Resistance Inspection

WARNING: This page is about a different car, the 2017 Mazda CX-9. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Remove the plug hole plate. (See PLUG HOLE PLATE REMOVAL/INSTALLATION .)
Remove the intake manifold. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION .)
Remove the KS. (See KNOCK SENSOR (KS) REMOVAL/INSTALLATION .)
Measure the resistance between KS terminals A and B.

Fig 1: Knock Sensor Connector Terminals

Courtesy of MAZDA MOTORS CORP.

If not as specified, replace the KS. (See KNOCK SENSOR (KS) REMOVAL/INSTALLATION .)

Specification (Reference)

504-616 kilohms [-40-130 °C {-40-266 °F}]