Is Your Truck Running Rough? Get Back on the Road with Confidence.
If your 2004 Chevrolet Avalanche 1500—or another compatible GM truck or SUV—is suffering from a persistent check engine light, erratic performance, or a no-start condition, a failing Engine Control Module (ECM) is often the culprit. This isn’t just an inconvenience; it’s a critical failure that compromises your vehicle’s reliability and performance. This replacement ECM, part number 12586242, is the definitive, hassle-free solution to restore your vehicle’s brain and get it running like it should.
We take the guesswork and expensive dealership trips out of the equation. Before this unit ships, we program it specifically to your vehicle’s unique VIN using the latest official GM software updates. This ensures complete compatibility and a straightforward installation process, so you can get your trusted truck or SUV back in service quickly. This is the most reliable way to solve complex electronic issues and restore the dependable performance you rely on every day.
Common Symptoms & Your Solution
A failing ECM can cause a wide range of frustrating issues. If you’re experiencing any of the following, this pre-programmed module is your solution:
- Persistent Check Engine Light (CEL)
- Diagnostic Trouble Codes (DTCs) like P0601, P0602, or P0606
- Engine stalling, stumbling, or rough idling
- Poor fuel economy
- Difficulty starting or a complete no-start condition
- Transmission shifting problems
- Loss of communication with the diagnostic scan tool
By replacing your old module with this correctly programmed 2004 Avalanche 1500 ECM 12586242, you are directly addressing the root cause of these problems.
Features & Benefits
- ✔ Plug & Drive Ready: Arrives programmed to your VIN. No need for expensive dealership flashing or additional tools.
- ✔ Restored Engine Performance: Re-establishes factory fuel trim, ignition timing, and transmission shift points for a smooth, powerful ride.
- ✔ Latest GM Software: Flashed with the most current GM updates to fix original bugs and improve overall performance and stability.
- ✔ Guaranteed Compatibility: A direct replacement for service numbers 12586242, 19299226, 89017738, YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, and YHTN.
- ✔ Clear Fault Codes: The definitive fix for stubborn internal module fault codes that won’t go away.
- ✔ Peace of Mind: This unit is backed by our one-year replacement warranty.
An Expert’s Note on DTC P0601: As a technician, one of the most definitive codes I see for computer failure is P0601: ‘Internal Control Module Memory Check Sum Error.’ This isn’t a sensor or wiring issue; it means the ECM’s internal self-check has failed. It’s like a computer’s hard drive becoming corrupted. There’s no fixing it—the only proper repair is a replacement. Installing a properly programmed 2004 Avalanche 1500 ECM 12586242 is the direct and permanent solution to this specific, critical fault.
Frequently Asked Questions
What do I need to do after installing this ECM?
In most cases, you will only need to perform a security relearn procedure, also known as a CASE relearn. This is a simple process that can often be done without special tools and involves a sequence of key turns. Instructions are readily available online for your specific model, or your mechanic can perform it in minutes.
How do I provide my vehicle’s VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). We will then program the module before shipping it to you. Please double-check your VIN for accuracy to ensure perfect compatibility.
Is this the correct part for my vehicle?
This module fits a wide range of 2004 GM trucks and SUVs. The best way to confirm is to match the service number on your original computer to 12586242 or one of the other compatible numbers listed in the description. If you are unsure, please contact us with your VIN before ordering.
What if my original part has a different service number?
This ECM replaces multiple service numbers, including 19299226, 89017738, and several others listed above. As long as your original number is on our compatibility list, this unit will function as a direct replacement.
What does ‘VIN-programmed’ actually mean?
It means we load your vehicle’s specific software, including engine and transmission calibrations and security information, directly onto the module using your VIN. This makes the unit a true plug-and-drive part, saving you a trip to the dealership for expensive programming services.