Description
Part Description
This Engine Control Module (ECM) was removed from a 2004 GM Trucks Silverado 1500 equipped with a 4.8L engine. The electronic brain box is located under the battery on the left front side of the engine compartment. This unit has been inspected by our technicians and is currently on the shelf ready to ship.
The Engine Control Module is the computer that controls your engine’s fuel injection, ignition timing, emissions systems, and other critical functions. ECMs commonly fail due to electrical surges, water damage, or internal component wear over time. When your ECM fails, your vehicle may not start, run poorly, or trigger multiple check engine lights.
603 Auto Salvage maintains over 50,000 used auto parts in stock from more than 1,100 vehicles. Our experienced team can help you find the right ECM for your Silverado and provide programming guidance. Browse our online inventory or call us to verify compatibility and availability. 50,000+ parts in stock from over 1,100 vehicles. Contact us or call (603) 392-7313 for anything you need.
Part Specifications
| Part | Engine Control Module (ECM) – Electronic Brain Box |
| Interchange # | 7143 |
| OEM Part Number | 12586242, 12583660 |
| Side | N/A |
| Part Grade | X — Grade X – Inspected and ready to ship, pulled from 4.8L engine |
| Warranty | 90-Day Warranty (Standard warranty for electronic control modules) |
| Type | Used OEM |
Vehicle Information (Donor)
| Year / Make / Model | 2004 GM TRUCKS SILV15 |
| VIN | N/A |
| Vehicle Stock # | PCM5117 |
Our Testing & Inspection Process
Every part at 603 Auto Salvage is inspected before listing. Here is what was verified on this Engine Control Module (ECM) – Electronic Brain Box:
| ✅ Connector Pins | All pins intact and free of corrosion |
| ✅ Housing Integrity | No cracks or damage to ECM case |
| ✅ Mounting Tabs | Secure mounting points verified |
| ✅ Internal Components | No signs of water damage or burning |
Compatibility — What Vehicles Does This Part Fit?
Based on interchange #7143, this part fits the following vehicles. Always confirm fitment with your mechanic before purchasing.
| Year(s) | Make | Model | Notes |
|---|---|---|---|
| 2004 | GM Trucks | Silverado 1500 | 4.8L engine with automatic transmission – Contact us for full compatibility list |
Questions? Need a shipping quote? Call us now:
603 Auto Salvage | 233 Main St, Plaistow, NH 03865
Mon–Fri 8am–4:30pm | Sat 8am–2pm | Sun Closed
Warranty & Shipping
Frequently Asked Questions
Will this ECM need to be programmed for my 2004 Silverado?
Yes, this ECM will need to be programmed to your vehicle’s VIN and security system by a qualified technician or dealership. Programming ensures proper communication with your vehicle’s other modules.
How do I know if my Engine Control Module is failing?
Common symptoms include no-start conditions, rough idle, poor fuel economy, multiple check engine lights, or the engine cutting out while driving. A diagnostic scan can confirm ECM-related fault codes.
What’s the difference between ECM, PCM, and ECU?
ECM (Engine Control Module) controls only engine functions, while PCM (Powertrain Control Module) controls both engine and transmission. ECU is a general term for Electronic Control Unit covering various vehicle computers.
Can I install this ECM myself?
While physically installing the ECM is straightforward, programming requires specialized equipment. Most customers have the part installed and programmed at a shop or dealership to ensure proper operation.
What causes Engine Control Modules to fail?
ECMs commonly fail due to electrical surges from jump-starting, water damage from flooding, overheating, or simply age-related component wear. Power supply issues and corroded connections can also damage the module.
Related Parts & Resources
OEM Part Numbers & Cross-Reference
Looking for this part by number? Here are the reference numbers:
| GM Part Number | 12586242 |
| Alternate GM Number | 12583660 |
| Interchange Group | 7143 |
Price Comparison — Why Used OEM Makes Sense
| Source | Price Range | Warranty | Notes |
|---|---|---|---|
| Dealer (New OEM) | $400-600 | 1 year | Brand new, longest wait time |
| Aftermarket | $250-400 | Varies | Non-OEM fitment, quality varies |
| Other Salvage Yards | $150-250 | 30–60 days | Varies in quality and testing |
| 603 Auto Salvage | $100 | 90-Day Warranty | Tested, Grade X, ships in 24hrs |
Installation Notes
- Disconnect battery before removing or installing ECM to prevent electrical damage
- Take photos of connector positions before disconnection for easier reassembly
- Keep the ECM in anti-static packaging until installation to prevent damage
- Have the ECM programmed immediately after installation for proper vehicle operation
🔍 Free Fitment Check
Call us with your VIN and we will verify compatibility for free. No obligation, no pressure — just answers.
Our parts specialists check interchange data in real-time
Estimated Shipping Costs by Region
This part ships via FedEx Ground. Prices are estimates — call for an exact quote to your zip code.
| Region | Estimated Cost | Transit Time |
|---|---|---|
| New England (NH, MA, ME, VT, CT, RI) | $15 – $30 | 1–3 business days |
| Northeast (NY, NJ, PA, MD, VA) | $20 – $40 | 2–4 business days |
| Southeast (FL, GA, NC, SC, TN) | $25 – $45 | 3–5 business days |
| Midwest (OH, MI, IL, IN, WI, MN) | $30 – $50 | 3–5 business days |
| Southwest (TX, AZ, NM, OK) | $35 – $55 | 4–6 business days |
| West Coast (CA, OR, WA) | $40 – $65 | 5–7 business days |
Local pickup is always free. Free delivery within 30 miles of Plaistow, NH.
Why Buy From 603 Auto Salvage?
- 50,000+ parts in stock from over 1,100 vehicles on-site in Plaistow, NH
- Every part inspected before listing — no guesswork
- Family-owned salvage yard — real people, not a call center
- 90-Day Warranty on this part
- Fast shipping — most orders ship within 24 hours
- Competitive pricing — save 50–70% vs dealer prices
- Serving New Hampshire, Massachusetts & all 50 states
Ready to order? Call (603) 392-7313 or add to cart above. We are here to help.




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