P0036 – HO2S Heater Control Circuit (Bank 1 Sensor 2)
The P0036 diagnostic trouble code (DTC) indicates that the Engine Control Module (ECM) has detected a malfunction in the Heated Oxygen Sensor (HO2S) heater control circuit for Bank 1 Sensor 2. This oxygen sensor is located downstream of the catalytic converter and uses an internal heating element to reach operating temperature quickly, allowing the ECM to monitor catalytic converter efficiency and exhaust emissions.
Symptoms of P0036
- Check Engine Light illuminated.
- Increased exhaust emissions.
- Reduced fuel economy.
- Delayed oxygen sensor operation after a cold start.
- In most cases, little or no noticeable change in engine performance.
Common Causes
- Faulty Bank 1 Sensor 2 oxygen sensor.
- Open or short circuit in the heater wiring.
- Blown heater fuse.
- Corroded or loose electrical connector.
- Poor ground connection.
- Faulty ECM (rare).
How to Diagnose P0036
- Scan for additional diagnostic trouble codes.
- Inspect the oxygen sensor wiring and connector.
- Check the heater circuit fuse.
- Measure the heater element resistance with a multimeter.
- Verify battery voltage and ground at the heater circuit.
- Replace the oxygen sensor if the heater element has failed.
Possible Repairs
- Replace the Bank 1 Sensor 2 oxygen sensor.
- Repair damaged wiring or connectors.
- Replace a blown fuse.
- Repair an open or shorted heater circuit.
- Replace the ECM only after confirming all other components are functioning correctly.
Can You Drive With Code P0036?
Yes, the vehicle can usually be driven with code P0036, but the fault should be repaired as soon as possible. A failed heater circuit can increase emissions and prevent the ECM from accurately monitoring catalytic converter efficiency.
Estimated Repair Cost
- Oxygen sensor replacement: $100–$350
- Wiring repair: $50–$200
- Fuse replacement: $10–$30
- ECM replacement (rare): $500–$1,500
Related Trouble Codes
- P0037 – HO2S Heater Control Circuit Low (Bank 1 Sensor 2)
- P0038 – HO2S Heater Control Circuit High (Bank 1 Sensor 2)
- P0030 – HO2S Heater Control Circuit (Bank 1 Sensor 1)
- P0136 – O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
- P0141 – O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)