Which tool can be used to monitor the activity of an O2 sensor?
Evaluating the OBD I fuel control function involves using a voltmeter or lab scope to measure the voltage activity of the oxygen sensor itself. Lab scopes are the more accurate method because the voltage range and switching pattern of the oxygen sensor’s voltage input to the PCM can be observed as a waveform.
Why do you need an upstream O2 sensor?
Upstream O2 sensors are part of the engine’s fuel feedback control loop, and are necessary to maintain good fuel economy and low emissions. A conventional upstream O2 sensor is essentially a rich/lean indicator that the powertrain control module (PCM) uses to balance the air/fuel ratio.
How to test O2 sensors with an automotive scan tool?
If you have an auto scanner with some power they offer a menu of sensors to observe. You can also record the information in snap shot mode and review it off the car. Finally, some tools can run a specialized O2 monitor test. At the end of the test it lists the sensor activity and location.
How does the PCM monitor the O2 converter?
The PCM compares the readings of the upstream and downstream O2 sensors to see how well the converter is reducing pollutants in the exhaust. When the engine is first started, the downstream O2 sensor’s output will mirror that of the upstream O2 sensor, and flip-flop back and forth between rich and lean.
Where are the O2 sensors on a V6 engine?
On V6, V8 and V10 engines, there are at least one upstream O2 sensor in each exhaust manifold. This allows the computer to monitor the exhaust oxygen from each bank of cylinders separately. On a scan tool, the output signal from the two upstream sensors is usually referred to as Bank 1 Sensor 1 and Bank 2 Sensor 1.
Upstream O2 sensors are part of the engine’s fuel feedback control loop, and are necessary to maintain good fuel economy and low emissions. A conventional upstream O2 sensor is essentially a rich/lean indicator that the powertrain control module (PCM) uses to balance the air/fuel ratio.
The PCM compares the readings of the upstream and downstream O2 sensors to see how well the converter is reducing pollutants in the exhaust. When the engine is first started, the downstream O2 sensor’s output will mirror that of the upstream O2 sensor, and flip-flop back and forth between rich and lean.
On V6, V8 and V10 engines, there are at least one upstream O2 sensor in each exhaust manifold. This allows the computer to monitor the exhaust oxygen from each bank of cylinders separately. On a scan tool, the output signal from the two upstream sensors is usually referred to as Bank 1 Sensor 1 and Bank 2 Sensor 1.
Can you test an O2 sensor with a scanner?
Now that you know how to check an O2 sensor with a scanner, it is time to dive into what an O2 sensor is. Placed in the exhaust, an oxygen sensor is used to give a measurement between the oxygen in the gas exhaust and the oxygen in the air. Some people think that it measures just oxygen, but that is not truly accurate.