Restore Peak Performance to Your GM Truck or SUV
Is your 2004 GMC Sierra 2500, Silverado, Tahoe, or other GM vehicle suffering from perplexing electrical issues, a persistent check engine light, or poor engine performance? The Powertrain Control Module (PCM), the brain of your vehicle’s engine and transmission, is often the culprit. A failing PCM can lead to a cascade of problems that are frustrating to diagnose and can leave your vehicle unreliable. This replacement PCM, service number 12586242, is the definitive solution to restore your vehicle’s factory performance, drivability, and fuel economy.
This isn’t just a generic, off-the-shelf part. We provide a fully programmed and updated module specific to your vehicle. Upon purchase, simply provide us with your vehicle’s VIN. Our technicians will then flash the unit with the latest official GM software calibration for your exact make and model. This critical step ensures seamless communication between the PCM and all other vehicle systems, eliminating compatibility issues and ensuring a straightforward installation process.
From the Diagnostic Bay
We had a 2004 Silverado 2500 come in with a complaint of intermittent stalling and a check engine light that would come and go. The owner had already replaced the fuel pump and several sensors with no luck. Our initial scan showed a handful of seemingly unrelated communication error codes. Instead of chasing ghosts, we hooked up our scope to the PCM’s power and ground circuits. We found an inconsistent voltage drop when the engine was under load, pointing to an internal failure within the original computer. After installing one of our VIN-programmed 12586242 modules and performing the security relearn, the truck ran perfectly. No more stalling, no more codes. It’s a classic case where the central computer was causing system-wide confusion.
Diagnosing a Faulty 2004 Sierra 2500 PCM
A failing engine computer can manifest in numerous ways, often mimicking other component failures. If you’re experiencing any of the following, your PCM may be at the end of its service life. This module is the correct replacement to solve these common issues.
Common Symptoms of PCM Failure
- ✔ Persistent Check Engine Light (CEL) with various communication or sensor codes.
- ✔ Vehicle fails to start or experiences intermittent no-start conditions.
- ✔ Poor fuel economy and noticeable loss of engine power.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Engine stalling, sputtering, or misfiring for no apparent reason.
- ✔ Failure to pass state emissions testing.
- ✔ Inconsistent operation of electronic components like gauges or fans.
A Simple, Reliable Solution
Don’t let a faulty PCM keep your truck off the road. Our process is designed to be as simple as possible. You order the part, provide your VIN, and we handle the complex programming. The module arrives at your door ready for installation. In most cases, after installation, you will only need to perform a simple security relearn procedure (often called a CASE relearn), which can be done without special tools. This ensures your vehicle’s anti-theft system recognizes the new computer. This module is a direct replacement for service numbers 12586242, 19299226, 89017738, YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, and YHTN, making it a versatile solution for a wide range of GM trucks and SUVs from the 2004 model year.
Frequently Asked Questions
Do I need to have this PCM programmed?
No, the programming is included in your purchase. We flash the module with your vehicle’s specific VIN and the latest GM software before it ships, making it ready for installation.
What is a security relearn procedure?
The security relearn, or CASE relearn, is a simple procedure that syncs the new PCM with your vehicle’s anti-theft system. It typically involves a sequence of turning the ignition key on and off. Instructions are readily available online for your specific model, and no special scan tools are required.
Where is the PCM located on my 2004 GM truck?
On most 2004 GM full-size trucks and SUVs like the Sierra, Silverado, and Tahoe, the PCM is located in the engine bay on the driver’s side, under the battery tray or near the airbox. On models like the Envoy and Trailblazer, it is typically next to the airbox.
Is this a guaranteed fix for my vehicle’s problems?
While this PCM will correct issues caused by a faulty module, it’s essential to ensure your vehicle has been properly diagnosed. This part will not fix problems related to other faulty components like sensors, wiring, or mechanical failures.
How do I confirm this is the right part for my vehicle?
The best way is to match the service number on your original computer to one of the numbers listed in this description (e.g., 12586242, YFKD). If you are unsure, please contact us with your VIN, and we will verify compatibility for you.