Restore Your Vehicle’s Performance and Reliability
Is your Hummer H2, Silverado, Sierra, or other GM truck suffering from baffling electrical issues, poor performance, or a persistent check engine light? The Powertrain Control Module (PCM) is the brain of your vehicle, orchestrating everything from fuel injection and ignition timing to transmission shifting and emissions control. When it fails, it can cause a cascade of problems that are often difficult to diagnose, leading to frustration and costly, ineffective repairs. This replacement PCM, part number 12589463, is the definitive solution to restore your vehicle’s factory performance and operational integrity.
Unlike a generic part from a local store, this module is not just a piece of hardware; it’s a complete, ready-to-install solution. We flash the unit with the latest official GM software updates specifically calibrated to your vehicle’s Vehicle Identification Number (VIN). This critical step ensures seamless communication with all other onboard modules, correct engine and transmission parameters, and resolves software-related bugs that may have been present in your original unit. By providing us with your VIN upon purchase, you receive a module that is truly plug-and-play, saving you a trip to the dealership and expensive programming fees.
From the Diagnostic Bay
We had a 2005 Sierra 2500 with the 6.0L come in that was driving the owner crazy. The transmission was shifting harshly between 1st and 2nd gear, but only when warm. He had already replaced the transmission solenoids and fluid with no change. We scanned the vehicle and found no transmission-specific codes, only a generic communication error code that would come and go. After checking the wiring harness for damage, we suspected the PCM. The internal drivers that control the transmission solenoids can weaken over time, causing intermittent issues that don’t always set a hard code. We installed a VIN-programmed PCM, performed the security relearn, and the truck shifted like it just rolled off the assembly line. It’s a classic case of what seems like a major mechanical failure actually being an electronic one.
Common Symptoms of a Failing PCM
A faulty PCM can manifest in numerous ways. If you’re experiencing any of the following, your engine’s computer may be the culprit:
- ✔ Persistent Check Engine Light (CEL) with various trouble codes
- ✔ Rough or erratic engine idle
- ✔ Unexplained stalling or difficulty starting
- ✔ Poor fuel economy
- ✔ Harsh or delayed transmission shifting
- ✔ Failure to pass emissions testing
- ✔ Communication errors with diagnostic scan tools
- ✔ Random warning lights appearing on the dashboard
Why Choose Our Programmed Hummer H2 PCM?
Getting your vehicle back on the road shouldn’t be complicated. Our process is designed for both professional technicians and savvy DIYers. We handle the complex programming so you can focus on the installation. This module is a direct replacement for service numbers 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802, ensuring wide compatibility across a range of popular GM models including the Hummer H2, Chevrolet Avalanche, Silverado, Suburban, Tahoe, GMC Sierra, Yukon, and Cadillac Escalade. By installing our VIN-matched PCM, you are not just replacing a part; you are restoring the central nervous system of your vehicle with the most current and stable software available from the manufacturer.
Installation is straightforward. The PCM is typically located in the engine bay on the driver’s side, under the battery tray or next to the airbox. After disconnecting the battery, simply unplug the electrical connectors from the old unit, remove it, and install the new one. Once installed, you will need to perform a security relearn procedure (often called a CASE relearn or anti-theft relearn), which pairs the new module to your vehicle’s keys. This procedure is simple and can be done without special tools, typically taking about 30 minutes. Instructions are readily available online for your specific model.
Frequently Asked Questions
Do I need to have this PCM programmed by a dealer?
No. We program the module to your vehicle’s specific VIN before shipping it to you. This saves you the time, hassle, and expense of a dealership visit.
What is a security relearn and is it difficult?
A security relearn (or anti-theft relearn) syncs the new PCM with your vehicle’s security system. It’s a simple procedure that usually involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating this cycle three times. It requires no special tools and you can easily find instructions for your specific model online.
How do I provide my 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 correctly.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM or a software issue that the latest GM updates address, then yes, this will resolve the problem. However, if the light is on due to another failing sensor or component, that issue will still need to be addressed separately.
Is this part compatible with my vehicle?
This PCM fits a wide range of 2003-2007 GM trucks and SUVs. Please review the detailed fitment list on this page and ensure your vehicle is included. Matching the service number is also a great way to confirm compatibility.