1) A EGR valve assembly internal malfunction that is causing the EGR valve not to close fully.
Another possible cause of this fault code is high resistance in the EGR valve connectors or the EGR valve position +5 volt SUPPLY. A short circuit between the EGR valve position SIGNAL and other pins could also trigger Fault Code 2348.
1)Replace the EGR valve assembly.
Cummins ISX CM870 (2003-06) Fault Code: 2347 PID: S309 SPN: 2790 FMI: 0/15 Turbocharger Compressor Outlet Temperature (Calculated) – Data Valid But Above Normal Operating Range – Least Severe Level. High turbocharger compressor outlet air temperature has been calculated by the engine control module (ECM).
Cummins ISX CM870 (2003-06) Fault Code: 2346 PID: SPN: 2789 FMI: 0/15 Turbocharger Turbine Intake Temperature – Data Valid But Above Normal Operating Range – Least Severe Level. Turbocharger turbine intake temperature has exceeded the engine protection limit.
Cummins ISX CM870 (2003-06) Fault Code: 2321 PID: P190 SPN: 190 FMI: 2/2 Engine speed/position sensor number 1 – engine speed/position glitch detect (crankshaft sensor).
Cummins ISX CM870 (2003-06) Fault Code: 2314 PID: S84 SPN: 1245 FMI: 11/31 Timing Actuator Number 2 CSircuit Error. Error detected on the rear timing actuator circuit.
Cummins ISX CM870 (2003-06) Fault Code: 2313 PID: S83 SPN: 1244 FMI: 11/31 Fueling Actuator Number 2 Circuit Error. Error detected on the rear fueling actuator circuit.
Cummins ISX CM870 (2003-06) Fault Code: 2312 PID: S20 SPN: 635 FMI: 11/31 Timing Actuator Number 1 Circuit Error. Error detected on the front timing actuator circuit.