Warning! The sensors are located near the catalytic converter, which gets hot when the engine is running. To avoid burns, we check and remove the oxygen concentration sensors after the engine has cooled to a safe temperature.
To complete the work you will need:
- multimeter (in voltmeter mode);
- manhole or overpass (to remove the lower sensor);
- special key for the oxygen sensor.
Examination
1. We prepare the car for work (see «Preparing the car for maintenance and repair»).
2. Disconnect the wiring harness connector from the oxygen concentration sensor connector.
3. Connect «negative» voltmeter probe to «mass» engine. Turning on the ignition, check the supply voltage of the heating element at terminal B (the designation of the conclusions is applied on the block of the wiring harness).
Comment. The voltage at the output must be at least 12 V. If the voltage is not supplied to the block or it is less than 12 V, then the battery is discharged, the power circuit is faulty or the EED is faulty.
4. Connecting «negative» voltmeter probe to terminal C, measure the voltage between terminals A and C.
Comment. The voltage at the terminals should be 0.45 V. If the voltage does not enter the block or it differs by more than 0.02 V, then the power circuit is faulty or the computer is faulty.
Removing
1. Remove the wire holder for the oxygen concentration sensor from the hole in the protective screen.
2. Using a 22 mm wrench, unscrew the sensor from the catalytic manifold and remove the sensor.
Comment. A special key is required to unscrew the lower sensor. In the absence of such a key (see «Tools, fixtures and operating materials») you can cut off the handle of a conventional open-end wrench by 22 mm. If necessary, the lower sensor can be unscrewed from the removed catalytic manifold.
Advice. You can verify that the sensor is faulty by replacing it with a known good one.
Installation
Install the sensor in the reverse order of removal.