Oxygen Sensor Relay: Description and Operation

Description

The oxygen (O2) sensor heater relay (ASD). Main Relay (Computer/Fuel System)

Operation

Oxygen Sensor Heater Relay:
If the vehicle is equipped with 4 oxygen sensors, a separate oxygen sensor relay is used to supply voltage to the sensor heating elements. This particular relay is used only for the 1/2 and 2/2 downstream sensors. Voltage for the other 2 sensor heating elements is supplied directly from the ASD relay. Application and ID Chrysler Corporation does not indicate a physical location in the power distribution center for the downstream oxygen sensor relay. Refer to Wiring Diagrams to determine which relay is used. Electrical Diagrams To avoid the simultaneous current surge needed to operate all 4 sensors, power is delayed to the 2 downstream heater elements by the PCM for approximately 2 seconds. The following P Codes concern 02 sensor heater circuits: P0031, P0037, P0051, P0057, P0032, P0038, P0052 AND P0058. A L L Diagnostic Trouble Codes ( DTC )