What it means
The negative pump current control of the intake air oxygen sensor on bank 2 reports a circuit open condition. Wide-band lambda regulation on the intake side is impaired.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The bank 2 intake-air oxygen sensor is a wide-band sensor that uses a pump cell to measure oxygen in incoming air for control-module regulation. P2AEF sets when the module detects an open in the negative pump-current control path, leaving that part of the sensor circuit unable to operate normally.
Common causes
Most likely first.
- Open in pump current wire
- Internal open in pump cell
- Pin pushed back out of connector body
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 compare bank 2 intake-air sensor readings with other available bank data to see when the fault occurs.
- Locate the bank 2 intake-air oxygen sensor using service information and inspect its connector for a pushed-back pin or poor seating.
- Trace the negative pump-current control wire from the bank 2 sensor and inspect for breaks, chafing, or heat damage.
- With the circuit isolated as directed by the manufacturer, check continuity through the negative control wire and connector terminals.
- If the wiring passes, test the bank 2 sensor pump cell by the manufacturer's procedure for an internal open.
Common fixes
- Reseat the bank 2 sensor connector or terminal that has backed out.
- Repair an open or damaged negative pump-current control wire.
- Replace a connector terminal that no longer makes reliable contact.
- Replace the bank 2 intake-air oxygen sensor if its pump cell is internally open.
Can I keep driving?
A short, gentle drive is usually possible if the engine runs normally, though fuel consumption and emissions may worsen with bank 2 intake-side regulation impaired. Avoid longer drives if rough idle or hesitation develops.
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.