Mazda 6 Service Manual: Knock sensor inspection

Mazda 6 Service Manual / Fuel and emission control systems / Control system / 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 sensor.
If the knock sensor is okay, but PID value is out of specification, perform the Circuit Open/Short Inspection.

Specification
Approx. 4.87 megohms

Circuit Open/Short Inspection

1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION.)

2. Inspect the following wiring harnesses for open or short. (Continuity check)

Open circuit

If there is no continuity, the circuit is open. Repair or replace the harness.

- Knock sensor terminal A (harness-side) and PCM terminal 2S (harness-side)

- Knock sensor terminal B (harness-side) and PCM terminal 2P (harness-side)

Short circuit

If there is continuity, the circuit is shorted. Repair or replace the harness.

- Knock sensor terminal A (harness-side) and power supply

- Knock sensor terminal A (harness-side) and body GND

- Knock sensor terminal B (harness-side) and power supply

- Knock sensor terminal B (harness-side) and body GND

Camshaft position (cmp) sensor inspection

Caution When foreign material such as an iron chip is on the CMP sensor, it can cause abnormal output from the sensor because of flux turbulence and adversely affect the engine control. Be s ...

Knock sensor removal/installation

1. Remove the intake manifold. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.) 2. Remove the knock sensor attachment bolt to remove the knock sensor. 3. Install in the reverse order of removal. ...

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