Circuit DescriptionThe selective catalytic reduction (SCR) outlet temperature sensor is used by the engine control module (ECM) to monitor the engine exhaust temperature exiting the SCR catalyst. The ECM monitors the voltage on the signal pin and converts this to a temperature value.

Component LocationThe SCR outlet temperature sensor is located in the aftertreatment system. The sensor is located after the SCR catalyst.

Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault CodesThe Engine Control Module (ECM) detected the temperature at the SCR catalyst outlet temperature sensor was greater than 700?C [1292?F] for more than 60 seconds.

Action Taken When the Fault Code is ActiveThe ECM illuminates the red STOP ENGINE lamp immediately after the diagnostic runs and fails.The engine will be shut down if the Engine Protection Shutdown feature is enabled.Diesel exhaust fluid injection into the aftertreatment system is disabled.Conditions for Clearing the Fault CodeTo validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.The ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and passes.The Reset All Faults command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop TalkThis fault will go inactive immediately after the SCR outlet temperature drops below the warning limit, and will likely be inactive at the time of diagnosis. For these reasons this troubleshooting tree must be used for both active and inactive fault codes.

Possible causes of this fault code include:

Malfunctioning SCR catalystDegraded, diluted, or incorrect diesel exhuast fluidMalfunctioning in-range SCR outlet temperature sensor.Reference the appropriate original equipment manufacturer (OEM) wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

For intermittent power supply and data link communication issues with aftertreatment components, it is highly recommended that the OEM power distribution center fuses and relays be thoroughly checked for loose, missing, or intermittent connections.

Possible Cause:1) ECM Calibration