DEF Dose Control
This bulletin applies to 2013-2014 3500 series Ram Cab Chassis vehicles equipped with a 6.7L Cummins turbo diesel engine, for the purpose of selectively erasing and reprogramming the Doser Control Unit (DCU) with new software.
Software improvement are available for the diesel exhaust fluid (DEF) system. This will prevent or reduce unnecessary MIL illumination for P208D (diesel exhaust fluid reductant pump control circuit high) or P202E (diesel exhaust fluid reductant injector performance).
Using a scan tool (wiTECH) with the appropriate diagnostic procedures available in TechCONNECT, verify that all engine systems are functioning as designed. If DTCs are present, record and repair as needed before proceeding with this bulletin.
Install a battery charger to ensure that battery voltage does not drop below 13.2 volts. Do not allow charging voltage to climb above 13.5 volts during the flash process.
1. Flash reprogram the DCU (follow the wiTECH diagnostic application for flashing). Flash PCM service bulletin 18-018-13 Rev. B or later should be used for pick up trucks. Flash PCM service bulletin 18-025-13 Rev. A or later should be performed for cab chassis trucks.
2. After DCU reprogramming, clear any DTCs that may have set in other modules.