Restore Peak Performance to Your GM Vehicle
Is your 2004 Buick Rainier, Chevy Silverado, GMC Sierra, or other GM truck/SUV suffering from perplexing engine problems? Issues like a persistent check engine light, rough idling, stalling, or poor fuel economy often point to a failing Powertrain Control Module (PCM), the central computer of your vehicle. This replacement PCM, service number 12586242, is the definitive solution to restore your vehicle’s factory performance, drivability, and reliability.
Unlike a generic part from a local store, this module is not just a piece of hardware. It’s a complete solution. Upon purchase, we require your vehicle’s Vehicle Identification Number (VIN) to program the unit with the latest, most up-to-date software directly from General Motors. This critical step ensures that the computer is perfectly matched to your vehicle’s specific configuration, including its engine, transmission, and emissions equipment. The result is a simple, plug-and-play installation without the need for an expensive trip to the dealership for programming.
From the Diagnostic Bay
We had a 2004 Sierra 1500 come into the shop with a classic complaint: intermittent stalling at red lights and a check engine light that previous mechanics couldn’t solve. The owner had already replaced the throttle body and two oxygen sensors based on the trouble codes. After hooking up our professional scan tool, we noticed erratic data from multiple sensors, but they all tested fine individually. This pointed to a processing issue within the PCM itself. Instead of throwing more parts at it, we installed a VIN-programmed 2004 Rainier PCM (the same 12586242 module) and performed a CASE relearn. The truck immediately ran smoothly, the codes cleared, and the customer was thrilled to finally have a reliable vehicle again. It’s a powerful reminder that sometimes the issue lies with the brain, not the limbs.
Symptoms of a Failing GM 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 could be the culprit:
- ✔ Persistent Check Engine Light (CEL) illumination
- ✔ Stored diagnostic trouble codes (DTCs) related to computer memory or processor faults
- ✔ Unexplained drops in fuel efficiency
- ✔ Engine stalling, stumbling, or hesitating during acceleration
- ✔ Harsh or erratic automatic transmission shifting
- ✔ The vehicle cranks but refuses to start
- ✔ Failure to pass state emissions inspections
Guaranteed Compatibility and Simple Installation
This module is a direct replacement for a wide range of 2004 General Motors vehicles. It is compatible with original equipment service numbers 12586242, 19299226, 89017738 and broadcast codes such as YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, and YHTN. It fits models including the Chevy Silverado, Suburban, Tahoe, Avalanche, SSR, Trailblazer EXT; the GMC Sierra, Yukon, Envoy XL/XUV; the Cadillac Escalade; the Hummer H2; the Buick Rainier; and the Isuzu Ascender. Please verify your original part number or service ID to ensure a perfect match.
Because we handle the programming, installation is straightforward for any DIY mechanic or professional technician. Simply disconnect the battery, swap the modules, and reconnect the battery. In most cases, you will need a capable scan tool to perform a security relearn (Passlock/VATS) and a Crankshaft Variation Relearn (CASE relearn) to ensure optimal performance and prevent starting issues.
Frequently Asked Questions
Is this PCM ready to install when it arrives?
Yes, the module arrives fully programmed with the latest GM software for your specific VIN. However, after installation, you will need to perform a security relearn and a CASE relearn procedure for the vehicle to start and run correctly. Most automotive shops can perform this in minutes.
Where do I provide my vehicle’s VIN?
After you complete your purchase, you can send us a message with your 17-digit VIN. We cannot ship your order until we receive this information, as the programming is essential for the part to function.
What is a CASE Relearn?
A Crankshaft Variation Relearn, or CASE relearn, is a procedure that allows the new PCM to learn the specific tolerances of your engine’s crankshaft position sensor. This is necessary for accurate misfire detection and smooth engine operation. It requires a compatible bi-directional scan tool.
Will this fix my vehicle’s problem?
This PCM will correct any issues directly caused by a faulty engine computer. While the symptoms listed are common for PCM failure, it’s always recommended to have a proper diagnosis performed by a qualified technician to rule out other potential causes like wiring or sensor faults.
How do I find my original part number?
Your vehicle’s original part number or service ID is printed on a sticker on the PCM itself. The location varies by model; it’s often next to the airbox (on Trailblazer/Envoy platforms) or under the battery tray on the driver’s side (on full-size trucks/SUVs).