Overview
| CODE | REASON | EFFECT |
| Fault Code: 1993 PID: SPN: 4795 FMI: 11/31 LAMP: Amber SRT: |
The aftertreatment diesel particulate filter in the exhaust system is not present.
|
Possible reduced engine performance. |
Circuit Description
The engine aftertreatment system monitors the soot load in the aftertreatment diesel particulate filter. Under normal operating conditions, the aftertreatment diesel particulate filter is self-cleaning, where soot is converted to carbon dioxide, nitrogen, and water. Under light load operating conditions, it can be necessary to perform a stationary regeneration of the aftertreatment diesel particulate filter. The soot load in the aftertreatment diesel particulate filter is estimated, using the aftertreatment differential pressure sensor and the calculated soot output of the engine.
Component Location
The aftertreatment diesel particulate filter is located in the exhaust system and is installed by the original equipment manufacturer (OEM). Refer to the OEM service manual.
Conditions for Running the Diagnostics
This diagnostic runs when the engine is running and exhaust flow is above a minimum level.
Conditions for Setting the Fault Codes
The aftertreatment diesel particulate filter differential pressure was below a calibratiable value when the exhaust flow rate was above a calibratiable value.
Action Taken When the Fault Code is Active
- The ECM will illuminate the amber CHECK ENGINE lamp immediately after the diagnostic runs and fails on two consecutive trips.
Active and stationary regeneration of the diesel particulate filter will be disabled.
Exhaust gas recirculation (EGR) valve operation will be 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
- To validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop and go city type driving and steady state highway type 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, utilize a routine that incorporates acceleration and motoring events, steady state highway type operation, and load. This will simulate normal driving and allow the diagnostics in the ECM to run.
- 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.
- 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:
The aftertreatment diesel particulate filter has been removed from the vehicle
The aftertreatment diesel particulate filter is cracked or broken
The aftertreatment diesel particulate filter differential tubes are installed incorrectly, broken, loose, or have been tampered with
The aftertreatment diesel particulate filter differential tubes are installed backwards.
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: S00000763
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 differential pressure: 1879, 1881, 1883
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Solution: S00010099
Verification
Conditions
- Turn keyswitch OFF.
Action
- Visually inspect the aftertreatment differential pressure tubes for proper installation.
- Inspect the aftertreatment DPF differential pressure sensor tubes for signs of damage, plugging, kinks, leakage or loose connections.
In extreme cold ambient temperatures it is important to check for a frozen, plugged, or restricted aftertreatment DPF differential pressure sensor tubes. Ice can form in the aftertreatment DPF differential pressure sensor tubes causing obstruction/sticking and may not be present at the time of troubleshooting.
Specification
- If damage, kinks or blockages are found, then proceed to the Repair section.
Linked Solutions
- None
Validation
- 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.
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- 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.
Solution: S00000793
Verification
Conditions
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
Action
- Use the recommended Cummins® electronic service tool or equivalent.
- Monitor the aftertreatment DPF differential pressure sensor voltage.
Specification
- If the aftertreatment DPF differential pressure sensor voltage readings are not within specification, then a malfunctioning aftertreatment DPF differential pressure sensor 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: S00011013
Verification
Conditions
- Turn keyswitch OFF.
Specification
- If a leak is found, then proceed to the Repair section.
Linked Solutions
- None
Repair
- Repair or replace the leaking components.
Refer to OEM Service Manual
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: 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 diesel oxidation catalyst intake connection.
- Visually inspect the exhaust piping for leaks, cracks, and loose connections.
- Visually inspect for leaks at the aftertreatment diesel oxidation catalyst housing, sensor ports and connection points.
- Visually inspect the aftertreatment and selective catalytic reduction 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 the aftertreatment diesel oxidation catalyst.
- Replace the aftertreatment diesel particulate filter.
- Replace the aftertreatment selective catalytic reduction 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: S00009931
Verification
Conditions
- Turn keyswitch OFF.
Specification
- If a leak is found, then proceed to the Repair section.
Linked Solutions
- None
Repair
Repair or replace only the components that were found to be out of specification.
- Repair or replace the charge air cooler.
- Repair or replace the charge air cooler hoses.
Refer to OEM Service Manual
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.