Cruise Control problems of the 2004 Subaru Legacy

Sudden deceleration. Occurred at complete standstill, 25mph and 65mph, speed appears not to be a factor. Check engine light comes on and cruise control quits and cruise light blinks and engine defaults to 1500rpm, all happens simultaneously, ergo no warning. Complete loss of gas pedal control. Intermittent problem. Can happen a few times a day or nothing for a week. Tends to happen more from a cold engine start and within 3 miles of thee start. Very dangerous if on freeway, especially in fast lane and pulling out onto street, etc.

The contact owns a 2004 Subaru Legacy. The contact was driving approximately 30 mph when the vehicle decelerated independently. The check engine warning light was illuminated as the cruise control warning light began flashing. In addition, the vehicle would not accelerate over 10 mph. The vehicle was taken to the dealer for diagnostic testing where the technician advised that the throttle position sensor would have to be replaced. The vehicle was repaired however, the failure recurred six times. The throttle was replaced twice. The electronic control module was replaced and the manufacturer was made aware of the failure. The vehicle was not repaired. The approximate failure mileage was 20,000. The consumer stated the throttle ceased to function normally and the check engine light illuminated. The vehicle, would then slow down immediately and would only move at a speed of approximately 10 mph. The consumer stated he learned if he came to a full stop and restarted the vehicle three or four times, the throttle would re-engage and he would be able to resume normal speed, sometimes for some distance , and other times for only a short distance before it failed again. When the vehicle's electronic control module was checked by a mechanic, it showed a code p2138. It appeared that the engine computer unit was involved because when it rest the throttle worked again, briefly. The mechanic reset and it ran normally for three days before failing. Updated 05/16/13.