where is the output speed sensor located on a 2011 Ford Escape

Hello - first, it's important to share whether you have a front wheel drive or 4 wheel drive Escape, and also important to share which engine your vehicle is equipped with. That alone makes it impossible to even guess at answering your question. That said, why are you guessing at an output shaft speed sensor to address your symptoms? If you have a wrench light, you have codes to review. However, you may not have a proper diagnostic tool to read codes and monitor related components. The wrench light could mean throttle body or transmission concerns. Hands on testing is needed. You are probably outside of your ability level here -- proper diagnostic tools, experience and reference materials are needed. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops