Cummins ISB CM850 (2003-06) Fault Code: 2346 (ISC) PID: SPN: 2789 FMI: 15 Turbocharger Turbine Inlet Temperature (Calculated) – Data Valid but Above Normal Operational Range – Least Severe Level. Turbocharger turbine inlet temperature has exceeded the engine protection limit.

The most common cause of this fault code is low boost. Low boost can be caused by several factors: leaking charge air cooler, failed charge air cooler piping or hose, loose charge air cooler clamps, failed intake manifold pressure sensor, failed variable geometry turbocharger, or failed turbocharger control valve.

NOTE: This code will most likely not be active with no load in the shop. The engine must be loaded to trip this fault code and to determine if the failure has been found and fixed.

Possible repairs:

1)Replace the turbocharger.
2)Repair the air supply from the OEM air tanks.
3)Replace the turbocharger control valve.
4)Replace the turbocharger actuator.