53 is as high as my Ford manual goes. I just fixed a 45 code on mine this weekend. After powering down, I cleaned up the area where the sensor is clamped to the radiator bracket. After that I found the sensor disconnect between the battery and the headlamp and cleaned it up too. Use electronic parts cleaner. I used some "Gold Ends" PCB treatment (spray) on the pins; keeps oxidization down and lubricates the plug.
