Technical Description
The Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1) is a problem with the heating circuit of the front oxygen sensor on Bank 1.
What does that mean?
This diagnostic trouble code (DTC) is a generic powertrain code that applies to OBD-II equipped vehicles. The specific repair steps may vary depending on the make and model of the vehicle.
The heated circuit in the oxygen sensor is responsible for reducing the time needed to enter closed loop. When the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to the oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. If the ECM determines, based on coolant temperature, that too much time elapsed before the oxygen sensor began operating properly, it will set the P0135 code.
Symptoms
You may notice poor fuel economy and the illumination of the MIL (Malfunction Indicator Lamp).
Causes
A code P0135 may indicate that one or more of the following has occurred:
