DTC : P0135: General Description
A heater for the sensor element is embedded in the rear air/fuel ratio (A/F) sensor (bank 1, sensor 1), and it is controlled by the powertrain control module (PCM). It is activated and heats the sensor to stabilize and speed up the detection of oxygen content when the exhaust gas temperature is cold. The PCM monitors the rear A/F sensor (bank 1, sensor 1) heater output (return check). If the return signals do not meet the command value (for heater activation) for a set time, the PCM detects a malfunction and stores a DTC.