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 on Bank 2. This sensor is part of the selective catalytic reduction (SCR) system used to reduce emissions. The heater is essential for the sensor to reach operating temperature quickly. A high voltage reading suggests a short to power, open circuit, or faulty sensor, which can prevent accurate NOx readings and affect emission control.
1. Most Common Causes
- Faulty NOx sensor (Bank 2)
- Short to power in the heater control circuit
- Open or damaged wiring/connector
- Failed PCM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Increased emissions
- Possible reduced engine performance
- Failed emissions test
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P2220 and check for related codes.
Step 2: Visually inspect the NOx sensor wiring and connector for damage, corrosion, or shorts.
Step 3: Measure voltage at the heater control circuit; compare to manufacturer specs.
Step 4: Test the NOx sensor heater resistance; replace if out of range.
Step 5: If wiring and sensor are okay, check PCM for faults.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
You can drive short distances, but the vehicle may fail emissions and could enter limp mode. It's best to repair promptly.
How much does it cost to fix?▼
Typically $200-$600 including parts and labor, depending on the sensor cost and labor rates.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.