Eldorado V8-4.6L VIN Y (1994)
Powertrain Control Module (PCM) Wiring
PURPOSE
The oxygen sensor is mounted in the exhaust system where it can monitor the oxygen content of the exhaust gas stream. The oxygen sensor acts as
an electro-chemical cell or battery. A voltage is produced in response to the amount of oxygen in the exhaust stream, compared to the oxygen
content in the atmosphere. A lean mixture, high O2 content in the exhaust, will produce a low voltage. A rich mixture, low O2 content in the
exhaust, will produce a high voltage. Oxygen sensor voltages range from approximately 100 millivolts to 900 millivolts. By monitoring the voltage
output of the 02 sensor, the PCM will determine what fuel mixture command to send to the injectors. All models have two oxygen sensors (right
and left).
DESCRIPTION
The ECM/PCM provides a 0.45 volt reference signal to the oxygen sensor. When the oxygen sensor is cold (below 200°C), the oxygen sensor
signal voltage will be around 0.45 volts and the PCM will keep the system in open loop operation. When the oxygen sesor is warm (above 200°C),
