Cummins X12 CM2350 X119B (2018 & Newer) Fault Code: 3342 PID: PID 091 SPN: 4752 FMI: 18 Engine Exhaust Gas Recirculation Cooler Efficiency- Data Valid But Below Normal Operating range- Moderately Severe Level

Circuit Description
The exhaust gas recirculation (EGR) temperature sensor is a variable resistor sensor and is used to measure the temperature of the EGR gas flow after it exits the EGR cooler. The engine control module (ECM) supplies 5 volts to the EGR temperature signal circuit. The ECM monitors the change in voltage caused by changes in the resistance of the sensor to determine the EGR flow temperature.

The EGR temperature value is used by the ECM for the engine protection system and engine emissions control.

Component Location
The EGR temperature sensor is located on the EGR connection tube between the EGR cooler and the air intake connection.

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

Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the EGR temperature was greater than a threshold for 5 seconds.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL) after the diagnostic fails on two consecutive trips.

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.
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 immediately after the diagnostic runs and passes.
For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (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:

A malfunctioning EGR temperature sensor
A malfunctioning EGR cooler.

Possible Cause:
1) Coolant Level
2) ECM failure