Restore Peak Performance to Your GM Truck or SUV
Is your 2004 GMC Sierra 2500, Silverado, Tahoe, or other compatible GM vehicle suffering from perplexing engine issues? A faulty Powertrain Control Module (PCM) is often the culprit behind problems like a persistent check engine light, poor engine performance, stalling, or even a no-start condition. This replacement PCM, part number 12586242, is the definitive solution to restore your vehicle’s reliability and drivability. As the central computer for your engine and transmission, a fully functional PCM is critical for managing everything from fuel mixture and ignition timing to transmission shift points and emissions controls.
We take the guesswork out of the repair process. Unlike sourcing a used module from a junkyard that may have unknown issues or incorrect software, this unit is meticulously prepared for your specific vehicle. Upon purchase, simply provide us with your vehicle’s VIN. Our technicians will then program the module with the latest, most up-to-date software directly from General Motors. This ensures optimal performance, fuel efficiency, and remedies many common software-related drivability issues that older calibrations may have had. This is a direct-fit replacement, ready for installation right out of the box.
From the Diagnostic Bay
We had a 2004 Silverado 2500 with the 6.0L V8 come in with a stubborn P0300 random misfire code that just wouldn’t go away. The owner had already spent a small fortune replacing spark plugs, wires, and even an ignition coil pack, but the misfire persisted, especially under load. After confirming fuel pressure and checking for vacuum leaks, we hooked up our diagnostic scope to the ignition control signal at the PCM. We found that the signal for cylinder 3 was erratic and weak. The driver circuit inside the original PCM had failed. We installed one of our VIN-programmed modules, performed the security relearn, and the truck ran perfectly. It’s a classic case where throwing parts at a problem doesn’t work; you have to address the root cause, which was the brain itself.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) illumination
- ✔ Engine stalling, stumbling, or misfiring
- ✔ Intermittent or complete no-start condition
- ✔ Noticeable decrease in fuel economy
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Failure to pass state emissions testing
- ✔ Communication errors with diagnostic scan tools
Guaranteed Fitment for Your 2004 Sierra 2500 PCM
This module is the correct replacement for a wide range of 2004 General Motors trucks and SUVs. It directly replaces OEM part number 12586242 and service numbers including YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, and YHTN. While this is a perfect match for the 2004 Sierra 2500 PCM, it also fits models like the Escalade, Hummer H2, Suburban, Yukon, Rainier, and more. To ensure a perfect match, please verify that your original module carries one of the listed service numbers. Our VIN programming service guarantees that the software will be a perfect match for your vehicle’s specific configuration.
Installation Process
Replacing the PCM is a straightforward mechanical process. On most trucks like the Sierra and Silverado, it is located on the driver’s side, under the battery tray. After disconnecting the battery, you can unbolt the module and disconnect the electrical harnesses. Once the new module is installed and the battery is reconnected, you will likely need to perform a simple security relearn procedure (often called a CASE relearn or Passlock relearn) to allow the vehicle to start. This procedure can typically be done without special tools and instructions are widely available online or in service manuals.
Frequently Asked Questions
Do I need to get this PCM programmed?
No. We handle all the programming for you before shipment. Simply provide your vehicle’s 17-digit VIN during or after checkout, and we will flash the module with the latest GM-certified software for your specific vehicle configuration.
Where do I find my vehicle’s VIN?
Your VIN can be found on a metal plate on the driver’s side of the dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
Is this a difficult part to install?
The physical installation is relatively simple for anyone with basic mechanical skills, typically involving removing the battery and a few bolts. The most important step after installation is performing the security relearn procedure, which syncs the new PCM with your vehicle’s anti-theft system.
What if I install it and my vehicle doesn’t start?
The most common reason for a no-start condition after installation is an incomplete or improperly performed security relearn procedure. Please ensure you follow the correct steps for your specific model. If issues persist, it could indicate another underlying problem with the vehicle that was not related to the original PCM.
Does this fit vehicles other than the 2004 Sierra 2500?
Yes, absolutely. This PCM fits a wide variety of 2004 GM trucks and SUVs, including the Silverado 1500/2500/3500, Tahoe, Suburban, Yukon, Escalade, Hummer H2, Envoy, Trailblazer, and more. Always confirm your original part or service number matches the ones listed in the description.