P2626 indicates an open circuit in the pumping current trim circuit for the Bank 1 Sensor 1 wideband air-fuel ratio sensor. This circuit is used by the engine control module to precisely control the sensor's internal pump cell, and an open circuit prevents the ECM from properly regulating the sensor's operation.
The sensor's internal pumping current trim circuit is open, which is the most common cause of this code.
A broken wire, damaged insulation, or severed conductor in the harness between the ECM and sensor connector creates an open circuit.
Corrosion, bent pins, or a loose connection at the sensor or ECM connector interrupts the pumping current trim signal.
Internal failure of the ECM's pumping current trim driver for this sensor is possible but rare compared to sensor or wiring faults.
No. P2626 applies to a wideband air-fuel ratio sensor (often called an A/F sensor), which operates differently from a narrowband zirconia oxygen sensor and uses a pumping current trim circuit for precise control.
The vehicle may run poorly, consume more fuel, and emit higher pollutants. Extended driving can risk catalytic converter damage due to incorrect air-fuel mixture control.
ECM failure is a very rare cause of P2626. The code is almost always caused by the sensor itself or its wiring. Replacing the ECM without confirming a driver circuit fault will not resolve the issue.
Yes. An active P2626 will cause a vehicle to fail an OBD-II emissions inspection because the monitor for the air-fuel ratio sensor circuit will not complete or will report a failure.