2015 GMC Sierra 2500 - P2002 Particulate Trap Efficiency Below Threshold

Question

My LML is stuck in a loop. It tries to regen every 100 miles. I'm getting P2002. I checked the soot loads and they go from 30g to 5g after a highway run but the code comes back almost immediately.

I don't have any black smoke, which usually means the DPF isn't cracked. I'm wondering if the differential pressure sensor is lying to the ECM. I've already tried a forced regen with a scan tool and it completed successfully.

OTR_Carlos · Accepted Answer

✅ Confirmed fix: Found the rubber hoses going to the DPF Differential Pressure Sensor were dry-rotted and had a tiny split in the high-side line. This caused an incorrect pressure reading back to the ECM, triggering the P2002. Replaced the hoses with high-temp silicone lines.

BoostedBryan · Answer

Pull the DPF and look at the outlet side. If you see any gray dust or streaks, it's bypassed and needs replacement. If it's clean, check your 9th injector (hydrocarbon injector). If it's leaking or carboned up, it won't get the DPF hot enough to actually oxidize the soot properly.

2015 GMC Sierra 2500 - P2002 Particulate Trap Efficiency Below Threshold

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