Yes a code 52 is a knock sensor, We have tried replacing the sensor with some luck. Also replace the wire lead to the sensor as well.
This code can be set when the engine gets excessive mileage on it and the clearances become out of tolerance so the sensor hears internal knocking noise and cant control it which in turn give you the code.
Please let us know happens so it will help others.
Wednesday, January 4th, 2017 AT 11:39 AM