Technical Definition:

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

Technical Description:

Possible Causes:

Possible Symptoms:

• Lengthened time needed to achieve closed loop
• MIL (Malfunction indicator lamp) illumination
• Possibly decreased fuel mileage depending on fault

HO2S Heater Control Circuit Bank 2 Sensor 1

Possible Solutions:

• Failed or damaged heater circuit element inside the HO2S
• Open on the O2 sensor heater’s ground circuit
• Open or short on O2 sensor heater’s B+ battery feed
• Possible ECM failure

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: