DeVille V8-4.6L VIN Y (1998)
The oxygen sensors also incorporate a heating element inside of the sensor housing. This heating element is energized with the ignition On and allows
the sensors to reach operating temperatures quickly. The PCM can then use oxygen sensor information sooner after engine startup.
OPERATION
An oxygen sensor acts like a battery because it creates its own signal voltage once it reaches operating temperature. This voltage is produced when the
oxygen content in the exhaust stream is different than the oxygen content in the atmosphere. A lean condition (high oxygen content in exhaust) will
produce a low voltage (near 0 volts) and a rich condition (low oxygen content in exhaust) will produce a high voltage (near one volt). The PCM provides
a reference signal voltage (0.45 volts) and a ground to the sensor. The PCM reference voltage is necessary because the oxygen sensors do not provide
their own voltage until they reach operating temperature.
The PCM uses oxygen sensor information during Closed Loop operation to constantly adjust fuel control to reduce exhaust emissions. Because the
oxygen sensors provide information sooner after engine start-up, exhaust emissions are reduced. Faulty oxygen sensors will cause various driveability
conditions and should set a DTC.
