accelerator pedal position sensor, and many people replaced the entire pedal assembly when the previous "fixes" did not solve the problem.

Filed Aug 18, 2017 · 27,779 miles · MI

Bought car in 2006. Check engine light came on after having a couple of months. Under warranty replaced oxygen sensor, went out after a month; also headlight went out. Had senior replaced again, went out again after 1 month. Wasn't under warranty, the sensor was but not the labor. Single income couldn't afford to keep replacing. My check engine light had been on for 9 years, and I haven't been able to use my cruise control. My 1 st subaru was a 1986; been driving one sense. Just thought you would like to know.

Filed Dec 6, 2014 · Acceleration, Electrical · 130,000 miles · CA

While driving on the highway at 65 MPH, the car would not accelerate. The check engine light came on and the cruise control light flashed. Once the car was turned off and restarted, the accelerator again engaged. This is an extremely dangerous (and common in subarus) malfunction. I was fortunate enough to be able to pull over on the side of the highway without incident.

Filed Jul 23, 2014 · Acceleration, Electrical · 112,000 miles · AZ

Just after getting off I-43 near sheboygan on frontage road my car lost all power and no acceleration on gas pedal. Check engine light came on and cruise control light was blinking. I had to shift to neutral and pull over to a shoulder. Turned the car off for couple of minutes while I check under the hood. Started the car just fine but check engine light was still on and cruise was blinking. Subaru mechanic read error code p2138 throttle/pedal position sensor/switch 'd'/'e' voltage rationality. They said it was caused by bad contacts on tps sensor by the gas pedal. He reset the code and it has not appeared again for almost a week. I am afraid of it going off again while my wife and kids are driving it on the highway. Does someone need to die before subaru takes action on this.

Filed Dec 4, 2013 · Acceleration, Engine · 102,075 miles · UT

Driving on interstate freeway, in heavy traffic, with the cruise control set, when the vehicle suddenly lost all power and throttle response. The "check engine" light came on, and the "cruise" light started blinking. Engine continued to run at high idle but speed and RPM were not maintained. I was lucky enough to cross 4 lanes of traffic and stop. Turned off the engine, which was running at 2200 RPM. After a brief stop and investigation, I was able to restart the engine and drive normally to an auto parts store. I scanned the obd ii code (dtc code) and found p2138 - throttle position sensor. No injuries, but this is a potentially deadly issue. Has recurred one time since.

Filed Nov 12, 2012 · Acceleration, Electrical · 80,000 miles · OR

While driving my outback lost suddenly lost all acceleration. The check engine light immediately came on and the cruise control light began to blink. The car continued to move forward but decelerated to about 15 MPH which nearly resulted in my being rear ended. I was able to get to the side of the road where I turned the car off and turned it back on. After doing this the car behaved normally expect the check engine and cruise control lights stayed on. After about an hour, both lights went off. Since then, this problem has recurred multiple times. I recently took the car to be repaired where the problem was diagnosed as a bad pedal assembly. However, I'm concerned that this problem will reoccur at speed and cause an accident.

Filed Nov 14, 2011 · Electrical, Fuel system · 99,000 miles · IN

Sitting at stop light - light changes green - no acceleration. Car will move at idle speed creep through intersection. Pull over stop turn car off. Restart w accelerator working but cruise control indicator flashing and check engine light on. Error code indicates pedal position sensor and dealer says entire pedal assembly needs replaced. New 'drive-by-wire' accelerator system for subaru in 2005. Repair: ~$200 with no change in assembly from what the service dept. Reports.

Filed Oct 30, 2011 · Electrical, Engine · VA

Second time this has happened. When in a stopped position and intend to pull out, motor running, but gas pedal does not engage. Push all the way to floor - still nothing. In order to correct, must turn off engine and disconnect battery cable so vehicle can reset itself. Also had problem when sitting still where vehicle began idling as if accelerator being pressed down - lasted 5-10 seconds then backed off. When purchased car used, had problems with cruise control not working and light flashing continuously. Found that injector had to be replaced - apparently tied to cruise mechanism. This corrected the problem but quite expensive to repair.

Filed May 20, 2011 · Engine · 67,446 miles · CA

Tl*the contact owns a 2005 subaru outback. The contact stated while driving on an incline the vehicle responded slowly. The cruise control and check engine light illuminated on the instrument panel. The dealership diagnosis determined that the turbo charger filter was clogged and the shaft in the turbo charger was broken. The vehicle was not repaired. The manufacturer was contacted. The failure and current mileage was 67,446.