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.
KS(RH): KS terminals A and B

KS(LH): KS terminals C and D
- If not as specified, replace the KS. See KNOCK SENSOR (KS) REMOVAL/INSTALLATION [MZI-3.7] .
  KS resistance
  
  4.87 megohms
  
  Fig 1: Identifying KS Connector
  Courtesy of MAZDA MOTORS CORP.