Cummins ISX11.9 CM2250 (2010-12) Fault Code: 334 PID: 116 SPN: 110 FMI: 2 Engine Coolant Temperature- Data Erratic, Intermittent, or Incorrect

Circuit Description
The engine coolant temperature sensor is used by the engine control module (ECM) to monitor the engine coolant temperature. The ECM monitors the voltage on the signal pin and converts this to a temperature value. The engine coolant temperature value is use by the ECM for the engine protection system and engine emission control.

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

Conditions for Running the Diagnostics
The engine must be turned off for period of 10 hours before this diagnostic will run. This diagnostic runs when the keyswitch is turned to the ON position after an 10 hour cold soak.

Conditions for Setting the Fault Codes
If coolant temperature is found to be higher than other engine temperature sensors by a calibratable value, the fault code is logged.

Action Taken When the Fault Code is Active
The ECM illminates the amber CHECK ENGINE lamp and/or malfunction indicator lamp (MIL) on the second consecutive trip that the diagnostic runs and fails.
The ECM will estimate engine coolant temperature.
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-type driving and steady-state highway-type 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, utilize a routine that incorporates acceleration and motoring events, steady-state highway-type operation, and load. This will simulate normal driving and allow the diagnostics in the ECM to run.
Monitor engine coolant temperature using INSITE? electronic service tool during the Diagnostic Road Test or Dynamometer run. Coolant temperature should remain in the normal operating range.
The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.
For On-Board Diagnostic (OBD) engines, the ECM will turn off the MIL after three consecutive trips where the diagnostic runs and passes.
The Reset All Faults command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk
Possible causes of this fault code include:

In-range malfunction of the engine coolant temperature sensor
High resistance in the engine coolant temperature sensor SIGNAL or RETURN lines.

Possible Cause:
1) Thermostat failure
2) ECM failure