Cummins ISB CM850 (2003-06) Fault Code: 2346 (ISB) PID: SPN: 2789 FMI: 15 Exhaust gas temperature – data above normal. High exhaust temperature has been calculated by the electronic control system.

The most common cause of this fault code is low boost. Low boost can be caused by several factors:

1)Leaking charge air cooler
2)Damaged charge air piping or hose
3)Loose charge air cooler clamps
4)Failed intake manifold pressure sensor
5)Failed variable geometry turbocharger.

NOTE: This fault code will most likely not become active under conditions of the engine being unloaded and in the shop. The engine must be loaded to trip this fault code and to verify if the failure has been fixed.

Possible repairs:

1)Replace the turbocharger.