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Chevy / GMC HD · Research

Duramax
Issues & Fixes.

GM 6.6L Duramax from the LB7 forward — six engine generations, six distinct sets of issues. Fuel pressure codes, water-pump failures, injector groupings, and the cooling-system quirks that differentiate one Duramax year from another.

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Generation // 01

LB7

P0193

LB7 Duramax — P0193 (Fuel Rail Pressure Low)

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P0308

LB7 Duramax — P0308 (Cylinder 8 Misfire) and Glow Plug Feedback Diagnostics

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LB7 Duramax — White Smoke and Hazing Exhaust (Injector Diagnostics)

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Generation // 02

LLY

LLY Duramax — Chronic Overheating (Cooling System Diagnosis)

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P2149

LLY Duramax — P2149 (Injector Positive Voltage Relay Circuit, Group 2)

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LLY Duramax — Repeated Water Pump Failure (Cooling System Root-Cause Diagnosis)

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Generation // 03

LBZ

P2563

LBZ Duramax — P2563 (Turbocharger VGT Position Sensor Performance)

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Generation // 04

LMM

LMM Duramax — DPF Regen Issues (Failed Regens, Reduced Power)

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Generation // 05

LML

LML Duramax — CP4.2 Pump Failure (Same Story, Different Engine)

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LML Duramax — P0420, P2463, P24A0 (Hydrocarbon Injector / “9th Injector”)

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Generation // 06

L5P

L5P Duramax — Common Emissions System Issues (DEF, NOx, DPF)

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Don’t See Your Issue?

We don’t publish every fault we’ve ever worked on. If your Duramax is doing something weird and you can’t find it here, call us — we’ve probably seen it.

Call (903) 292-0400 Request Estimate