Overview
| CODE | REASON | EFFECT |
| Fault Code: 3145 PID: SPN: 4360 FMI: 10/10 LAMP: Amber SRT: |
The SCR catalyst intake temperature sensor is not responding to a change in engine operating conditions.
|
Possible reduced engine performance.
|
Circuit Description
The selective catalytic reduction (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 Location
The SCR intake temperature sensor is located in the aftertreatment system. It is located between the diesel particulate filter and the SCR catalyst in the exhaust system.
Conditions for Running the Diagnostics
This diagnostic runs during active regeneration of the aftertreatment diesel particulate filter.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the SCR catalyst intake temperature was not changing to match engine operating conditions.
Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
- Diesel exhaust fluid injection into the aftertreatment system is disabled.
Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.
Conditions for Clearing the Fault Code
- Ensure the aftertreatment SCR intake temperature is less than 350°C [662°F].
- To validate the repair, start the engine and perform the recommended Cummins® electronic service tool or equivalent Aftertreatment Diesel Particulate Filter Regeneration Test.
- The fault code status displayed by the recommended Cummins® electronic service tool or equivalent will change to INACTIVE immediately after the diagnostic runs and passes.
- The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
- For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
- The “Reset All Faults” command in the recommended Cummins® electronic service tool or equivalent can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.
Shop Talk
Possible causes of this fault code include:
Stuck in-range SCR catalyst intake temperature sensor reading
High resistance in the SCR catalyst intake temperature sensor signal or return lines
Malfunctioning aftertreatment SCR catalyst temperature sensor interface module.
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.
For intermittent power supply and datalink 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.
Troubleshooting Summary
Solution: S00002622
Verification
Conditions
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
Action
- Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.
Specification
Before troubleshooting this fault code, troubleshoot any fault code that is active or has more than one inactive count within the last 25 engine operating hours from the following list:
- Aftertreatment SCR: 3142, 3143
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Solution: S00003260
Verification
Conditions
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
Action
- Run the engine at idle.
- Use the recommended Cummins® electronic service tool or equivalent.
- Monitor the aftertreatment SCR outlet temperature sensor.
- Monitor the aftertreatment SCR intake temperature sensor.
Specification
- A malfunctioning aftertreatment SCR intake temperature sensor has been detected if the aftertreatment SCR intake temperature sensor reading is not within the following specification of the aftertreatment SCR outlet temperature sensor: 23 C [45 F]
Linked Solutions
- None
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the «Conditions for Clearing the Fault Code» found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00002924
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment SCR temperature sensor module from the OEM wiring harness.
- Disconnect the aftertreatment SCR outlet temperature sensor from the aftertreatment SCR temperature sensor module.
- Disconnect the aftertreatment SCR intake temperature sensor from the aftertreatment SCR temperature sensor module.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance of each circuit contained within the aftertreatment SCR temperature sensor module.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- If the resistance is not within specification, then a malfunctioning aftertreatment SCR temperature sensor module has been detected.
Linked Solutions
- None
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the «Conditions for Clearing the Fault Code» found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00003032
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment SCR temperature sensor module from the OEM wiring harness.
- Disconnect the aftertreatment SCR outlet temperature sensor from the aftertreatment SCR temperature sensor module.
- Disconnect the aftertreatment SCR intake temperature sensor from the aftertreatment SCR temperature sensor module.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between aftertreatment SCR intake temperature sensor SIGNAL pin in the aftertreatment SCR temperature sensor module connector to all other pins in the aftertreatment SCR temperature sensor module connector.
- Measure the resistance between aftertreatment SCR outlet temperature sensor SIGNAL pin in the aftertreatment SCR temperature sensor module connector to all other pins in the aftertreatment SCR temperature sensor module connector.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning aftertreatment SCR temperature sensor module has been detected if the resistance is less than the following specification: 100k Ω
Linked Solutions
- None
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the «Conditions for Clearing the Fault Code» found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00000443
Verification
Conditions
- Connect all components.
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
Action
- Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revision listed in the ECM calibration revision history for applicable changes.
Specification
- If a calibration update for this fault code is available, the ECM calibration revision must be that revision or higher.
Linked Solutions
- None
Repair
- Prior to downloading the ECM calibration, check to see that all job images and all other troubleshooting has been documented as downloading an ECM calibration will remove the fault codes on the ECM.
- Download the updated ECM calibration code.
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the «Conditions for Clearing the Fault Code» found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
If all steps have been completed and no root cause has been identified, then follow the technical escalation process.