Circuit Description

The DTC P0037 Heated Oxygen Sensor (HO2S) Heater Control Circuit Low Voltage Sensor 2 diagnostic monitors the operation of the HO2S 2 heater circuit. The heaters in the oxygen sensors increase the amount of time the sensor spends in Closed Loop fuel control operation or catalyst monitoring operation. The oxygen sensor heater is required by the post-catalyst HO2S 2 in order to maintain the high operating temperatures. The heater helps provide accurate oxygen content readings of the engine exhaust by the HO2S.