NOx Sensor Heater Control Circuit High Bank 2
The P2220 code indicates that the powertrain control module (PCM) has detected a high voltage condition in the heater control circuit of the nitrogen oxide (NOx) sensor for Bank 2. This sensor is part of the selective catalytic reduction (SCR) system used to reduce NOx emissions. The heater is essential for the sensor to reach operating temperature quickly. A high voltage reading suggests a short to power, a faulty sensor, or a wiring issue.
01. Most Common Causes
- Faulty NOx sensor (Bank 2)
- Short to voltage in the heater control circuit
- Damaged wiring or connector
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light on
- Increased NOx emissions
- Possible failed emissions test
- Reduced fuel economy (in some cases)
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Visually inspect the NOx sensor wiring and connector for damage, corrosion, or loose pins.
Step 3: Measure voltage at the heater control circuit; compare to manufacturer specs (typically 12V with engine running).
Step 4: Test the NOx sensor heater resistance; if out of range, replace the sensor.
Step 5: If wiring and sensor are OK, check for PCM issues or software updates.
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 fuel economy could be affected. It's best to repair promptly.
How much does it cost to fix?▼
Typically $200-$600, including parts (NOx sensor) and labor. Diagnosis may add $100-$150.