2007-2010 Ram 3500/4500/5500 cab chassis trucks equipped with the 6.7L Cummins diesel engine and a snow plow may cause airflow through the radiator to be disrupted, resulting in higher than normal engine temperatures. The 6.7L Cummins ECM is equipped with software that can fully engage the fan clutch to allow an increase of airflow through the radiator.
Customers can initiate the fan clutch operation by performing the following button sequence:
1. Turn the ignition to the run position, and start the engine.
2. Simultaneously press and release the Cruise Control “Cancel” button/lever and the “Exhaust Brake” button. Repeat this sequence four times within five seconds. The chime will sound twice as an audible indicator that the function is engaged.
3. To disable the function, repeat the same procedure. The chime will sound four times as an audible indicator that the function is disengaged.
Customers should be made aware that an increase in fan noise and a decrease in fuel economy may result when using this feature.
NOTE: 2007 through early 2009 models were not originally equipped with the fan clutch software. However, recently released software does include this enhancement. Ensure that the ECM software is at the latest level. If not, flash the ECM.