CM871 and CM876 Electronic Control Systems, ISX and ISM Engines – FAULT CODE 2346

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Overview

ISX and ISM – Electronic Control Module SMALL | MEDIUM | LARGE

Circuit Description

The exhaust gas temperature is calculated by the electronic control module (ECM). The exhaust gas temperature is derived by the ECM, 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 know as turbine inlet temperature.

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

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 turbine inlet temperature is greater than a calibratible value.

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 exhaust gas temperature entering the turbocharger.

Conditions for Clearing the Fault Code

The fault code will be set inactive immediately after the diagnostic runs and passes.

Shop Talk

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe™ Online for applicable fixes to the calibration stored in the ECM. If necessary, calibrate the ECM. Refer to Procedure 019-032 in Section 19.

This fault code is an information fault code indicating that the engine has been derated for high turbine inlet temperature (exhaust temperature). No troubleshooting is necessary for this fault code. It is only an indicator that the engine power was derated to limit the exhaust temperature.

If the condition continues to exist, Fault Code 2451 will most likely become active.

If the condition continues to exist and Fault Code 2451 does not become active or does not show any inactive counts, a possible cause is a stuck in range turbocharger compressor inlet temperature sensor.

Refer to Troubleshooting Fault Code t05-2346.