Error Code P1135: Air/Fuel Ratio Sensor Heater Circuit...P1135 Toyota: A.

There is a general fault in the air/fuel sensor heater circuit.

To create accurate voltage signals, the air/fuel ratio sensor needs to reach a certain operating temperature.The quicker the air/fuel ratio sensor gets to that minimum temperature, the quicker it will send accurate signals to the engine control module.

A heater element is built into the air/fuel ratio sensor to reach the required operating temperature.The air/fuel ratio sensor element is controlled by the ECM based on signals from the engine.The state of the circuit is determined by the voltage signals received through the heater element circuit and the factory specifications.