Escape, Mariner, Escape Hybrid 2001-2005

Knock Sensor



The Knock Sensor (KS) is a tuned accelerometer on the engine which converts engine vibration to an electrical signal. The PCM uses this signal to determine the presence of engine knock and to retard spark timing.

Removal & Installation

  1. Raise and safely support the vehicle.
  3. Remove the intake manifold.
  5. Remove the bolt and the Knock Sensor (KS).
  7. To install, reverse the removal procedure and tighten mounting bolt to 15ft. lbs. (20 Nm).


Appropriate repair methods and procedures are essential for the safe, reliable operation of all motor vehicles, as well as the personal safety of the individual doing the work. This procedure provides general directions for repairing vehicles with tested, effective techniques. Following them helps to establish reliability. There are numerous variations in procedures, techniques, tools, and parts for repairing vehicles, as well as in the skill of the individual doing the work. This manual cannot possibly anticipate all such variations and provide advice or cautions as to each. Accordingly, anyone who departs from the instructions provided in this procedure must first establish that they compromise neither their personal safety nor the vehicle integrity by their choice of methods, tools, or parts.

  1. Disconnect the Knock Sensor (KS) harness connector and measure the resistance between KS + and KS - on the component side. The resistance should read between 4.39M-5.35M ohms. If resistance reading is not within specifications suspect a faulty KS.

    Click image to see an enlarged view

    Fig. Knock Sensor (KS) connector view-2.3L engine