NOx Sensor Circuit (Bank 1)
What does P2200 mean?
The P2200 code means the vehicle's onboard diagnostic system has detected: NOx Sensor Circuit (Bank 1). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Failed emissions test
- Possible reduced power in limp mode
- Increased NOx emissions
- SCR system warning light
Probable Causes (Ranked by Likelihood)
- Failed NOx sensor on Bank 1 Very High
- Damaged wiring or connector to the NOx sensor High
- NOx sensor heater circuit failure Moderate
- ECM communication fault with the NOx sensor module Moderate
- Contaminated NOx sensor from coolant or oil intrusion Low
Step-by-Step Diagnostic Procedure
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Read freeze frame data and check NOx sensor values with a scan tool
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Inspect NOx sensor wiring harness and connector for damage or corrosion
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Test NOx sensor heater circuit resistance
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Check for CAN bus communication errors between the sensor module and ECM
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If diesel, verify DEF quality and SCR system operation
Frequently Asked Questions
What is a NOx sensor?
A NOx sensor measures the level of nitrogen oxides in the exhaust. It is used primarily in diesel vehicles with SCR (selective catalytic reduction) systems to monitor and control emissions.
Are NOx sensors expensive to replace?
Yes, NOx sensors are typically $200 to $500 for the part alone and require proper scan tool calibration after replacement, adding to the overall cost.
Can I drive with a bad NOx sensor?
You can usually drive, but the vehicle may enter a reduced power mode, will fail emissions testing, and the SCR system cannot optimize properly, which increases harmful emissions.