Restore Peak Performance to Your GM Truck or SUV
Is your 2006 Buick Rainier, Trailblazer, or Envoy suffering from frustrating issues like a persistent check engine light, poor fuel economy, erratic shifting, or even a no-start condition? These are classic signs of a failing Powertrain Control Module (PCM), the electronic brain of your vehicle. A faulty PCM can disrupt everything from fuel delivery to transmission control, making your vehicle unreliable and stressful to drive. Don’t let a bad computer keep you off the road. This is the direct, reliable solution you’ve been looking for.
We offer a professionally prepared PCM, part number 12569773, that arrives at your door programmed with the latest official GM software updates. We use your vehicle’s unique VIN to ensure the module is a perfect match for its specific configuration. This critical step eliminates the need for expensive dealership programming or specialized scan tools, putting the power of repair back in your hands. By installing this module, you’re not just replacing a broken part—you’re ensuring your engine and transmission operate exactly as the manufacturer intended, with all the latest performance and reliability improvements.
Case Study: A Tricky Diagnosis
I remember a 2006 Trailblazer with the 4.2L engine that came into my shop with a ghost of a problem. The owner reported it would randomly stall at red lights, but only after driving for 30+ minutes. There were no consistent trouble codes, just an occasional U0100 (Lost Communication with ECM/PCM). We checked all the usual suspects—grounds, wiring harnesses, and the CAN bus network—and everything looked perfect. On a hunch, I used a heat gun to carefully warm up the PCM while the engine was running. Sure enough, as the module’s temperature rose, the engine sputtered and died. The internal processor was failing under heat stress. Replacing the PCM with a properly programmed unit like this one solved the problem for good. It’s a reminder that sometimes the ‘brain’ itself is the source of the most confusing symptoms.
Common Signs of a Failing PCM
If you’re experiencing any of the following, a faulty PCM could be the culprit. This is especially true if you’ve already checked sensors and wiring. A failing computer can cause a wide range of issues that can be difficult to diagnose without simply replacing the unit.
- ✔ Check Engine Light is on with codes like P0601, P0606, or other internal processor faults.
- ✔ Vehicle refuses to start or starts and immediately stalls.
- ✔ Noticeable decrease in fuel mileage.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Engine misfires, stumbles, or runs rough.
- ✔ Communication errors with diagnostic scan tools.
A Straightforward Guide to Installation
Installing your new 2006 Rainier Powertrain Control Module is a manageable job for a DIYer with basic tools. The most important part is the security relearn procedure at the end, which is simple to perform.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait 10-15 minutes before beginning work.
- Locate the PCM: On 4.2L models like the Rainier, Trailblazer, and Envoy, the PCM is typically located on the driver’s side of the engine block. On models like the Colorado, Canyon, and H3, it’s usually mounted on the passenger-side firewall.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that need to be released. Once unplugged, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed PCM into place. Firmly reconnect the electrical connectors, ensuring they click and lock securely.
- Reconnect the Battery: Re-attach the negative battery terminal.
- Perform Security Relearn (Crucial Step): Do NOT attempt to start the engine yet. Turn the key to the ‘ON’ position (without starting) for 10-12 minutes. The ‘Security’ light on the dash should turn off. Turn the key ‘OFF’ for 10 seconds. Repeat this cycle two more times for a total of three 10-minute cycles. After the third cycle, the vehicle will have learned the new PCM and will start.
Verified Vehicle Compatibility
This module is a guaranteed fit for the following vehicles, replacing a wide range of original part numbers including 12569773, 12588650, 12591647, 12597521, and more. Please verify your vehicle is on this list before ordering.
- 2006 Buick Rainier (4.2L, LH Engine)
- 2006 Chevrolet Trailblazer & Trailblazer EXT (4.2L, LH Engine)
- 2004-2006 Chevrolet Colorado (RH Firewall)
- 2006 GMC Envoy, Envoy XL (4.2L, LH Engine)
- 2004-2006 GMC Canyon (RH Firewall)
- 2006 Hummer H3 (RH Firewall)
- 2006 Isuzu Ascender (4.2L, LH Engine)
- 2006 Isuzu i-280 & i-350 (RH Firewall)
- 2006 Saab 9-7X (6 Cylinder, LH Engine)
Why do you need my VIN number?
We require your Vehicle Identification Number (VIN) to program the module with the exact software and calibrations for your truck’s specific engine, transmission, and factory options. This ensures a perfect match and proper vehicle operation.
Is this module difficult to install at home?
No, the physical installation is straightforward. The most important part is performing the security relearn procedure correctly after installation, which involves a few key cycles. Our instructions walk you through this simple but critical process.
Will this fix my specific problem?
If your vehicle’s issues are caused by a faulty computer (e.g., internal processor codes, no-start, erratic behavior), this 2006 Rainier Powertrain Control Module is the definitive solution. It resolves the root cause of the electronic failure.
What happens after I place my order?
After you complete your purchase, we will reach out to you to request your vehicle’s VIN. Once we receive it, our technicians will program the module, and it will be shipped directly to you, ready for installation.
Are any other programming or dealer visits required?
No. Because we program the module to your VIN before shipping, you will not need to visit a dealer or mechanic for additional programming. This saves you time and hundreds of dollars in labor costs.