Reflash the Ram
This bulletin applies to a range of Dodge Ram 4x4 trucks equipped with an electronic transfer case and built before Jan. 6, 2012, where the “Service 4WD” light is illuminated and the DTCM requires reprogramming.
This involves the following trucks: 2011-2012 1500, 2012 3500, 2012 2500 and 2012 4500/5500 cab chassis.
The technician may find DTC C2201 (FDCM/DTCM internal DTC) is set in the DTCM. When the system detects this, it shuts down the 4WD capability for the remainder of the drive cycle.
This condition is not monitored in 2WD mode. Updating the DTCM software will correct the condition. Use wiTECH software release 12.02 or higher.