O2 Sensor Positive Current Control Circuit High Bank 1 Sensor 1
The P2239 code indicates that the Powertrain Control Module (PCM) has detected a high voltage or current in the positive current control circuit of the oxygen sensor (O2 sensor) located before the catalytic converter on Bank 1. This circuit is responsible for regulating the sensor's heater and pump current. A high reading suggests a short to voltage, open circuit, or a faulty sensor, which can affect air-fuel ratio monitoring and emissions.
01. Most Common Causes
- Faulty oxygen sensor (Bank 1 Sensor 1)
- Short to voltage in the O2 sensor wiring or connector
- Open circuit in the positive current control circuit
- Corroded or damaged O2 sensor connector
- Failed PCM (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: Use an OBD2 scanner to confirm the code and check for other related codes.
Step 2: Visually inspect the O2 sensor wiring and connector for damage, corrosion, or shorts.
Step 3: Test the O2 sensor's heater circuit and signal voltage using a multimeter.
Step 4: Check for proper voltage at the sensor connector (typically 12V on the heater circuit).
Step 5: If wiring and voltage are okay, replace the O2 sensor (Bank 1 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?▼
The cost typically ranges from $150 to $400, including parts and labor. The sensor itself costs $50-$150, and labor adds $100-$250.