OEM Jeep Liberty Knock Sensor

Jeep Liberty Knock Sensor Parts and Q&A

• Knock Sensor
  4606093AF
  Q: How to Install a Knock Sensor on a 3.7L Engine on Jeep Liberty?

  A:

  Check the type (LEFT) and large bolt head on the sensor to know the correct position, otherwise the Powertrain Control Module (PCM) may receive incorrect signals. Clean the holes keep the knock sensors are meant to be inserted into the cylinder block before you place them. Avoid tightening the sensor mounting bolts either too hard or too lightly, otherwise, this can cause problems for both the knock sensor and spark plug control; to be sure, use the recommended torque of 15 +/- 2 ft.lbs (20 Nm) (176 in.lbs) for all mounting bolts, but this is relatively light for an 8 mm bolt size. According to the instructions, the foam liner on the bolt's threads is only there to hold the bolt during assembly; apply no sealants, adhesives or thread lockers to these bolts. After tightening the bolts, connect the knock sensor wires to those on the back side of the Intake Manifold and place the intake manifold in position.
• Knock Sensor
  56041679AC
  Q: How to Identify and Replace a Knock Sensor on the Left Side on Jeep Liberty?

  A:

  A tag on the left knock sensor displays the word "LEFT" and a larger bolt and the PCM must recognize the difference between left and right knock sensors to keep them separated. The knock sensors bolted into the cylinder block beneath the Intake Manifold can be removed by first unplugging them from the main engine wiring harness near the rear of the engine and then removing the intake manifold. Afterward, take the sensor bolts out, remembering that the foam piece around them is for keeping the bolts in place during plant assembly; do not place any adhesive or sealant on these bolts. After taking out the sensors from the engine, give the mounting holes a thorough cleaning, then put in the sensors back into the cylinder block. Make sure not to tighten or loosen the sensor mounting bolts too much, since this can affect both knock sensor operation and the performance of the spark, so use 20 N.m (176 in. lbs.) torque on the bolts as specified. Last, fit the intake manifold again and join the knock sensor wiring to the engine wiring at the back of the manifold.