P2215NOx Sensor Circuit Low Input (Bank 2)
The Bank 2 NOx sensor signal circuit is reading below its expected voltage range, indicating a short to ground or a failed sensor.
Definition
On engines with two exhaust banks (or two NOx sensor positions mapped as banks), the control module monitors the Bank 2 NOx sensor to manage SCR dosing and verify NOx reduction. P2215 sets when the Bank 2 sensor's signal circuit stays below the minimum plausible threshold because of a short to ground, wiring damage, or an internal sensor failure. The MIL illuminates, NOx-based closed-loop control is degraded, and on diesel applications a persistent fault can trigger SCR inducement torque or speed derate and an emissions-test failure.
Common causes
- Failed NOx sensor (element or integrated module)
- Signal or CAN wiring shorted to ground
- Corroded or water-contaminated connector
- Poor sensor module ground or supply circuit
- Soot or moisture damage to the sensing element from exhaust condensation
Common misdiagnoses
- SCR catalyst
- DEF injector or pump
- Bank 1 NOx sensor replaced instead of Bank 2
- Oxygen/air-fuel sensor
Troubleshooting steps
1.Identify the correct sensor location
Confirm from service information which physical sensor is Bank 2 (or sensor position 2) on this application before replacing anything.
2.Compare Bank 1 and Bank 2 NOx data
At a steady cruise both sensors should report plausible, changing ppm values; a flatlined or zero Bank 2 reading confirms the circuit fault.
3.Inspect harness and connector
Trace the Bank 2 sensor harness for chafing at the frame rail and check the connector for corrosion and moisture.
4.Verify power and ground at the sensor module
Confirm battery voltage on the supply and less than 0.1 V drop on the ground at the sensor connector, key on.
5.Replace the sensor if circuits test good
Install an OE-calibrated NOx sensor, clear codes, and run the SCR/NOx monitor drive cycle to confirm the repair.