What it means
The control circuit for the heater in the Bank 2 Sensor 1 heated oxygen sensor has a malfunction.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Bank 2 Sensor 1 is the heated oxygen sensor upstream of the catalytic converter on the engine's second bank. Its heater brings the sensor up to operating temperature sooner; this code sets when the computer detects a fault in the heater control circuit, which can delay fuel control and raise emissions.
Common causes
Most likely first.
- Heater element failed or open
- Damaged heater wiring or connector
- Blown heater circuit fuse
- Oxygen sensor failure
Symptoms
- Check-engine light on
- Oxygen-sensor heater may warm slowly
- Fuel economy may decrease
- Emissions may increase
How to diagnose it
- Record freeze-frame data and check how quickly Bank 2 Sensor 1 begins reporting after a cold start.
- Inspect the Bank 2 Sensor 1 connector and nearby exhaust-side wiring for heat damage, corrosion, looseness, or abrasion.
- Check the heater circuit fuse and power and ground connections using the vehicle wiring diagram.
- Test the Bank 2 Sensor 1 heater element and circuit continuity against the manufacturer's specification.
- If wiring, fuse, and connections pass, test the sensor heater control circuit and replace the sensor only if it fails.
Common fixes
- Reconnect or clean the Bank 2 Sensor 1 heater connector.
- Repair heat-damaged or chafed heater wiring.
- Replace a blown heater circuit fuse after checking for a short or overload.
- Replace Bank 2 Sensor 1 if its heater element fails the specified test.
Can I keep driving?
The vehicle may remain drivable, but avoid unnecessary trips because delayed sensor heating can increase fuel use and emissions, especially after cold starts. Address the fault before an emissions inspection.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.