Overview
| CODE | REASON | EFFECT |
| Fault Code: 7224 PID: SPN: 7332 FMI: 1/18 LAMP: Amber SRT: |
The ECM detected a failure of the engine system to achieve and/or maintain DEF dosing temperature conditions while operating in SCR Thermal Management.
|
None on performance. |
Circuit Description
SCR Thermal Management (TM) is used to achieve or maintain the SCR at a minimum operating temperature to allow for efficient NOx conversion. This is done by increasing the exhaust temperature of the engine.
Component Location
The SCR catalyst is located in the vehicle’s exhaust system, after the diesel particulate filter and decomposition tube.
Conditions for Running the Diagnostics
This diagnostic consists of two parts. The first part of this diagnostic runs at initial key ON and the second part runs when the engine is running.
Conditions for Setting the Fault Codes
The Engine failed to achieve and/or maintain DEF dosing temperature conditions while operating in SCR Thermal Management mode.
Action Taken When the Fault Code is Active
- The ECM illuminates the amber CHECK ENGINE lamp and/or malfunction indicator lamp (MIL) after the diagnostic fails on two consecutive trips.
Conditions for Clearing the Fault Code
- It is necessary to use the “Reset All Faults” command in the recommended Cummins® electronic service tool or equivalent to clear this fault and extinguish the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL).
Shop Talk
Possible causes of this fault code include:
- Fuel system malfunction
A malfunctioning variable geometry turbocharger (VGT)
High exhaust restriction
- Leaks in the exhaust system
A malfunction of the exhaust gas recirculation (EGR) valve
Soot plugging the front face of the aftertreatment diesel oxidation catalyst
Build up or plugging on the inlet face of the Diesel Particulate Filter.
Troubleshooting Summary
Solution: S00005660
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:
- Fuel: 559, 1139, 1141, 1142, 1143, 1144, 1145
- Intake manifold: 125, 2973
- EGR: 1228, 1896, 1898, 2198, 2272, 2349, 2353, 2357, 2387, 2449, 2634, 2635, 2636, 2961, 2962, 3136, 3137, 3138, 3342, 3382, 3383
- EGR differential pressure: 1866, 2273, 2274
- Aftertreatment SCR: 3142, 3146, 3147, 3148, 3165, 4164, 4165, 4166, 4518, 4519, 4521, 4524, 4525, 6266, 6267, 6268
- Aftertreatment DOC: 3313, 3314, 3315, 1664, 1691, 2638, 4282
- Aftertreatment DPF: 3316, 3317, 3318, 3319, 3321, 3322, 1921, 1922, 1981, 2639
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Solution: S00001008
Verification
Conditions
- Engine running.
Action
- Visually inspect for leaks in the exhaust manifold to head.
- Visually inspect for leaks from the turbocharger to exhaust manifold.
- Visually inspect for leaks in the exhaust plumbing between the turbocharger outlet and the Aftertreatment DOC intake connection.
- Visually inspect the exhaust piping for leaks, cracks, and loose connections.
- Inspect for leaks at the aftertreatment DOC housing, sensor ports and connection points.
- Visually inspect the aftertreatment and SCR components for exhaust leaks.
Specification
- If there is any damage or leaks found in the exhaust system, then proceed to the Repair section.
Linked Solutions
- None
Repair
Repair or replace only the components that were found to be out of specification.
- Replace the exhaust manifold.
- Repair or replace the exhaust plumbing.
Refer to OEM Service Manual
- Replace aftertreatment DOC.
- Replace the aftertreatment diesel particulate filter.
- Replace the aftertreatment SCR Catalyst.
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.