Air-fuel ratio sensor (Mazda CX-5KE)

Removal and installation the air-fuel ratio sensor

Attention.

• A hot engine and exhaust system components can cause various burns. Turn off the engine and wait until they cool before removing exhaust system components.
• Avoid contact with flammable objects (for example, electrical tape) with exhaust manifold and muffler.

Note:

• If leak test spray enters the air flow hole of the air fuel ratio sensor, it may cause the air fuel ratio sensor to malfunction.
• When removing the air-fuel ratio sensor, wrap a rag around the bottom of the sensor to prevent spray from entering the air flow opening.

1. Disconnect the negative battery terminal.

2. Remove the decorative engine cover.

3. Disconnect the air-fuel ratio sensor connector.



4. Remove the clamp from the heat shield.





5. Remove the wire harness from terminals A and B of the electrical wiring.



6. Remove the air-fuel ratio sensor using a special tool.



7. Installation is carried out in the reverse order of removal.

Note: Secure the electrical wiring in clamp A by placing heat shrink tubing on it.

Note: Secure the wiring clamps so that they are on either side of clamp B.

Checking the air-fuel ratio sensor

1. Connect the M-MD8 device to the DLC-2 diagnostic connector.

2. Turn on the ignition (engine on).

3. Warm up the engine to operating temperature.

4. Display the following parameters on the M-MDS device:

• V88 (car speed)
• RPM (engine speed)
• 02511 (air fuel ratio sensor output current)

5. Drive the vehicle, reducing engine speed by fully releasing the pedal from a speed of 3000 rpm or more.

6. Make sure that the output current of the air-fuel ratio sensor (02811 according to the M-MD8 device) is not less than 0.25 mA, as shown in the figure. If the obtained values are not normal, replace the air-fuel sensor with a new one.

Checking the heating of the air-fuel mixture sensor

Caution: A hot engine and exhaust system components can cause various burns. Turn off the engine and wait until they cool before removing exhaust system components.

1. Disconnect the negative battery terminal.

2. Disconnect the air-fuel ratio sensor connector.

3. Measure the resistance between terminals A and E of the air-fuel ratio sensor.

Note: Air-fuel ratio sensor heating resistance: 1-10 Ohm (at normal temperature).