Restore Peak Performance to Your 2004 GM Truck or SUV
Is your 2004 Cadillac Escalade EXT, Sierra, Silverado, or another compatible GM vehicle suffering from frustrating issues like a persistent check engine light, rough idling, stalling, or poor fuel economy? These are common indicators of a failing Powertrain Control Module (PCM). This replacement engine computer, part number 12586242, is the definitive solution to restore your vehicle’s factory performance, drivability, and reliability. We take the guesswork out of the repair by programming the module specifically to your vehicle’s VIN before it ships, ensuring a straightforward installation process.
From the Diagnostic Bay
We had a 2004 Sierra Denali in the shop with a laundry list of intermittent problems: random misfires, hard starting when warm, and occasional transmission shifting issues. The owner had already replaced the spark plugs, wires, and even a coil pack with no success. After hooking up our diagnostic scanner, we noticed communication dropouts with the PCM. Before condemning the module, we checked all the basics: battery voltage, ground connections (especially the main grounds on the engine block), and the integrity of the wiring harness. Everything checked out. Swapping in a known-good, VIN-programmed PCM like this one solved every single issue instantly. It’s a powerful reminder that the PCM is the brain of the vehicle, and when it fails, it can cause a cascade of confusing symptoms.
Common Symptoms of a Failing 2004 Escalade EXT PCM
- ✔ Check Engine Light: The most common sign, often with codes related to sensors, emissions, or internal module failure.
- ✔ No-Start or Hard Starting: The engine may crank but fail to start, or take an unusually long time to fire up.
- ✔ Poor Engine Performance: Noticeable loss of power, hesitation during acceleration, and rough running.
- ✔ Reduced Fuel Economy: The engine may run too rich or too lean, causing your fuel mileage to drop significantly.
- ✔ Erratic Shifting: The PCM also controls transmission functions, and a fault can lead to harsh or incorrect gear changes.
- ✔ Failed Emissions Test: A faulty PCM can prevent the vehicle’s emissions systems from operating correctly.
Plug-and-Play Solution with VIN Programming
Don’t waste time and money at the dealership. We provide a simple, effective solution. When you place your order, simply provide us with your vehicle’s 17-digit VIN. Our technicians will flash the module with the latest GM-certified software calibration specific to your vehicle. This ensures all factory settings for the engine, transmission, and other systems are perfectly matched. For most applications, this makes the unit ready for installation right out of the box. In some cases, a security relearn or a Crankshaft Variation (CASE) relearn may be required, which can be performed by a qualified technician with a compatible scan tool.
Guaranteed Compatibility
This PCM is a direct replacement for original equipment part number 12586242 and is also interchangeable with the following service numbers: 19299226, 89017738, YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, and YHTN. It is designed to fit a wide range of 2004 GM vehicles, including:
- Cadillac Escalade, ESV, EXT
- Chevrolet Avalanche, Silverado, Suburban, Tahoe, SSR, Trailblazer EXT
- GMC Sierra, Sierra Denali, Yukon, Yukon XL, Envoy XL, Envoy XUV
- Hummer H2
- Buick Rainier
- Isuzu Ascender
Please verify your original part number or service ID to ensure proper fitment for your specific application.
Frequently Asked Questions
Do I need to get this PCM programmed?
No. We handle the programming for you before we ship the part. Simply provide your vehicle’s VIN during checkout, and the module will arrive with the correct software for your specific vehicle, making installation much simpler.
What is a CASE relearn and will I need to perform one?
A CASE (Crankshaft Position System Variation) relearn is a procedure that allows the PCM to learn the minor variations in the crankshaft position sensor. This helps ensure accurate misfire detection. While not always necessary after a PCM replacement, if you have a persistent P0315 trouble code after installation, a CASE relearn will be required. This procedure must be done with a compatible high-end diagnostic scan tool.
Where is the PCM located on my 2004 Escalade EXT or Silverado?
On most of the compatible trucks and full-size SUVs like the Escalade, Silverado, Sierra, and Tahoe, the PCM is located in the engine bay on the driver’s side (LH front), under or next to the battery tray.
How do I provide my VIN for programming?
You can enter your 17-digit VIN in the notes section during the checkout process. If you forget, you can also reply to your order confirmation email with the VIN. We cannot ship the module until we receive this information.
Will this fix my vehicle’s specific problem?
This PCM is a direct solution for a faulty engine computer. While it resolves the many symptoms listed above, it’s crucial to ensure your vehicle has been properly diagnosed. A faulty PCM can mimic other issues, such as a bad sensor or wiring problem, so proper diagnosis is key.