What it means
The oxygen sensor pumping current trim circuit for bank 1 sensor 1 is open or has an open-circuit fault.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The upstream air-fuel sensor on bank 1, sensor 1, measures oxygen in the exhaust before the catalytic converter; its pumping-current trim circuit helps the module interpret that sensor's signal. P2626 is set when the trim circuit for this specific sensor is open, so the module may be unable to make accurate fuel-mixture corrections. Bank 1 is the side containing cylinder 1.
Common causes
Most likely first.
- Trim wire open
- Internal sensor fault
- 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 fuel-trim and oxygen-sensor data to see how bank 1 sensor 1 behaves when the fault is present.
- Locate bank 1 sensor 1 ahead of the catalytic converter and inspect its connector and harness for heat damage, strain, or an unplugged connection.
- Check the connector for a pushed-back terminal and confirm the trim-circuit wire is not broken near the plug or exhaust.
- With the correct wiring diagram, test continuity through the trim circuit from the sensor connector toward the module.
- Check the sensor's internal trim circuit using the manufacturer's procedure to distinguish an open inside the sensor from an open in the harness.
- After repair, clear the code and confirm bank 1 sensor 1 data and fuel trims respond normally during a drive cycle.
Common fixes
- Reconnect the bank 1 sensor 1 plug securely.
- Repair a broken trim-circuit wire or pushed-back terminal.
- Replace heat-damaged wiring and secure it away from the exhaust.
- Replace bank 1 sensor 1 if its internal trim circuit is open.
Can I keep driving?
You can usually drive gently if the engine runs smoothly, but fuel economy and emissions control may suffer and the vehicle may fail an emissions test. Avoid extended driving if it begins to hesitate or run roughly.
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.