What is the signal from an O2 sensor used for?
This signal is a major input to the ECM, which it uses to control the air-fuel mixture and emissions. The O2 sensor measures the oxygen content of the exhaust. The O2 sensor’s sensing ability comes about by producing a small voltage proportionate to the exhaust oxygen content.
What are the colors of an O2 sensor wire?
O2 sensor wire colors MANUFACTURER SENSOR MFG 1 WIRE 2 WIRE 3 WIRE General Motors DELPHI VIOLET VIOLET VIOLET PINK BROWN BROWN
What happens to the O2 sensor when there is no oxygen?
The sensor is capable of generating a one-volt signal when there is no oxygen in the exhaust stream. The scope will display a peak voltage for each pressure wave. The controller will store the information for fuel trim. Most sensors have a heater to bring the sensor to operating temperature during a cold start and then shut down.
What is the reference voltage for an oxygen sensor?
The l 1 reference voltage for the sensor is 450 mV the same as the thimble-type sensor. The internal circuitry used in a wideband oxygen sensor produces a digital pulse width modulated signal that makes it quite different from a conventional oxygen sensor that produces an analog signal ranging from 0.1 and 0.9 volts.
What can an oscilloscope do for an oxygen sensor?
An oscilloscope is real time graphing voltmeter that can monitor the activity of an oxygen sensor or, if equipped with a hold feature, to capture a time and voltage sequence. What will the oscilloscope tell you about the operation of the sensor? It will supply voltage and a time trace according to the set up of the scope.
How does the O2 sensor work on a heater?
Note down which two wires correspond to the heater circuit and proceed to Test 2. The O2 sensor signal gives an indication of oxygen content sensed by the probe by sending an induced voltage that corresponds to the level of oxygen detected.
What is the return voltage of the O2 sensor?
The engine control module (ECM) monitors the O2 sensor bank 1 sensor 1 signal wire and is expecting only about 1.2 volts maximum. When the ECM sees a return voltage above 1.2 volts, it knows the sensor is shorted to the heater circuit that is running battery voltage.
What to do if your O2 sensor is shorted?
Monitors the O2 sensors for bank 1 sensor 1 to see if the signal is shorted to the heater circuit. Inspects the O2 sensor and the wire harness for any damage that could cause the short. Follows the manufacturer pinpoint tests for the diagnosis and replacement of the O2 sensor if the O2 sensor is internally shorted.