Jumper wire
Caution

Voltmeter
is used by connecting the positive (+) probe (red lead wire) to the point where voltage will be measured and the negative (-) probe (black lead wire) to a body ground.

Ohmmeter
Caution

Connectors
Precautions before weldingMazda 6 Service Manual: Knock sensor inspection
Note
Perform the following test only when directed.
Resistance Inspection
1. Turn the ignition switch to LOCK.
2. Disconnect the knock sensor connector.
3. Measure the resistance between the knock sensor terminals A and B using an
ohmmeter.
If not as specified, replace the knock sens ...
Mazda 6 Service Manual: Power Steering
Power steering is only operable when the engine is running. If the engine
is off or if the power steering system is inoperable, you can still steer, but
it requires more physical effort. If the steering feels stiffer than usual
during normal driving or the steering vibrates, consult an A ...