Restore Peak Performance to Your GM SUV or Truck
Is your 2006 GMC Envoy XL, Trailblazer, or Hummer H3 suffering from frustrating and hard-to-diagnose issues? A faulty Powertrain Control Module (PCM) is often the hidden culprit behind a check engine light that won’t go away, erratic engine behavior, or poor transmission shifting. As a technician with over two decades of experience, I’ve seen how a failing PCM can disrupt the entire vehicle. This isn’t just a part; it’s the brain of your engine and transmission, and when it falters, everything feels off. This replacement 2006 Envoy XL PCM is the definitive solution to restore your vehicle’s reliability and drivability.
We take the guesswork and hassle out of the repair. Simply provide us with your vehicle’s VIN during checkout, and our experts will program this module with the latest, most stable software updates directly from GM. This means it arrives at your door ready for a straightforward installation, saving you a costly trip to the dealership for programming. It’s a direct-fit replacement for part number 19209821 and many others, ensuring a perfect match for your vehicle’s specific systems.
Case Study: A Tricky Diagnosis
A customer brought in a 2006 Trailblazer 4.2L with an intermittent no-start and a random stalling problem that no one could figure out. The fuel pressure was good, the crank sensor was new, but the symptoms persisted. After scanning, I found a stored P0601 (Internal Control Module Memory Check Sum Error) code that would only appear occasionally. Experience told me this pointed to the PCM itself failing internally, especially when heat-soaked. We installed one of our VIN-programmed PCMs, performed a quick security relearn, and the truck ran perfectly. The customer was thrilled to have his reliable vehicle back without spending a fortune on diagnostics.
Is Your Vehicle Showing These Signs of PCM Failure?
A failing PCM can cause a wide range of symptoms. If you’re experiencing any of the following, this module is likely the solution you need:
- ✔ Persistent Check Engine Light (CEL)
- ✔ Diagnostic Trouble Codes (DTCs) such as P0601, P0606, or other U-series communication codes.
- ✔ Vehicle won’t start or has difficulty starting.
- ✔ Poor or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ Engine stalling, sputtering, or misfiring for no apparent reason.
- ✔ Failure to pass an emissions inspection.
Your Straightforward Installation Guide
Replacing the PCM on these GM models is a job most DIYers can handle. For the 4.2L engine found in the Envoy, Trailblazer, and Rainier, the PCM is conveniently located. Here’s a general guide:
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the PCM: On models with the 4.2L I6 engine, you’ll find the PCM on the driver’s side of the engine compartment, mounted to the engine block. For models like the Colorado, Canyon, and H3, it’s typically on the passenger-side firewall.
- Disconnect the Connectors: Carefully unlatch and remove the electrical connectors from the old module. There are typically two or three large multi-pin connectors.
- Remove the Old Module: Unbolt the PCM from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed PCM into place.
- Reconnect Everything: Firmly plug the electrical connectors into the new PCM until they click and lock. Reconnect the negative battery terminal.
- Perform Security Relearn: You may need to perform a simple security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes. This allows the new PCM to synchronize with your vehicle’s anti-theft system.
Verified Vehicle Compatibility
This module is guaranteed to be a direct replacement for the specified part numbers and is compatible with the following vehicles. Please verify your model and engine options.
- 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 models)
This unit replaces a wide range of original part numbers, including: 12569773, 12588650, 12589311, 12589585, 12591647, 12596783, 12597521, 12600818, 19209820, and 19209821.
Frequently Asked Questions
Do I need to do any programming after I receive this part?
No. This module comes fully programmed to your vehicle’s VIN with the latest GM software. It is ready for installation right out of the box, though a simple security relearn procedure may be required.
Where is the PCM located on my 2006 Envoy XL?
On the 2006 Envoy XL with the 4.2L engine, the Powertrain Control Module (PCM) is mounted on the driver’s side of the engine block.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). We cannot ship your order until we receive this information for programming.
What is a security relearn?
It’s a simple, key-on procedure that synchronizes the new PCM with your vehicle’s anti-theft system. It typically takes about 10-15 minutes and does not require any special tools. Instructions are widely available online or in service manuals.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the PCM (like code P0601), then yes, this part is the correct fix. It is crucial to properly diagnose the vehicle first to ensure the PCM is the root cause of the issue.
Is this a brand new part?
This is a professionally inspected and tested original equipment part that has been programmed with new, updated software from GM. It provides the same reliability and function as a new dealer part.