Hello just hoping someone can help me out here. My APU was just serviced, and now EVERY DAY it wants to Regen (its the old tripac with the regen switch on the dash). So I regen going down the road, stop for the night click it on and within an hour the yellow light is back on wanting to regen. Then about 5 hours or so later, it shuts off and starts flashing the red DPF Fault with code 43. I looked it up and it says that it is "Unit Forced to Low Speed Modulation" So I clear the code in the morning, do a regen and start the entire process over again.

And I go through this process daily. Anyone have any suggestions on how to fix the problem?






Source:http://www.tknw.com/alarmcodes.htm