NOx Sensor Heater Circuit High Bank 2
The P2224 code indicates that the powertrain control module (PCM) has detected a high voltage condition in the heater circuit of the nitrogen oxide (NOx) sensor on Bank 2 (the side of the engine not containing cylinder #1). The NOx sensor heater is essential for quickly bringing the sensor to operating temperature to accurately measure NOx emissions. A high voltage reading suggests a short to power, a faulty sensor, or a wiring issue, which can lead to incorrect emissions readings and potential drivability problems.
01. Most Common Causes
- Faulty NOx sensor (Bank 2)
- Short to voltage in the heater circuit wiring
- Damaged connector or corroded terminals
- Blown fuse or relay for the NOx sensor heater
- PCM internal failure (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Possible reduced fuel economy
- Possible hesitation or rough idle (in severe 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 connector and wiring for damage, corrosion, or shorts.
Step 3: Measure voltage at the heater circuit with a multimeter; compare to manufacturer specifications.
Step 4: Check the NOx sensor heater resistance; replace if out of range.
Step 5: Inspect related fuses and relays; replace if blown.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
You can drive short distances, but the vehicle may fail emissions 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 (NOx sensor) and labor. Sensor replacement is the most common fix.