MarkS

My 2011 Ford Fusion Hybrid with about 53,000 miles on it began to refuse to go into EV mode while in gear unless the brake pedal was depressed. In addition, it developed a rough, fast idle at very low speeds. It behaved like it had a weak throttle return that on an older car would be fixed by replacing the throttle spring. The first try at solving the problem was to download the latest software as noted in the Technical Service Bulletin mentioned elsewhere in this thread for the ECM and cleaning the throttle body. That improved mileage a little but did not solve the problem. My service advisor did not think that there was a problem with the throttle body itself, because there were no error symbols or messages on the dashboard. The next step which appears to have solved the problem was to replace the throttle body and to re-initialize/reprogram the ECM software. (I actually had to tell them to do that, because I had learned from researching the problem on the internet that throttle body problems were quite common in Fords.) The cost for the repair at my local Ford dealer was just over $250 for parts and labor.