DTC P0059 OBDII is set when the vehicle’s computer detects a fault in the Oxygen Sensor (O2) heater element circuit number 1 of bank 2.
These sensors have a heater to preheat the sensor under cold start conditions. This is connected to the sensor wiring harness. The Control Area Network (CAN) connects the Powertrain Control Module (PCM) to the Oxygen Sensor wiring harness.
The information sent from the Oxygen Sensor to the PCM is the percentage of oxygen particles present in the exhaust compared to ambient oxygen. In case the PCM finds a resistance level of the O2 Sensor circuit higher than the limits already set by the manufacturer, the Check Engine lamp will light up along with this code.