Restore Peak Performance to Your GM Truck or SUV
Is your 2006 GMC Envoy XL suffering from baffling electrical gremlins? Issues like random stalling, a persistent check engine light, harsh shifting, or a complete no-start condition can often be traced back to a single, critical component: the Powertrain Control Module (PCM). As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing PCM can turn a reliable vehicle into a source of constant frustration. This isn’t just a part; it’s the central command center for your engine and transmission, and when it falters, the entire vehicle suffers.
This listing is for a direct-fit 2006 Envoy XL PCM, a robust solution designed to get you back on the road with confidence. We take the guesswork and hassle out of the repair. Before this module ships, we program it with the latest official GM software updates, specifically matched to your vehicle using its unique VIN. This eliminates the need for expensive dealership programming or specialized scan tools, making it a true plug-and-play fix for both seasoned mechanics and determined DIYers.
Case Study: A Tricky Diagnosis
A customer brought in a 2006 Trailblazer with the 4.2L engine—a sibling to the Envoy XL—that had every shop in town stumped. It had an intermittent no-crank condition and threw a dozen random communication codes (U-codes). We checked grounds, wiring, and the ignition switch, all of which tested fine. After hooking up a scope, we saw a noisy data line originating from the PCM. Even though the primary PCM failure codes (like P0601) weren’t present, the module was corrupting the vehicle’s communication network. Swapping in a pre-programmed PCM like this one solved the problem instantly. It’s a powerful reminder that PCM failure isn’t always obvious, but a quality replacement is often the definitive cure.
Is Your Vehicle Exhibiting These PCM Failure Signs?
A faulty engine computer can manifest in numerous ways. If you’re experiencing any of the following, a failing PCM is a likely culprit:
- ✔ Check Engine Light is on with codes like P0601, P0606, or other internal processor faults.
- ✔ Vehicle will not start, or it starts and immediately stalls.
- ✔ Loss of communication with the diagnostic scan tool.
- ✔ Erratic or harsh automatic transmission shifting.
- ✔ A significant, unexplained drop in fuel economy.
- ✔ Intermittent stalling or hesitation while driving.
- ✔ Failure to pass a state emissions inspection.
A Straightforward Guide to Installation
Installing your new 2006 Envoy XL PCM is a manageable job for anyone with basic tools. Follow these steps for a successful replacement.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
- Locate the PCM: On most 4.2L models like the Envoy and Trailblazer, the PCM is located on the driver’s side of the engine block. It’s a silver box with multiple large wiring harness connectors.
- Disconnect the Harnesses: Carefully release the locking tabs on each electrical connector and pull them straight out from the module. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. There are typically two or three bolts holding it in place.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and tighten the bolts securely.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Needed): In many cases, you will need to perform a simple security relearn procedure. Turn the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds. Repeat this cycle three times. On the fourth try, the vehicle should start.
Verified Vehicle Compatibility
This module is a guaranteed fit for a wide range of GM vehicles. Please verify your model and options below. This unit replaces part numbers including 12569773, 12588650, 12591647, 12597521, 12606399, and many more listed in the initial description.
- 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 & i-350: 2006
- Saab 9-7X: 2006 (6-Cylinder)
Frequently Asked Questions
How do I provide my VIN?
After completing your purchase, simply reply to your order confirmation email with your 17-digit Vehicle Identification Number (VIN). We cannot program and ship the module without it.
Is any additional programming required after installation?
No. This PCM arrives pre-programmed to your VIN with the latest GM software. In most cases, you will only need to perform a simple key/security relearn procedure, which does not require any special tools.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the old PCM (e.g., code P0601), this replacement module will solve the issue. However, if the light is on for another reason (like a bad oxygen sensor), that separate issue will still need to be addressed.
My original part number isn’t 12569773, but it’s on the cross-reference list. Will this work?
Yes. GM often uses many different part numbers for the same component over its production life. As long as your vehicle is listed in the compatibility chart, this module is the correct replacement, programmed specifically for your VIN.
What is the benefit of having the newest updates from GM?
GM frequently releases software updates to address factory bugs, improve transmission shifting logic, enhance fuel efficiency, and resolve other drivability issues that were discovered after the vehicle was built. Your new PCM will have these improvements built-in.