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.

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

NOTE: Prior to running INSITE? electronic service tool EGR valve and EGR valve/turbocharger operational test, the ECM Calibration software phase could possibly need to be updated to the latest software phase. The ECM calibration phase software can be checked in INSITE? electronic service tool, under ‘Features and Parameters’. Expand the selection for ‘System ID and Dataplate’ and go to ‘Calibration Information’. If the software phase is earlier than shown below, recalibrate the ECM using the January 2006 INCAL? CD-ROM, or later. Engines with the software phase listed below or later do not require a recalibration.

ISX engines with CM870 (engines built after January 2004) require software phase 06050402.

ISX engines with CM870 (engines built before January 2004) require software phase 05050000.

This is a warrantable calibration change.

This fault code can also be caused be a Turbocharger Fuel Control (TFC) derate which can be viewed in INSITE? electronic service tool, under the User Fueling State. TFC derates can be caused by several factors: high exhaust temperatures, high turbocharger compressor inlet temperatures, and high turbocharger compressor outlet temperatures.

NOTE: The engine must be loaded to trip this fault code and to determine if the problem has been found and fixed. It is possible to cause the fault code to log when the engine is placed on a dynamometer. The fault code will trip because of the stationary nature and high temperatures encountered on the dynamometer.

Possible repair:
1)Use the INCAL? Calibration DVD-ROM with the proper calibration software phase to calibrate the ECM.
2)The engine power output was derated to limit the exhaust temperatures. This is normal operation. No repairs are necessary.
3)Repair air leaks.
4)Replace the turbocharger assembly.
5)Replace the turbocharger control valve.
6)Repair the air supply from the OEM air tanks.
7)Replace the turbocharger control shutoff valve filter.
8)Replace the turbocharger control shutoff valve.
9)Replace the variable geometry turbocharger.