Cummins ISX12 CM2250 (2010-12) Fault Code: 2659 PID: 110 SPN: 110 FMI: 31 Engine Coolant Temperature- Condition Exists

Circuit Description
When the engine coolant temperature nears the engine protection limits, the EGR valve will be closed to reduce the coolant temperature. This fault code is used as an information fault code, only indicating that the EGR valve has closed.

Component Location
The engine coolant temperature sensor is located on the thermostat housing.

Conditions for Running the Diagnostics
This diagnostic runs continuously when engine speed is greater than 500 rpm.

Conditions for Setting the Fault Codes
The fault code is set active when the EGR valve is closed to reduce engine coolant temperature.

Action Taken When the Fault Code is Active
The engine control module (ECM) illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
Conditions for Clearing the Fault Code
To validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop-and-go city driving and steady state highway driving. It may be necessary to load the unit for certain diagnostics in the ECM to run.
To validate the repair using a Chassis Dynamometer Test, utilize a routine that incorporates acceleration and motoring events, steady state highway operation, and load. This will simulate normal driving and allow the diagnostics in the ECM to run.
The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults.

Shop Talk
When the engine coolant temperature nears the engine protection limits, the EGR valve will be closed to reduce the coolant temperature. This fault code is used as an information fault code, only indicating that the EGR valve has closed. No malfunction has occurred to cause this fault code. Other engine protection fault codes will be active if the engine coolant temperature has exceeded the engine protection limits.

Possible Cause:
1) ECM calibration