P2002 — Diesel Particulate Filter Efficiency Below Threshold (Bank 1) — 6.7 Cummins (SCR / DEF)
Diagnostic reference for 6.7 Cummins SCR/DEF 2013–present.
What it means
P2002 is a generic OBD-II DPF efficiency code that applies to this platform; presentation is consistent with generic DPF monitoring.1
Most likely causes
- DPF soot loading / ash accumulation reducing filtration efficiency — DPF efficiency judged by pressure/temperature data is below threshold.1
- Exhaust restriction or abnormal backpressure affecting DPF monitoring — Generic definition: DPF filtering efficiency, judged by pressure/temperature data, is below threshold.1
- Aftertreatment sensor / monitoring data anomaly influencing efficiency calculation1
How to diagnose
- Verify code presence and freeze-frame conditions; confirm P2002 is active on 6.7 Cummins SCR/DEF.
- Review recent regeneration history and driving cycle suitability for passive/active regen.
- Inspect aftertreatment pressure/temperature sensor readings for plausibility vs. expected DPF behavior.
- Check for accompanying aftertreatment codes that may indicate root cause rather than DPF itself.
- Assess DPF differential pressure trend under steady load to evaluate restriction vs. efficiency monitoring logic.
Common mistake to avoid
Cleaning or replacing the DPF before checking its pressure sensor and tubes. Cracked, melted, plugged or wet sensor tubes, or a failing sensor, can set DPF codes while the filter itself is fine. They are cheap to check; clear and verify them before touching the filter. Source: FleetRabbit — P2002 DPF efficiency code causes and fixes.
Parts and tools you may need
- OBD-II scan tool with Cummins enhanced data
- Exhaust backpressure / differential pressure gauge
- Thermal imaging or exhaust temperature probe
Tools you’ll need
- OBD-II scan tool — Reads P2002 and freeze-frame data to confirm active status and view regeneration history on the 6.7 Cummins SCR/DEF.
- DPF differential pressure gauge — Measures pressure drop across the DPF under steady load to distinguish true restriction from efficiency monitoring logic.
- Digital multimeter — Checks plausibility of aftertreatment pressure and temperature sensor voltages and wiring integrity.
- Exhaust backpressure gauge — Quantifies abnormal backpressure that can skew DPF efficiency calculations on this platform.
Rough cost and difficulty
| Likely repair | Parts | Shop labor | Who usually does it |
|---|---|---|---|
| Scan-tool forced (parked) regeneration | — | 0.5–1.5 hrs | DIY with tools and a manual |
| Exhaust backpressure sensor | $60–$200 | 0.5–1.5 hrs | Easy DIY |
| DPF differential pressure sensor | $80–$300 | 0.5–1.5 hrs | Easy DIY |
| DPF professional cleaning (bake and blow) | $300–$700 | 1–3 hrs | Shop |
Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.
When to see a pro
If limp mode, derate, or repeated P2002 with accompanying SCR/NOx codes, have a qualified diesel technician evaluate aftertreatment system. Do not attempt high-pressure fuel or exhaust system repairs without proper training and safety controls.
Check for recalls
Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.
Sources
Repair videos: P2002 on the 6.7 Cummins '13+
Third-party videos, not ours — picked for this engine. Confirm anything against the factory service information for your truck.
Spotted an error, or something missing? Tell us
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