Cummins ISB6.7 CM2350 (2013-17) Fault Code: 1993 PID: SPN: 4795 FMI: 31 Aftertreatment Diesel Particulate Filter Missing- Condition Exists
Cummins ISB6.7 CM2350 (2013-17) Fault Code: 1993 PID: SPN: 4795 FMI: 31 Aftertreatment Diesel Particulate Filter Missing- Condition Exists
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 and the exhaust flow rate was above a calibratiable value.
Action Taken When the Fault Code is Active
1)The ECM will illuminate the amber CHECK ENGINE lamp immediately after the diagnostic runs and fails on two consecutive trips.
2)Active and stationary regeneration of the diesel particulate filter will be disabled.
3)Exhaust Gas Recirculation (EGR) valve operation will be disabled.
4)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
1)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.
2)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.
3)The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4)The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
5)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.
Possible causes:
1) The aftertreatment diesel particulate filter has been removed from the vehicle
2) The aftertreatment diesel particulate filter is cracked or broken
3) The aftertreatment diesel particulate filter differential tubes are installed incorrectly, broken, loose, or have been tampered with
4) 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.
