O2 Sensor Negative Current Control Circuit Low Bank 2 Sensor 1
P2255 indicates the PCM detected an issue with the negative current control circuit of the Bank 2 Sensor 1 oxygen sensor. This sensor monitors exhaust oxygen levels to help the engine run efficiently, and a fault in its negative current control circuit prevents proper voltage signal output.
What You Might Notice
- Check Engine Light illuminated
- Reduced fuel economy
- Diminished engine performance or power loss
- Rough idle or hesitation during acceleration
- Stored lean or rich exhaust codes alongside this code
Most Common Causes
- 1
Defective Bank 2 Sensor 1 Oxygen Sensor
The O2 sensor itself has failed internally or developed a fault in its negative current control circuitry, preventing it from accurately reporting exhaust oxygen levels to the PCM.
- 2
Damaged Wiring or Connector at O2 Sensor
Corrosion, breaks, or loose connections in the wiring harness or sensor connector disrupt the negative current control signal path between the sensor and PCM.
- 3
PCM or Control Module Fault
A malfunctioning Powertrain Control Module may fail to properly control or read the negative current circuit of the O2 sensor, though this is less common than sensor failures.
- 4
Internal Engine Issues Affecting Sensor
Exhaust system leaks or excessive carbon buildup upstream of the sensor can cause the sensor to receive false oxygen readings and trigger the negative current control fault.
How to Diagnose It
- 1
Check Defective Bank 2 Sensor 1 Oxygen Sensor — The O2 sensor itself has failed internally or developed a fault in its negative current control circuitry, preventing it from accurately reporting exhaust oxygen levels to the PCM.
- 2
Check Damaged Wiring or Connector at O2 Sensor — Corrosion, breaks, or loose connections in the wiring harness or sensor connector disrupt the negative current control signal path between the sensor and PCM.
- 3
Check PCM or Control Module Fault — A malfunctioning Powertrain Control Module may fail to properly control or read the negative current circuit of the O2 sensor, though this is less common than sensor failures.
- 4
Check Internal Engine Issues Affecting Sensor — Exhaust system leaks or excessive carbon buildup upstream of the sensor can cause the sensor to receive false oxygen readings and trigger the negative current control fault.
How to Fix It
- 1
Replace Bank 2 Sensor 1 Oxygen Sensor
Remove the faulty oxygen sensor from the exhaust manifold or exhaust pipe on Bank 2 and install a new OEM or quality replacement sensor. Ensure proper torque and reconnect the electrical connector securely.
- 2
Inspect and Repair Wiring and Connectors
Check the entire wiring harness from the oxygen sensor to the PCM for corrosion, damage, or loose connections. Repair or replace any damaged wire sections and clean corroded connectors thoroughly.
- 3
Inspect Exhaust System for Leaks
Examine the exhaust manifold, gaskets, and exhaust pipes on Bank 2 for cracks or leaks that could introduce false oxygen readings. Reseal or replace any leaking components.
- 4
Clear Code and Perform Retest
After repairs, clear the DTC using a diagnostic scanner and test drive the vehicle to verify the code does not return and engine performance has improved.
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