P0147
O2 Sensor Heater Circuit Bank 1 Sensor 3
Oxygen sensor heater
Generic OBD-II
Medium
What it means
P0147 means the heater circuit in the bank 1, sensor 3 oxygen sensor isn't working correctly. Oxygen sensors have a built-in heater so they reach operating temperature quickly; when the heater circuit fails, the sensor takes longer to work and the ECM stays in open loop longer. It doesn't affect drivability but delays emissions readiness.
Medium
Can I keep driving? Yes — the car drives normally; this is a heater-circuit fault that mainly delays the sensor reaching operating temperature and affects emissions readiness.
Common symptoms
What you'll notice
- Check-engine light on
- No noticeable change in how the car drives
- Slower to reach closed-loop operation, especially in cold weather
- May fail or not complete an emissions readiness test
Common causes
Most likely first
- Failed heater element inside the bank 1, sensor 3 oxygen sensor — the most common causeLikely
- Blown fuse feeding the sensor heatersCommon
- Corroded connector or damaged wiring in the heater circuitCommon
- Poor ground or open in the heater supplyLess often
- Rarely, an ECM faultLess often
How to diagnose & fix
Work through it in order
- Check the fuse that supplies the oxygen-sensor heaters.
- Measure the heater element's resistance at the sensor against spec.
- Inspect the connector and wiring for corrosion, damage, or an open.
- Replace the bank 1, sensor 3 oxygen sensor if the heater is open or out of spec.
- Clear the code and confirm the heater monitor passes.
FAQ
Quick answers
Is it safe to drive with P0147?+
Yes. A heater-circuit fault doesn't affect drivability or safety. It's worth fixing so the sensor works promptly and the car can pass emissions.
Can I just clear P0147?+
Clearing it is temporary — if the heater element or its circuit is faulty, the code returns after the next cold start.
Related codes
Often seen with P0147
Read & clear P0147 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX