Circuit DescriptionThe SCR intake temperature sensor is used by the engine control module (ECM) to monitor the engine exhaust temperature entering the SCR catalyst. The ECM monitors the voltage on the SIGNAL pin and converts this to a temperature value.

Component LocationThe SCR intake temperature sensor is located in the aftertreatment system. The sensor is located between the diesel particulate filter and the SCR catalyst in the exhaust system.

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

Conditions for Setting the Fault CodesThe ECM detects that the temperature at the SCR catalyst intake is greater than a calibratible value.

Action Taken When the Fault Code is ActiveThe ECM logs the fault code immediately when the diagnostic runs and fails.Conditions for Clearing the Fault CodeTo validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop-and-go city driving and steady state highway driving. It may be necessary to load the unit for certain diagnostics in the ECM to run.To validate the repair using a Chassis Dynamometer Test, utilize a routine that incorporates acceleration and motoring events, steady state highway operation, and load. This will simulate normal driving and allow the diagnostics in the ECM to run.The fault code status displayed by INSITE? electronic service tool will change to INACTIVE 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.

Shop TalkThis fault will go inactive immediately after the SCR intake temperature drops below the warning limit, and will likely be inactive when the vehicle is in the shop. For these reasons this troubleshooting tree must be used for both active and inactive fault codes.

Possible causes of this fault code include:

Degraded, diluted, or incorrect diesel exhaust fluidMalfunctioning in-range SCR intake temperature sensorUpstream exhaust system malfunction.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