Restore Peak Performance to Your 2004 GM Truck or SUV
Is your 2004 GMC Yukon XL 1500 suffering from erratic behavior, a persistent check engine light, or frustrating no-start conditions? These are classic signs of a failing Powertrain Control Module (PCM). As the central brain of your vehicle, the PCM governs everything from fuel mixture and ignition timing to transmission shifting and emissions control. When it falters, the entire vehicle’s performance and reliability are compromised. This replacement PCM, part number 12586242, is the definitive solution to get your truck back on the road running like new.
We take the guesswork and hassle out of the repair process. Unlike sourcing a module from a salvage yard, which would require expensive dealer programming, this unit arrives at your door fully programmed to your vehicle’s specific Vehicle Identification Number (VIN). We load the latest GM-certified software updates, ensuring optimal performance, fuel economy, and emissions compliance. This means no extra trips to the dealership and no hidden fees—just a straightforward, effective repair.
From the Diagnostic Bay
We had a 2004 Sierra 1500 come into the shop with a laundry list of bizarre issues. The customer complained of random stalling at stoplights, harsh shifting, and a check engine light that multiple shops couldn’t permanently fix. After checking the basics, our scan tool revealed communication errors with the PCM. We swapped in one of our VIN-programmed 12586242 modules. After performing the simple security relearn procedure, the truck fired right up. On the test drive, the transmission shifted smoothly, the engine idled perfectly, and all the phantom codes were gone. It’s a reminder that a solid, correctly programmed PCM is the foundation of a well-running vehicle.
Symptoms of a Failing 2004 Yukon XL PCM
A faulty engine computer can manifest in numerous ways, often mimicking other component failures. If you’re experiencing any of the following, your PCM is a likely culprit. Replacing it can save you from chasing down incorrect diagnoses and replacing perfectly good parts.
- ✔ Check Engine Light: The module may set false trouble codes or fail to communicate with diagnostic scanners.
- ✔ Poor Fuel Economy: Incorrect fuel and air calculations lead to wasted gas and reduced MPG.
- ✔ Engine Stalling or Misfiring: The PCM may fail to properly control ignition timing or fuel injectors, causing rough running conditions.
- ✔ Harsh or Failed Transmission Shifting: The PCM controls transmission solenoids; a fault can cause erratic shifting or getting stuck in gear.
- ✔ No-Start Condition: The vehicle may crank but fail to start if the PCM isn’t activating the fuel pump or ignition system.
- ✔ Failed Emissions Test: An inability to properly manage the engine’s combustion process will lead to high emissions.
Plug-and-Play Installation
Our goal is to make your repair as simple as possible. Because we program the module with your VIN before shipping, installation is incredibly straightforward. Simply disconnect the battery, swap the old module with the new one, and reconnect the battery. For most 2004 GM vehicles, you will need to perform a security relearn procedure (often called a CASE relearn) which allows the new PCM to synchronize with your vehicle’s anti-theft system. This procedure is simple, requires no special tools, and typically takes about 30 minutes. Instructions are readily available online or in your vehicle’s service manual.
This PCM is a direct replacement for service number 12586242 and is also compatible with a wide range of other service numbers, including 19299226, 89017738, YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, and YHTN. It fits a vast array of 2004 GM models like the Sierra, Silverado, Escalade, Tahoe, Suburban, Hummer H2, and more, ensuring a perfect match for your vehicle’s needs.
Frequently Asked Questions
Do I need to have this PCM programmed?
No. We handle all the programming for you before shipment. Simply provide us with your vehicle’s VIN during or after checkout, and we will flash the module with the latest GM software specific to your vehicle. It will arrive ready for installation.
What is a security relearn procedure?
A security relearn, or CASE relearn, is a simple process that allows your vehicle’s anti-theft and security system to recognize the new PCM. It typically involves a sequence of turning the key in the ignition. It requires no special tools and is a necessary final step after installation.
Where is the PCM located on my 2004 Yukon XL?
On most full-size GM trucks and SUVs from this era, including the 2004 Yukon XL, the PCM is located in the engine bay on the driver’s side, under the battery tray or near the firewall.
Is this a new or used part?
This is a high-quality, inspected, and tested original equipment part that has been professionally programmed to ensure it meets or exceeds OEM specifications for performance and longevity.
How do I confirm this is the right part for my vehicle?
The best way is to match the service number on your current PCM to one of the numbers listed in this description, such as 12586242. Providing your VIN when you order also allows us to double-check and guarantee compatibility.