What it means
The negative pump current control of the intake air oxygen sensor on bank 1 reports a circuit high 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 wide-band intake-air oxygen sensor on bank 1 uses pump current to help the control module measure incoming-air oxygen. P2AE8 indicates that the negative pump-current control circuit is being read too high, commonly because its wire is shorted to battery voltage or the pump cell is open.
Common causes
Most likely first.
- Pump current wire shorted to B+
- Open pump cell
- Connector pins corroded - high contact resistance
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
How to diagnose it
- Capture freeze-frame data and compare bank 1 intake-air sensor data with the other bank, if supported, to identify when the high reading appears.
- Inspect the bank 1 sensor connector for corrosion, loose fit, or damaged terminals that could interrupt the pump-current path.
- Check the negative pump-current wire for contact with a power feed, melted insulation, or harness damage near heat sources.
- Following the manufacturer's wiring diagram, test whether the circuit is shorted to battery voltage with the sensor and module isolated as specified.
- If no harness short is found, test the bank 1 sensor pump cell using the manufacturer's procedure to check for an internal open.
Common fixes
- Repair a negative pump-current wire that is touching a battery-voltage feed.
- Restore secure contact at corroded, loose, or damaged connector terminals.
- Repair heat-damaged or otherwise compromised wiring in the bank 1 sensor harness.
- Replace the bank 1 intake-air oxygen sensor if its pump cell is internally open.
Can I keep driving?
A short, gentle drive may be possible if the engine runs normally, but poor intake-side mixture regulation can increase fuel use and emissions. Avoid continued driving if hesitation or rough running 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.