What it means
The positive (sourcing) side of the O2 sensor pumping current control circuit on bank 1 sensor 2 is open. Wide-band O2 sensors regulate oxygen concentration in a reference chamber by pumping current; the positive line is open here.
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 helps the control module regulate oxygen in the sensor’s reference chamber; this code sets when that positive current path is electrically open, so the module cannot control it as intended.
Common causes
Most likely first.
- Open positive current line
- Pin pushed back out of connector body
- Cracked solder joint inside the module or sensor
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 before disturbing the circuit.
- With the exhaust cool, inspect the sensor connector and harness for damage, corrosion, or a terminal pushed back into the connector body.
- Using the wiring diagram, identify the positive pumping-current path and check its continuity between the sensor and the module as the manufacturer specifies.
- Check for poor terminal contact or an open within the sensor or module connection, following the specified isolation procedure.
- If the external wiring and terminals pass, use the manufacturer's test procedure to distinguish an internal sensor fault from a module circuit fault.
Common fixes
- Repair an open or damaged positive pumping-current wire for Bank 1 Sensor 2.
- Reseat or replace a pushed-back or damaged connector terminal.
- Repair a poor connector contact or damaged harness section.
- Replace the Bank 1 Sensor 2 oxygen sensor or repair the module only if the manufacturer's tests identify that internal fault.
Can I keep driving?
A short drive is generally reasonable if the engine runs smoothly and no other serious warning is present, but arrange diagnosis soon. The control module may have limited oxygen feedback, which can worsen fuel economy or emissions and 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.