04.5-05 Silverado Sierra 2500HD 6.6L LLY Underhood Engine ECM Wiring Harness 925
04.5-05 Silverado Sierra 2500HD 6.6L LLY Underhood Engine ECM Wiring Harness 925
Item Details
VIN must be 17 characters and cannot contain I, O, or Q.
Item Description
04.5-05 Silverado Sierra 2500HD 6.6L LLY Underhood Engine ECM Wiring Harness 925
Engine wiring harness from a 2005 GMC Sierra 2500HD LLY. This harness connects to the ECU and goes throughout the engine bay, to the fuse box, and to the transmission as well. This was removed from a running and driving truck. All wires and connectors are intact and undamaged. The conduit and tape throughout the harness is in good condition. This does NOT include the injection harness. The pictures are of the actual item you will receive.
Fits the following models with with 6.6L LLY engine (8th Digit of VIN# "2"), automatic transmission (RPO M74), and electronic shift four-wheel drive (RPO NP1) ONLY:
• 2004.5 Chevrolet Silverado 2500HD
• 2005 Chevrolet Silverado 2500HD
• 2004.5 GMC Sierra 2500HD
• 2005 GMC Sierra 2500HD
This will NOT fit any 2004 models with LB7 engine.
This does NOT include the injection harness.
Importapart is an auto recycler based in Hazelwood, Missouri. Every part we sell is a real, inspected OEM piece pulled from our own inventory — no aftermarket guesswork.
Questions on fitment or availability? Email Importapartsales@gmail.com or reach us through our contact page and we’ll get back to you within one to two business days. Hours are Mon–Fri, 9am–5pm CST.
We accept all major credit and debit cards and the other payment methods shown at checkout, processed securely through Shopify. Payment is due in full at the time of purchase, and sales tax is applied where required.
For programmed ECU/ECM/PCM orders, be sure to submit your VIN, odometer reading, and current part number at checkout so we can program the unit before it ships.
We ship to all 50 states. Most orders leave our Hazelwood, MO shop within 1–2 business days by FedEx, UPS, or USPS, and you’ll get tracking by email as soon as it’s on the way.
Heavy items like engines, transmissions, and body panels may ship freight — we note that on the listing when it applies. Alaska and Hawaii have a flat-rate surcharge calculated at checkout. We don’t ship to PO Boxes or outside the U.S.
Local pickup is available at our Hazelwood facility by appointment — call ahead to set a time.
Returns are accepted within 60 days. A 20% restocking fee applies to standard returns, but it’s waived if we sent the wrong part, it arrived damaged, or it’s verified defective. Inspect your order on arrival and contact us within 7 days in those cases — we cover return shipping.
Programmed ECU/ECM/PCM modules are returnable only if defective, damaged, or incorrect. Because each one is programmed to the VIN you provide, we can’t take them back for compatibility issues from an incorrect VIN, odometer, or part number — double-check before you order.
Approved refunds are issued to your original payment method within 10 business days.
Every part carries a 60-day limited warranty against defects from the date it’s delivered. It covers manufacturing defects, parts that fail to function as described, and internal mechanical or electrical failure under normal use.
Not covered: damage from improper installation, accident, misuse, or modification; normal wear and tear; labor, towing, or rental costs; racing, off-road, or commercial use unless stated; and items with broken warranty seals.
To file a claim, email Importapartsales@gmail.com with your order number, a description of the problem, and photos or video if possible. We’ll respond within one business day.
Compatible Vehicles
| Notes | Make | Model | Year | Trim | Engine |
|---|---|---|---|---|---|
| Chevrolet | silverado 2500 hd | 2005 | base crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2005 | base extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2005 | base standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2005 | ls crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2005 | ls extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2005 | ls standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2005 | lt crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2005 | lt extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2005 | wt crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2005 | wt extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2005 | wt standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | base crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | base extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | base standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | sle crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | sle extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | sle standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | slt crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | slt extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | wt crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | wt extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2005 | wt standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | base crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | base extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | base standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | ls crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | ls extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | ls standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | lt crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | lt extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | wt crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | wt extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Chevrolet | silverado 2500 hd | 2004 | wt standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | base crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | base extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | base standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | sle crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | sle extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | sle standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | slt crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | slt extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | wt crew cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | wt extended cab pickup 4-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged | |
| Gmc | sierra 2500 hd | 2004 | wt standard cab pickup 2-door | 6.6l 6599cc 403cu. in. v8 diesel ohv turbocharged |