NOx Sensor Heater Circuit Low Bank 2
The P2223 code indicates that the powertrain control module (PCM) has detected a low voltage condition in the heater circuit of the nitrogen oxide (NOx) sensor on Bank 2. The NOx sensor heater is essential for bringing the sensor up to operating temperature quickly, especially during cold starts. A low voltage reading suggests a short to ground, open circuit, or a faulty sensor, which can prevent the sensor from functioning correctly and may lead to inaccurate emissions readings.
01. Most Common Causes
- Faulty NOx sensor (Bank 2)
- Open or shorted heater circuit wiring
- Blown fuse or relay for NOx sensor heater
- Corroded or damaged connector at the sensor
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Possible reduced fuel economy
- Possible engine performance issues
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the NOx sensor connector and wiring for damage, corrosion, or loose connections.
Step 3: Using a multimeter, check the heater circuit resistance at the sensor connector (typically 2-10 ohms).
Step 4: Check for battery voltage and ground at the sensor connector with the ignition on.
Step 5: If voltage and ground are present but resistance is out of spec, replace the NOx sensor.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but the vehicle may fail an emissions test and could experience reduced fuel economy. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
The cost typically ranges from $200 to $600, including parts and labor, depending on the vehicle and whether the sensor or wiring needs replacement.