2016 Ram 2500 - P2002 Code and 'Service Exhaust System' Message

Question

Hey guys, my Ram is stuck in a 'See Dealer' limp mode with a P2002 code. It started acting up about two weeks ago during a long highway haul. I tried forcing a stationary regen with my scan tool, but it fails about 10 minutes into the cycle every time.

I checked the pressure tubes for cracks or soot buildup but they look fairly clean. The truck has 145k miles on it and I'm worried the DPF is actually cracked or just completely end-of-life. Gas mileage has dropped from 17mpg down to about 11mpg lately.

SuspSpecSal · Accepted Answer

✅ Confirmed fix: Found the issue was actually the DPF differential pressure sensor itself having internal moisture issues, causing false readings. However, upon deeper inspection, the DPF was also 85% soot-loaded. Replaced the sensor with an OEM Mopar unit and performed a bench cleaning on the DPF. Truck has been out of limp mode for 2,000 miles now.

VolvoVince · Answer

You need to pull the DPF off and look at the outlet face. If you see any black soot on the exhaust side of the filter honeycomb, the substrate is cracked and there is no fixing it. A P2002 on a Cummins usually means the sensor is detecting too little pressure differential because the air is bypassing the filter through a crack.

2016 Ram 2500 - P2002 Code and 'Service Exhaust System' Message

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