CM870 and ISX Engines – FAULT CODE 2346

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Overview

High Exhaust Gas Temperature (Calculated) SMALL | MEDIUM | LARGE

Circuit Description

The exhaust gas temperature is calculated by the electronic control module (ECM). Exhaust gas temperature is derived by the electronic control module, based on engine operating conditions such as intake manifold air temperature, engine speed, injection timing, intake manifold pressure, and fuel flow.

Component Location

There is not a physical exhaust gas temperature sensor in the system. The exhaust gas temperature is a calculation of exhaust gas temperature before the turbocharger and is also known as turbine inlet temperature.

NOTE: Some OEMs have pyrometer gauges mounted in their chassis. Pyrometers measure turbine outlet temperature or (the temperature of the exhaust gas leaving the turbocharger) and will not equal the value monitored with the exhaust gas temperature parameter in INSITE™ electronic service tool.

Shop Talk

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.

Refer to Troubleshooting Fault Code t05-2346