NOx sensor heater sense circuit bank 1 sensor 1

The circuit the NOx sensor module uses to monitor the sensor heater has a fault. NOx sensor 1 is usually the one before the AdBlue catalyst. NOx sensors measure exhaust nitrogen oxides for emissions control and monitoring, including SCR or NOx-storage systems. The probe and its control module normally form a matched assembly. On vehicles with SCR, a confirmed unresolved fault may trigger reduced performance or a no-restart countdown; follow the displayed warning and the vehicle handbook.

• engine warning light and/or AdBlue/emissions warning
• possibly a no-start countdown
• usually no change in how the car drives

1. 01Read all NOx/SCR codes and NOx sensor live data (sensor ready status and values).
2. 02Check the sensor module's fuse, power supply and ground.
3. 03Inspect the connector and wiring along the exhaust for heat damage and water ingress.
4. 04Check for exhaust leaks near the sensor.
5. 05Replace the correctly identified probe/module assembly only if the diagnostic tests confirm an internal sensor fault; use the specified compatible part.
6. 06After repair, perform any required sensor initialization or adaptation, clear repairable faults, and complete the OEM validation drive cycle.