NOx Sensor Heater Control Circuit Low Bank 1
The P2206 code indicates that the powertrain control module (PCM) has detected a low voltage condition in the heater control circuit of the nitrogen oxide (NOx) sensor on Bank 1. 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, especially during cold starts. A low circuit condition typically means the voltage is below the expected threshold, which can be caused by a faulty sensor, wiring issues, or a blown fuse.
01. Most Common Causes
- Faulty NOx sensor (Bank 1)
- Open or shorted heater circuit wiring
- Blown fuse or relay for NOx sensor heater
- Corroded or loose connector at the sensor
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Increased emissions
- Possible failed emissions test
- Reduced fuel economy (in some cases)
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes (e.g., P2201, P2202).
Step 2: Visually inspect the NOx sensor connector and wiring for damage, corrosion, or loose connections.
Step 3: Test the heater circuit voltage at the sensor connector with a multimeter (should be battery voltage with key on).
Step 4: Check the fuse and relay for the NOx sensor heater circuit.
Step 5: If voltage is present and wiring is intact, replace the NOx sensor.
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 tests and the SCR system may not function properly, potentially leading to reduced performance or limp mode. 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 costs $100-$300, and labor adds $100-$300 depending on the vehicle.