Town & Country V6-3.3L VIN R (2003)
there is a lesser amount of oxygen present (rich air-fuel mixture) the sensor produces a voltage as high as 1.0 volt. By monitoring the oxygen content
and converting it to electrical voltage, the sensor acts as a rich-lean switch.
The heating element in the sensor provides heat to the sensor ceramic element. Heating the sensor allows the system to enter into closed loop
operation sooner. Also, it allows the system to remain in closed loop operation during periods of extended idle.
In Closed Loop, the PCM adjusts injector pulse width based on the upstream heated oxygen sensor input along with other inputs. In Open Loop, the
PCM adjusts injector pulse width based on preprogrammed (fixed) values and inputs from other sensors.
DOWNSTREAM OXYGEN SENSOR
The downstream heated oxygen sensor input is used to detect catalytic convertor deterioration. As the convertor deteriorates, the input from the
downstream sensor begins to match the upstream sensor input except for a slight time delay. By comparing the downstream heated oxygen sensor
input to the input from the upstream sensor, the PCM calculates catalytic convertor efficiency. Also used to establish the upstream O2 goal voltage
(switching point).
