Resistance Inspection

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

Switch the ignition to LOCK.
Disconnect the KS connector.
Measure the resistance between the KS terminals A and B using an ohmmeter.
- If not as specified, replace the KS. (See KNOCK SENSOR (KS) REMOVAL/INSTALLATION [L5] .)
  Specification
  
  Approx. 4.63-5.11 megohms [ECT: 25 °C {77 °F}]
  
  Fig 1: Identifying Knock Sensor Connector Terminals
  Courtesy of MAZDA MOTORS CORP.