NOx Sensor Heater Control Circuit Low Bank 2
The P2219 code indicates that the powertrain control module (PCM) has detected a low voltage or resistance in the heater control circuit of the nitrogen oxide (NOx) sensor on Bank 2. This sensor is typically located downstream of the selective catalytic reduction (SCR) system and is used to monitor NOx levels for emissions control. A low circuit condition can be caused by a faulty sensor, damaged wiring, or a poor electrical connection, leading to improper heater operation and potential emissions issues.
1. Most Common Causes
- Faulty NOx sensor (Bank 2)
- Open or shorted heater circuit wiring
- Corroded or loose connector at the sensor
- Blown fuse or relay for the NOx sensor heater
- Failed PCM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Increased emissions
- Possible failed emissions test
- Reduced fuel economy (in some cases)
- No noticeable drivability issues
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all stored codes and freeze frame data.
Step 2: Visually inspect the NOx sensor connector and wiring for damage, corrosion, or loose connections.
Step 3: Measure the heater circuit resistance at the sensor connector (typically 2-10 ohms). Compare to manufacturer specs.
Step 4: Check for battery voltage and ground at the heater circuit with the ignition on.
Step 5: If voltage and ground are present but resistance is out of spec, replace the NOx sensor. If no voltage, check fuses and relays.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, the vehicle is generally safe to drive, but it may fail an emissions test and could cause increased emissions. It's best to address the issue promptly.
How much does it cost to fix?▼
The cost typically ranges from $200 to $600, including parts and labor. The NOx sensor itself can cost $100-$300, and labor adds $100-$300 depending on the vehicle.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.