How to check the lambda sensor on a car
Hello ! Many motorists are concerned about . And it works if I have a car lambda probe ? How to check that it is working on a car in the home ? I will answer. Yes you can . And it is not necessary to have a diagnostic system . Everything is much easier. We need a digital multimeter . Lambda sensor ( oxygen sensor ) has from one to four wires.
With a single wire (usually black ) lambda is unheated . With two wires one wire signal , the other heater .
Also the case with the lambda probe at three and four wires . Where there are three of them , one signal wire and the other two heaters . Where the four wires , then it one wire signal (black), the gray wire is the weight of lambda , two white – heater .
A little understood with wires. On those vehicles where the lambda sensor is installed without a heater , you can put a heater . To do this, you need to install additional intermediate relay. On cars with a lambda probe heater to raise the probe can not be without a heater .
To check the oxygen sensor ( lambda sensor ), connect the negative lead of the multimeter probe to the motor housing . Identify contacts on the oxygen sensor . As I said , the wires can be from one to four. Connect the positive lead of the multimeter probe to the signal wire on the oxygen sensor . Warm up the engine to normal temperature.
Accelerate the engine to 2500-3000 r / min for 3 minutes to warm up the oxygen sensor. Allow the engine to run at higher speeds and verify the inclusion of the oxygen sensor . Voltage sensor should have a value of 0.2 to 1 volts and a frequency included 8-10 times in 10 seconds . If the voltage is approximately equal to 0.45 volts, and does not change, the oxygen sensor is simply not working. It is safe to unscrew the sensor and throw under the fence .
I recommend using the self or using the scanner to consider the fault codes. Moreover, if the sensor is not working , the control unit switches to open loop or uses a fixed voltage of about 0.45 volts to support lambda ratio of approximately one. Also check the oxygen sensor heater circuit . If the heater circuit is defective , the oxygen sensor may not be able to achieve the target temperature and normally does not work . This is done as follows:
When a tester check the battery voltage at the power supply chip oxygen sensor heater . If no voltage , check the wires going to the relay or the ignition switch . Also check the ground connection lambda probe heater .