P2626 - O2 SENSOR PUMPING CURRENT TRIM CIRCUIT / OPEN BANK 1 SENSOR 1

The DTC P2626 OBDII relates to the Oxygen Sensor pump current compensation circuit. This code is set when the PCM detects a malfunction in the O2 Sensor number 1 circuit.

The Oxygen (O2) sensors assist in monitoring the amount of oxygen that is not burned in the exhaust once it comes out of the engine. The PCM (Powertrain Control Module) uses the signals from these sensors to determine the levels of oxygen in the exhaust. These readings are used to adjust the air/fuel mixture.

• Check Engine light ON.
• Reduction of engine power.
• Exhaust emissions increase.
• Higher fuel consumption.

The causes of the P2626 OBD2 fault code are:

• The Oxygen Sensor 1 may be defective.
• The O2 Sensor may have excessive carbon buildup.
• Perhaps the system has a blown fuse.
• Fuel pressure may be excessively high or low.
• The engine may have a vacuum leak.
• Damaged cables or connectors.

To troubleshoot the P2626 OBDII diagnostic code, follow the following steps:

• Check the availability of Technical Service Bulletins (TSB) for your particular vehicle.
• After locating Oxygen Sensor number 1 on bank 1, check its wires and connectors. Verify that none of these are burned, worn, or rubbing against other components. Repair or replace if necessary.
• Check for exhaust leaks while the engine running. Perform fuel pressure tests to ensure that fuel pressure is according to the manufacturer's specifications. Repair if necessary.
• Check the continuity in the Oxygen Sensor These tests should be performed without power to the circuit. You should get 0 ohms. If not, check the condition of the wires.
• Replace the Oxygen Sensor.