P2221 OBD-II: nox Sensor Heater Sense Circuit
P2221 Severity
Will P2221 go away on its own?
Once the vehicle's onboard system no longer detects the issue, most codes will disappear on their own. If your vehicle still has this code, however, it should be properly diagnosed to avoid a more serious problem.
For a proper diagnosis, RepairPal Certified shops have the equipment, tools, and expertise.
Moderate severity codes might not threaten the vehicle's safety or functionality immediately, but you should still get it diagnosed within a reasonable time frame to keep your car running well.
What causes OBD-II fault code P2221?
Diesel Exhaust Fluid (DEF) is used to assist in converting leftover exhaust particles to harmless gases. In order to burn off those particles, the temperature of the exhaust system needs to increase. the injection of DEF Fluid into the exhaust stream brings Diesel Particulate Filter (DPF) up to temperature. The system is then able to convert harmful NOx to Nitrogen, Carbon Dioxide, and water. The Reductant Catalyst (SRC) was added to further reduce any NOx was still in the exhaust stream. The engine computer (PCM) uses multiple NOx sensors to confirm the performance of the reductant system. If one of the NOx sensors fails to operate properly, code P2221 will be set.
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OBD II Fault Code
- OBD II P2221
OBD-II Code Powertrain Control Module (PCM) failure is defined as a nox Sensor Heater Sense Circuit
Diesel Exhaust Fluid (DEF) is used to assist in converting leftover exhaust particles to harmless gases. In order to burn off those particles, the temperature of the exhaust system needs to increase. the injection of DEF Fluid into the exhaust stream brings Diesel Particulate Filter (DPF) up to temperature. The system is then able to convert harmful NOx to Nitrogen, Carbon Dioxide, and water. The Reductant Catalyst (SRC) was added to further reduce any NOx was still in the exhaust stream. The engine computer (PCM) uses multiple NOx sensors to confirm the performance of the reductant system. If one of the NOx sensors fails to operate properly, code P2221 will be set.
Common Problems That Trigger the P2221 Code
- NOx sensor failure
- Powertrain Control Module (PCM) failure
- Wiring issue
Ask our experts about P2221.
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