What it means
The bank 1 sensor 2 oxygen sensor positive current control circuit is above the expected range. The code does not by itself establish a short to voltage or predict mixture and fuel-economy effects.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Bank 1 Sensor 2 is the downstream wide-band oxygen sensor after the engine’s first cylinder bank. Its positive pumping-current circuit lets the control module regulate oxygen in the sensor’s reference chamber; this code sets when the circuit signal is higher than expected, but does not by itself prove the wire is shorted to voltage.
Common causes
Most likely first.
- Short to B+
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
How to diagnose it
- Record freeze-frame data and check for other Bank 1 Sensor 2 oxygen sensor codes to determine whether the fault is isolated.
- With the exhaust cool, inspect the sensor connector and harness for pinched wiring, damaged insulation, corrosion, or loose terminals.
- Check whether the positive pumping-current wire is contacting a powered wire or has heat damage near the exhaust.
- Use the wiring diagram to test the circuit for an unintended connection to battery power and check continuity and terminal contact as specified by the manufacturer.
- If the external wiring passes, test the sensor and module circuit using the manufacturer's procedure before replacing components.
Common fixes
- Repair positive pumping-current wiring pinched against a powered circuit.
- Repair damaged or heat-hardened harness insulation.
- Clean or replace corroded or loose connector terminals.
- Replace the Bank 1 Sensor 2 oxygen sensor or repair the module circuit only if testing confirms an internal fault.
Can I keep driving?
A short drive is generally reasonable if the engine runs normally, but arrange diagnosis soon and stop if it begins running poorly. The oxygen sensor feedback fault can worsen fuel economy or emissions and may cause a failed emissions test.
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.