Get Your GM Truck or SUV Running Right Again
Is your 2004 Envoy, Sierra, Silverado, or other GM vehicle suffering from frustrating issues like a persistent check engine light, poor shifting, or a no-start condition? A failing Powertrain Control Module (PCM) is often the culprit, acting as the brain of your vehicle’s engine and transmission. This replacement engine computer, service number 12586242, is the definitive solution to restore your vehicle’s performance and reliability. We take the guesswork out of the repair by pre-programming the unit to your vehicle’s specific VIN, ensuring it’s ready for a straightforward installation right out of the box.
Common Symptoms & Your Solution
If you’re experiencing any of the following, a faulty PCM is the likely cause. This unit is designed to resolve these problems:
- Check Engine Light with communication-related codes (e.g., P0601, P0606)
- Vehicle won’t start or starts intermittently
- Rough idling or stalling
- Harsh or erratic automatic transmission shifting
- Noticeable decrease in fuel economy
- Failure to pass emissions testing
By installing our programmed 12586242 PCM, you’re not just replacing a part; you’re restoring the core logic that makes your vehicle run efficiently and reliably.
Features & Tangible Benefits
- ✔ VIN-Specific Programming: We flash the module with the latest GM software updates using your vehicle’s VIN. This eliminates the need for expensive dealership programming and ensures perfect compatibility.
- ✔ Plug-and-Play Installation: Because the unit arrives pre-programmed, installation is as simple as disconnecting the old module and plugging this one in. No special tools are required.
- ✔ Restored Engine Performance: Get back the smooth acceleration, proper fuel mixture, and crisp throttle response you’ve been missing.
- ✔ Corrects Transmission Behavior: This module will restore proper communication with your transmission, leading to smooth and predictable shifting.
- ✔ Broad Compatibility: This PCM is a direct replacement for multiple service numbers, including 12586242, 19299226, 89017738, and many more. Please check the fitment list to confirm for your vehicle.
- ✔ Peace of Mind: This unit is backed by our one-year replacement warranty.
A Note From Our Experts
Before replacing your PCM, always perform a full diagnostic. We’ve seen cases where symptoms of a bad PCM were actually caused by a weak battery, poor ground connections, or a faulty alternator. On these 2004 GM trucks, the main ground strap from the engine block to the frame is a common failure point. Taking a few minutes to check these basics can save you time and ensure you’re fixing the right problem. A healthy electrical system is crucial for the longevity of your new computer.
Don’t let a faulty computer keep your reliable GM truck or SUV off the road. This programmed 12586242 PCM is the most effective and straightforward way to solve complex electronic issues and get back to driving with confidence. Simply provide your VIN after purchase, and we’ll handle the rest.
Frequently Asked Questions
How do I provide my VIN number?
After you complete your purchase, you will need to send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot ship your part until we receive this information, as the programming is specific to your vehicle.
Will I need to do any additional programming after installation?
No, the core engine and transmission programming is complete. However, on most GM vehicles, you may need to perform a simple security relearn procedure, which can be done without special tools and typically takes 10-15 minutes. Instructions are readily available online for your specific model. In some cases, a Crankshaft Variation (CASE) relearn may be needed to clear a P1336 code, which requires a scan tool.
How can I be sure this PCM will fit my vehicle?
The best way is to match the service number on your current computer to one of the numbers listed (12586242, YFKX, etc.). You can also use the detailed fitment list on this page to confirm your make, model, and engine size. When in doubt, send us a message with your VIN, and we can verify compatibility for you.
Where is the PCM located on my 2004 GM vehicle?
The location varies slightly. On models like the Trailblazer, Envoy, and Rainier, it’s typically located in the engine bay, next to the air filter box. On full-size trucks and SUVs like the Silverado, Sierra, and Tahoe, it is usually found under the battery on the driver’s side front fender.
What is the warranty on this part?
This unit is backed by our one-year replacement warranty. This covers any defects in the module itself for a full year from the date of purchase.