Restore Your Truck’s Performance and Reliability
Is your 2006 Trailblazer EXT suffering from baffling electrical gremlins? Issues like intermittent stalling, a persistent Check Engine Light, poor fuel economy, or a complete no-start condition can often be traced back to a single component: a failing Powertrain Control Module (PCM). As the central computer, the PCM is the brain of your vehicle, managing everything from fuel injection and ignition timing to transmission shifting. When it starts to fail, it can cause a cascade of frustrating and hard-to-diagnose problems.
This isn’t just a replacement part; it’s a complete solution. We provide a high-quality PCM that is professionally programmed with the latest GM factory software updates, tailored specifically to your vehicle’s Vehicle Identification Number (VIN). This critical step ensures seamless communication between the new module and all other systems in your truck, restoring its original performance and efficiency. Forget the expensive trip to the dealership for programming—this module is prepared for installation right out of the box.
From the Diagnostic Bay: The Intermittent Stall Case
I remember a 2006 Envoy—which uses this exact same PCM—that came into my shop with an issue that was driving the owner crazy. It would run perfectly for days, then suddenly stall at a stoplight and refuse to restart for 10-15 minutes. No consistent codes were stored, just a few random communication errors. After checking all the usual suspects like the crank sensor and fuel pump, I focused on the PCM. On these GMT360 platform vehicles, the PCM is located in the engine bay where it endures thousands of heat cycles. Over time, these temperature swings can cause microscopic cracks in the internal circuit board solder joints. When the engine was hot, a connection would separate, causing the stall. Once it cooled slightly, the connection was restored. Swapping in a properly programmed PCM solved the problem for good. It’s a classic failure I’ve seen dozens of times on these trucks.
Why a Pre-Programmed 2006 Trailblazer EXT PCM is the Smart Choice
Choosing a module that is pre-programmed to your VIN saves you significant time, money, and hassle. A blank module from a dealer or parts store would require towing your vehicle to a facility with a GM Tech 2 or equivalent scan tool, costing you hundreds in labor and programming fees. Our process handles the complex part for you. Simply provide your VIN during checkout, and we’ll ensure the module is a perfect match for your vehicle’s specific configuration.
Common Signs of a Failing PCM
- ✔ Check Engine Light is on with codes like P0601, P0602, P0606 (Internal Control Module errors)
- ✔ Engine stalls, stumbles, or misfires intermittently
- ✔ Vehicle will not start, but the battery and starter are good
- ✔ Noticeable decrease in fuel economy
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Communication errors with your scan tool
Plug-and-Play Installation: Get Back on the Road Fast
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery.
- ✔ Locate the PCM: On most 4.2L Trailblazers, Envoys, and Ascenders, the PCM is mounted on the driver’s side of the engine block, below the intake manifold. On Colorado, Canyon, and H3 models, it’s typically on the passenger-side firewall.
- ✔ Disconnect the Connectors: Carefully unclip the wire harness connectors from the old module. Inspect them for any corrosion or damage.
- ✔ Remove the Old Module: Unbolt the old PCM from its mounting bracket.
- ✔ Install the New Module: Mount your new, pre-programmed PCM and securely reconnect the wire harnesses.
- ✔ Reconnect the Battery: Reattach the negative battery terminal.
- ✔ Perform Security Relearn: You will need to perform a simple security relearn procedure (often called a Passlock relearn) so the vehicle recognizes the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times before starting the engine.
Verified Vehicle Compatibility
This Powertrain Control Module is a direct fit for the following vehicles. Please match your part number or contact us with your VIN to confirm compatibility.
- Buick Rainier: 2006 (4.2L)
- Chevrolet Colorado: 2004-2006
- Chevrolet Trailblazer & Trailblazer EXT: 2006 (4.2L)
- GMC Canyon: 2004-2006
- GMC Envoy & Envoy XL: 2006 (4.2L)
- Hummer H3: 2006
- Isuzu Ascender: 2006 (4.2L)
- Isuzu i-280: 2006
- Isuzu i-350: 2006
- Saab 9-7x: 2006 (6-Cylinder)
This module replaces part numbers: 12569773, 12588650, 12589311, 12589585, 12591647, 12591648, 12593531, 12593532, 12594430, 12594431, 12596783, 12596784, 12597521, 12597776, and more.
Frequently Asked Questions
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, you will receive instructions on where to send your vehicle’s 17-digit VIN. We cannot ship your order until we receive this information.
Is this part truly plug-and-play?
Yes, it comes programmed and ready for installation. The only additional step required is a simple security relearn procedure that you can do yourself in about 30 minutes with just your car key. Instructions are widely available online for this common GM procedure.
Will this fix my specific problem?
This module corrects issues directly caused by a faulty PCM. While it resolves the most common symptoms like stalling and specific internal failure codes (P0601-P0606), it’s essential to ensure your vehicle has been properly diagnosed. This part will not fix problems related to other bad sensors or mechanical failures.
What if my original part number is not 12597521?
This module is a direct replacement for a long list of interchangeable GM part numbers. As long as your vehicle, year, and engine are on our compatibility list, this module will work. The VIN programming ensures it functions correctly for your specific application.