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Home >> Mazda >> 2011 >> CX-7 FWD L4-2.5L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Oxygen Sensor >> Testing and Inspection >> Heated Oxygen Sensor (HO2S) Inspection
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Heated Oxygen Sensor (HO2S) Inspection




HEATED OXYGEN SENSOR (HO2S) INSPECTION [L5]

HO2S Inspection

1. Warm up the engine to normal operating temperature.

2. Using the M-MDS, monitor the following:

- Vehicle speed (PID: VSS)
- Engine speed (PID: RPM)
- HO2S voltage (PID: O2S12)

3. Drive the vehicle and decelerate the engine speed by releasing the accelerator pedal fully when the engine speed is 3,000 rpm or more.

4. Verify that the HO2S outputs a voltage of 0.6 V or more, one time or more, then verify that the HO2S voltage (PID: O2S12) is 0.3 V or less while decelerating as shown in the figure.






- If not as specified, replace the HO2S.
Heated Oxygen Sensor (HO2S) Removal/Installation

HO2S Heater Inspection

1. Disconnect the negative battery cable.

2. Disconnect the HO2S connector.

3. Measure the HO2S resistance between terminals C and D.






- If not as specified, replace the HO2S.
Heated Oxygen Sensor (HO2S) Removal/Installation

HO2S heater resistance
- 2-50 ohms [normal temperature]

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