P2209

P2209-NOx SENSOR HEATER CIRCUIT PERFORMANCE - BANK 1 SENSOR 1




For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation

The aftertreatment system is equipped with two Nox Sensors and modules. The upstream NOx Sensor 1/1 is located before the SCR Catalyst and is permanently connected to a corresponding Nox Sensor Module mounted on the right frame rail. The downstream NOx Sensor 1/2 is located at the outlet of the SCR Catalyst and is permanently connected to a corresponding Nox Sensor Module also mounted on the right frame rail. The NOx Sensors and NOx Sensor Modules are calibrated to each other and must be replaced as an assembly. The two NOx Sensor and Module assemblies are not interchangeable. The NOx Sensor Modules are smart devices and communicate with the Powertrain Control Module (PCM) over the J1939 Data Link. The NOx Sensor Modules perform their own internal diagnostics and report malfunctions back to the PCM. The NOx Sensors are used to monitor the efficiency of the SCR Catalyst and dosing system. The PCM will illuminate the MIL lamp immediately after the monitor runs and fails. The PCM will turn off the MIL Lamp after the monitor runs and passes for three consecutive trips.

- When Monitored:
When the engine is running and the exhaust temperature at NOx Sensor 1/1 is above 150°C (302°F).

- Set Condition:
The Powertrain Control Module detects that the NOx Sensor heater is unable to maintain its normal operating temperature.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool check for active DTCs.

Is the DTC active?

Yes

- Replace the NOx Sensor 1/1. . Bank 1 Sensor 1
NOTE: If DTCs P2202, P220A, or U029D are present, perform the diagnostic for those DTCs before replacing the Nox Sensor.

No

- Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. Intermittent Condition Test.