Technical Definition:

Heated Oxygen Sensor (HO2S) Heater Control Circuit Low (Bank 2 – Sensor 1)

Technical Description:

Possible Causes:

• A short in the heater circuit in the sensor
• A failed O2 sensor heater
• Wiring/connectors broken/frayed leading to sensor and/or relay
• Failed PCM/ECM

Possible Symptoms:

HO2S Heater Control Circuit Low Bank 2 Sensor 1

Possible Solutions:

• check for 12 volts at the heater circuit feed (hint: unplug the sensor and check at the wiring connector to do this measurement)
• check the ground circuit for continuity
• measure the resistance of the heater circuit (done on the sensor itself)
• measure the resistance and voltage of the wiring

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

Specific Makes: