Is Your 2006 GMC Envoy Acting Up? The PCM Might Be the Culprit.
The Powertrain Control Module, or PCM, is the central computer of your 2006 GMC Envoy. It manages everything from fuel injection and ignition timing to transmission shift points and emissions controls. When this critical component begins to fail, it can cause a wide range of frustrating and difficult-to-diagnose issues, leaving you with an unreliable vehicle. This replacement Powertrain Control Module is the definitive solution to restore your truck’s performance, reliability, and efficiency.
This isn’t just a generic part off a shelf. We program this module specifically for your vehicle using the VIN you provide. This critical step ensures that the computer has the correct software and calibrations for your Envoy’s specific engine, transmission, and options. It arrives loaded with the latest updates from GM, often correcting factory bugs and improving overall drivability. This VIN-specific programming makes installation straightforward, getting you back on the road faster.
From the Diagnostic Bay
We had a 2006 Trailblazer (which uses the same platform as the Envoy) come into the shop with a persistent P0171 code (System Too Lean). The owner had already replaced the mass airflow sensor, both oxygen sensors, and even the fuel pump based on advice from forums. The light always came back. After hooking up our professional scan tool, we noticed the short-term fuel trim data was erratic and unresponsive. We checked the power and ground connections to the PCM, which were solid. This led us to suspect the PCM itself. The internal driver responsible for interpreting the O2 sensor data was failing, causing the computer to miscalculate the fuel mixture. After installing a VIN-programmed PCM, the fuel trims stabilized immediately, and the P0171 code never returned. It’s a classic case of treating the cause, not just the symptoms.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) that won’t clear, often with communication (U-series) codes.
- ✔ Unexplained drop in fuel economy.
- ✔ Engine stalling, stumbling, or running rough at idle.
- ✔ Harsh, delayed, or erratic automatic transmission shifting.
- ✔ The vehicle cranks but refuses to start (no-start condition).
- ✔ Failure to pass state emissions inspections.
- ✔ Inaccurate or non-functioning gauges on the instrument cluster.
Why a VIN-Programmed 2006 Envoy Powertrain Control Module is Essential
Simply installing a used module from another vehicle will not work. Modern GM vehicles utilize a Vehicle Anti-Theft System (VATS) that locks the PCM to the original vehicle’s VIN. Our service eliminates this problem. By providing your VIN during checkout, you receive a module that is a direct-fit replacement, ready for installation. This process ensures all communication between the PCM, the Body Control Module (BCM), and other vehicle systems functions exactly as it did from the factory. You are getting a reliable, fully-vetted component with the most current software available for your specific vehicle, ensuring peak performance and longevity.
This module is a direct replacement for a wide range of GM part numbers, including: 12569773, 12588650, 12589311, 12589585, 12591647, 12591648, 12593531, 12593532, 12594430, 12594431, 12596783, 12596784, 12597521, 12597776, 12597777, 12600818, 12604438, 12604439, 12606369, 12606373, 12606374, 12606398, 12606399, 19209820, and 19209821.
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s 17-digit VIN. You can typically find it on your driver’s side dashboard (visible through the windshield), on your door jamb sticker, or on your vehicle’s registration and insurance documents. We cannot ship the module until we receive your VIN.
Is this a plug-and-play installation?
Yes, for most vehicles this is a direct plug-and-play part. Once you install the module, you may need to perform a security relearn procedure, which can often be done without special tools and takes about 30 minutes. We will include instructions for this simple procedure with your order.
What’s the difference between a PCM, ECM, and ECU?
These terms are often used interchangeably. ECM (Engine Control Module) typically only controls engine functions. ECU (Electronic Control Unit) is a generic term. PCM (Powertrain Control Module) is the most accurate term for this part, as it controls both the engine and the transmission functions in your GM vehicle.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM, then yes, this part will resolve the issue. However, it’s crucial to ensure your vehicle has been properly diagnosed. This module will not fix problems caused by other faulty sensors or mechanical issues.
Do I need to return my old module?
No core charge is required for this part. You do not need to send your old, non-functioning module back to us.
What other vehicles does this part fit?
This module also fits the 2006 Rainier, Hummer H3, Isuzu Ascender, Trailblazer, Envoy XL, Saab 9-7X, and 2004-2006 Colorado and Canyon, among others. Please verify the part number and vehicle options to ensure compatibility.