NOx Sensor Circuit Low Bank 1
The P2202 code indicates that the Engine Control Module (ECM) has detected a low voltage or current condition in the NOx sensor circuit for Bank 1. This sensor monitors nitrogen oxide levels in the exhaust to optimize diesel exhaust fluid (DEF) injection and reduce emissions. A low circuit condition can be caused by a faulty sensor, wiring issues, or a problem with the ECM. This code is common in modern diesel vehicles and can lead to increased emissions and potential drivability issues.
01. Most Common Causes
- Faulty NOx sensor
- Damaged or corroded wiring/connectors
- Exhaust leak near the sensor
- Faulty ECM
02. Symptoms You Will Notice
- Check Engine Light on
- Reduced fuel economy
- Failed emissions test
- Possible reduced engine power
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for related codes.
Step 2: Visually inspect the NOx sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor's voltage and resistance with a multimeter and compare to manufacturer specs.
Step 4: Check for exhaust leaks near the sensor that could affect readings.
Step 5: If all else is fine, replace the NOx sensor and clear the code.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
You can drive short distances, but it may cause increased emissions and reduced fuel economy. Prolonged driving could lead to more serious issues or failed emissions tests.
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.