Restore Peak Performance to Your GM SUV
Is your Isuzu Ascender, Chevy Trailblazer, or GMC Envoy suffering from frustrating and unpredictable issues? A faulty Powertrain Control Module (PCM) is often the culprit behind a wide range of problems, from a persistent Check Engine Light to a vehicle that refuses to start. The PCM is the central computer, the brain of your engine and transmission, and when it fails, it can cause chaos. This replacement PCM, part number 12574976, is the definitive solution to get your vehicle running reliably again. We take the guesswork and hassle out of the repair by programming the module specifically to your vehicle’s Vehicle Identification Number (VIN) before it ships. This ensures a seamless, plug-and-play installation without requiring an expensive trip to the dealership.
From the Diagnostic Bay
We had a 2004 Chevy Trailblazer come into the shop with what the owner was convinced was a failing transmission. It was shifting erratically, sometimes getting stuck in gear, and throwing a handful of confusing codes. He had already spent a small fortune at a transmission shop that couldn’t pinpoint the issue. After hooking up our professional scan tool, we noticed that the communication between the PCM and the Transmission Control Module (TCM) was intermittent. Instead of a mechanical failure, it was an electronic one. The PCM’s internal drivers for the transmission circuits were failing. We installed a VIN-programmed PCM just like this one, performed a quick security relearn, and the truck drove like it just rolled off the assembly line. It saved the customer thousands on an unnecessary transmission rebuild and solved a problem that had plagued him for months.
Is Your Vehicle Showing These Symptoms?
- ✔ Persistent Check Engine Light (CEL) with various trouble codes
- ✔ Engine stalling, stumbling, or running rough at idle
- ✔ Vehicle refuses to start or has intermittent starting issues
- ✔ Noticeable decrease in fuel economy
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Failure to pass state emissions tests
- ✔ Communication errors with diagnostic scan tools
The Superior Solution: A VIN-Programmed Module
Many replacement modules require complex and costly programming at a dealership after installation. Our process eliminates that step entirely. When you provide us with your vehicle’s VIN, our technicians flash the module with the latest, most stable software updates directly from GM. This ensures that all factory settings, security protocols (like VATS or Passlock), and performance parameters are perfectly matched to your specific vehicle configuration. This is not a generic, one-size-fits-all solution; it’s a precise component prepared for your SUV. This attention to detail guarantees optimal engine performance, fuel efficiency, and transmission function right out of the box.
Guaranteed Fitment for Your 2003-2005 Isuzu Ascender PCM and More
This module is a direct replacement for a wide range of popular GM SUVs built on the GMT360 platform. While this is the core computer for the 2003-2005 Isuzu Ascender PCM, it is also fully compatible with numerous other models. Please verify your original part number against our cross-reference list to ensure a perfect match. This unit replaces part numbers including 12573576, 12574976, 12577955, 12584593, 16255757, and 19210065. It fits the 4.2L 6-cylinder engine in models such as:
- Chevrolet Trailblazer & Trailblazer EXT (2003-2005)
- GMC Envoy, Envoy XL, & Envoy XUV (2003-2005)
- Buick Rainier (2004-2005)
- Oldsmobile Bravada (2003-2004)
- Isuzu Ascender (2003-2005)
- Saab 9-7X (2005-2006)
Frequently Asked Questions
Do I need to have this computer programmed by a dealer?
No. We program the computer to your vehicle’s specific VIN before we ship it to you. This means it will arrive ready for installation without the need for any additional programming from a dealership, saving you time and money.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit VIN. You can typically find this on your vehicle’s dashboard (visible through the windshield on the driver’s side), on your vehicle registration, or on your insurance card.
Where is the PCM located on my vehicle?
On most GMT360 platform vehicles like the Trailblazer, Envoy, and Ascender, the PCM is located in the engine bay, on the driver’s side, near the firewall and brake master cylinder. It is a silver metal box with several large electrical connectors.
Will this fix my Check Engine Light?
If the Check Engine Light is on due to a faulty PCM, then this part will resolve the issue. However, it’s crucial to properly diagnose the vehicle first, as the light can be triggered by many other components, such as a bad oxygen sensor or a loose gas cap. This module will fix codes specifically related to internal processor failure or driver circuit faults.
Is any special procedure needed after installation?
In many cases, the vehicle will start and run perfectly after installation. However, some GM vehicles may require a simple security relearn procedure, also known as a VATS or Passlock relearn. This procedure can be done without any special tools and typically involves cycling the ignition key. Instructions are widely available online or can be provided upon request.