NOx Sensor Heater Sense Circuit Intermittent Bank 2
P2225 indicates an intermittent problem with the NOx (nitrogen oxide) sensor heater sense circuit on Bank 2. The engine control module detects that the heater circuit voltage signal is dropping in and out, preventing proper sensor operation and accurate emissions monitoring.
What You Might Notice
- Check engine light illuminated
- Reduced fuel economy
- Engine stalling or hesitation
- Rough idle conditions
- Failed emissions test
Most Common Causes
- 1
Faulty NOx sensor heater
The heater element within the NOx sensor Bank 2 is failing or has intermittent internal resistance, causing the sense circuit voltage to fluctuate.
- 2
Corroded or loose connector
The NOx sensor connector on Bank 2 has corrosion, water intrusion, or loose pins creating intermittent electrical contact.
- 3
Wiring harness damage
The sensor wiring between the NOx sensor and ECM has breaks, fraying, or shorts that cause intermittent signal loss.
- 4
ECM power relay or fuse issue
A faulty relay or blown fuse in the sensor heater circuit causes intermittent power supply to the NOx sensor heater.
How to Diagnose It
- 1
Check Faulty NOx sensor heater — The heater element within the NOx sensor Bank 2 is failing or has intermittent internal resistance, causing the sense circuit voltage to fluctuate.
- 2
Check Corroded or loose connector — The NOx sensor connector on Bank 2 has corrosion, water intrusion, or loose pins creating intermittent electrical contact.
- 3
Check Wiring harness damage — The sensor wiring between the NOx sensor and ECM has breaks, fraying, or shorts that cause intermittent signal loss.
- 4
Check ECM power relay or fuse issue — A faulty relay or blown fuse in the sensor heater circuit causes intermittent power supply to the NOx sensor heater.
How to Fix It
- 1
Replace NOx sensor Bank 2
Remove and replace the faulty NOx sensor on Bank 2 with an OEM or quality replacement unit, then clear the code and test.
- 2
Inspect and repair connectors
Disconnect the NOx sensor connector on Bank 2, clean corrosion with electrical contact cleaner, check for bent pins, and reconnect firmly.
- 3
Check and repair wiring harness
Inspect the NOx sensor wiring harness between Bank 2 sensor and ECM for damage, loose connections, or shorts; repair or replace damaged sections.
- 4
Test heater circuit power supply
Verify the heater relay and fuse for the NOx sensor circuit are functioning; replace faulty relay or blown fuse to restore power.
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