O2 Sensor Negative Current Control Circuit Low Bank 2 Sensor 1
The P2255 code indicates that the powertrain control module (PCM) has detected a low voltage or current condition in the negative current control circuit of the oxygen sensor located on Bank 2, Sensor 1 (upstream of the catalytic converter). This circuit is responsible for regulating the sensor's heater and bias voltage. A low signal suggests a short to ground, open circuit, or a faulty sensor, which can affect air-fuel ratio monitoring and emissions.
01. Most Common Causes
- Faulty oxygen sensor (Bank 2 Sensor 1)
- Open or shorted wiring in the sensor circuit
- Corroded or damaged connector
- Blown fuse or relay for the O2 sensor heater
- PCM failure (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor fuel economy
- Rough idle or hesitation
- Failed emissions test
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the O2 sensor wiring and connector for damage, corrosion, or loose connections.
Step 3: Using a multimeter, check the sensor's heater circuit resistance (typically 2-10 ohms) and compare to specs.
Step 4: Test the negative current control circuit for voltage (should be near 0V when active) and continuity to ground.
Step 5: If wiring is intact, replace the oxygen sensor (Bank 2 Sensor 1).
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
You can drive short distances, but it may cause poor fuel economy and increased emissions. Prolonged driving could damage the catalytic converter.
How much does it cost to fix?▼
Typically $50-$150 for a DIY sensor replacement, or $150-$300 at a shop including labor.