Technical Definition:

O2 Heater Circuit (Bank 2, Sensor 1)

Technical Description:

The code refers to the front oxygen sensor on Bank 2. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it.

Possible Causes:

• O2 Heater element resistance is high
• Internal short or open in the heater element
• O2 heater circuit wiring high resistance
• open or short to ground in the wiring harness

Possible Symptoms:

O2 Sensor Heater Circuit Malfunction Bank 2 Sensor 1

Possible Solutions:

• Repair short or open or high resistance in wiring harness or harness connectors
• Replace oxygen sensor (cannot repair open or short that occurs internally to sensor)

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1
– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 circuit fuse
– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 harness is open shorted to ground
– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 circuit poor electrical connection
– Faulty Engine Control Module (ECM)

Specific Makes:

– Possible higher fuel consumption
– Possible more smoke from exhaust than usual