The P2255: O2 Sensor Negative Current Control Circuit Low Bank 2 Sensor 1 code refers to an issue where the voltage in the negative current control circuit of the oxygen (O2) sensor for Bank 2 Sensor 1 is lower than the expected value. This can prevent the sensor from operating correctly and accurately measuring the oxygen content in the exhaust gases, leading to incorrect air-fuel mixture adjustments. This issue could stem from a faulty sensor, damaged wiring, or connector problems.
P2255 – Quick Overview
Code | Information |
---|---|
Meaning | P2255: O2 Sensor Negative Current Control Circuit Low Bank 2 Sensor 1 |
Is it serious? | Yes, as low voltage can prevent the O2 sensor from accurately measuring oxygen levels, which affects fuel efficiency and emissions. |
Possible causes | – Low voltage in O2 sensor negative current control circuit for Bank 2 Sensor 1 – Faulty O2 sensor – Wiring issues – Connector problems |
How to diagnose? | – Measure voltage in the O2 sensor negative current control circuit for Bank 2 Sensor 1 – Test the sensor for proper operation – Inspect wiring and connectors for faults |
P2255 Meaning
The P2255: O2 Sensor Negative Current Control Circuit Low Bank 2 Sensor 1 code indicates that the negative current control circuit for the O2 sensor in Bank 2 Sensor 1 is reading a voltage that is too low. The negative current control circuit is essential for the sensor to accurately monitor the oxygen levels in the exhaust gases. A low voltage condition can distort the sensor’s output, leading to improper air-fuel mixture adjustments, which can ultimately impact engine performance and emissions.
Step-by-step diagnostic guide
Action | Description | Tools Needed |
---|---|---|
Check for Other Codes | Use an OBD-II scanner to determine if there are additional related codes present. The presence of other codes may indicate a broader issue affecting the circuit. | OBD-II Scanner |
Measure Voltage in the O2 Sensor Negative Current Control Circuit | Use a multimeter to measure the voltage in the negative current control circuit for Bank 2 Sensor 1. Compare the reading against the manufacturer’s specifications. A voltage that is lower than expected could indicate an issue with wiring or a malfunctioning sensor. | Multimeter, Vehicle Service Manual |
Test the Sensor for Proper Operation | Use a diagnostic scanner to test the O2 sensor. Verify if the sensor is functioning correctly under different conditions. If the sensor is faulty or shows incorrect response characteristics, it may need to be replaced. | Diagnostic Scanner, Multimeter |
Inspect Wiring and Connectors for Faults | Visually inspect the wiring and connectors for Bank 2 Sensor 1. Look for signs of damage, such as frayed or broken wires, melted insulation, or loose connections that could cause a drop in voltage. Repair or replace any damaged components as needed. | Flashlight, Safety Gloves |
Check the Sensor Connector Condition | Carefully inspect the sensor connector for any signs of corrosion, bent pins, or poor fit. A loose or corroded connection can lead to low voltage conditions. Ensure that the connector is properly seated and in good condition. | Flashlight |
Clear the Code and Test Drive | After repairing any faults, use an OBD-II scanner to clear the fault code. Conduct a test drive to monitor the sensor’s performance and confirm that the negative current control voltage has returned to the expected range. | OBD-II Scanner, Vehicle Owner’s Manual |
Recheck for Codes | After the test drive, re-scan the vehicle to verify that the P2255 code has not returned. If the code persists, further diagnostics will be necessary to identify any underlying problems in the circuit or the sensor itself. | OBD-II Scanner |

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Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)