Stratus L4-2.4L DOHC (1995)
Oxygen Sensor: Description and Operation
Heated Oxygen Sensor Circuit Operation
Circuit A14 is connected to the BUS bar in the Power Distribution Center (PDC), which connects to battery voltage. The contact side of the Automatic
Shut-Down (ASD) relay connects circuit A14 and circuit A142. A 20 amp fuse, located in cavity 5 of the PDC, protects circuits A14 and A142.
Circuit A14 also supplies voltage to the coil side of the ASD relay. The Powertrain Control Module (PCM) controls the ground path circuit for the coil
side of the ASD relay on circuit K51. Circuit K51 connects to cavity 67 of the PCM.
Circuit A142 splices to supply voltage to the upstream and downstream heated oxygen sensors.
The A142 circuit also splices to cavity 6 of the PCM connector. The input by circuit A142 tells the PCM that the ASD relay is energized.
Circuit K41 (K141 2.5L) delivers the signal from the upstream heated oxygen sensor to the PCM. Circuit K41 (K141) connects to cavity 30 of the PCM
connector.
Circuit K141 (K41 2.0L-2.4L) delivers the signal from the downstream heated oxygen sensor to the PCM. Circuit K141 connects to cavity 51 of the
PCM connector on the 2.0L, 2.4L engine and cavity 29 of the PCM connector on the 2.5L engine.
The PCM provides a ground for the upstream and downstream heated oxygen sensor signals (circuits K41 and K141) through circuit K4. Circuit K4
connects to cavity 43 of the PCM connector.
Circuit Z1 provides the ground path for the heater circuits in the sensors. This ground terminates at the right frame rail.
