P1135 BMW O2 Sensor Heater Circuit Low Voltage Bank 1 Sensor 1

Possible causes

– Faulty HO2S Bank 1 Sensor 1
– HO2S Bank 1 Sensor 1 harness is open or shorted
– HO2S Bank 1 Sensor 1 circuit poor electrical connection

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)