Cummins ISB4.5 CM2150 Fault Code: 2347 PID: SPN: 2347 FMI: 0 Turbocharger Compressor Outlet Temperature (Calculated) – Data Valid but Above Normal Operating Range – Least Severe Level.

Circuit Description
The turbocharger compressor outlet air temperature is calculated by the ECM. Turbocharger compressor outlet air temperature is derived by the ECM, based on engine operating conditions such as turbocharger compressor inlet air temperature, barometric pressure, turbocharger speed, engine speed, intake manifold air temperature, and intake manifold pressure.

Component Location
There is not a physical turbocharger compressor outlet temperature sensor in the system. The turbocharger compressor outlet air temperature is a calculation of temperature of the air after it is compressed by the turbocharger compressor, but before exhaust gas recirculation (EGR) is mixed into the system and before it enters the charge air cooler.

Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes
The ECM detects that the calculated turbocharger compressor outlet temperature is greater than 238°C [460°F].

Action Taken When the Fault Code is Active
-The ECM logs the fault code immediately when the temperature threshold is exceeded.
-Fuel is limited in an attempt to decrease the calculated compressor outlet temperature.

Conditions for Clearing the Fault Code
The ECM will turn off the amber CHECK ENGINE light immediately after the diagnostic runs and passes.

Possible Causes
-Air intake leaks allowing hot under-hood air to enter the intake system
-Faulty intake manifold pressure readings
-High turbocharger speed readings
-Malfunction of barometric pressure sensor
-Stuck variable geometry turbocharger.

Note: Unless the fault is caused by a malfunction in the barometric pressure sensor or intake manifold pressure sensor, this fault code will most likely not be active with no load in the shop. The engine will most likely need to be loaded to trip this fault code, and to determine if the malfunction has been found and fixed.