Is Your 2006 Envoy XL Running Rough, Stalling, or Throwing Confusing Codes?
If you’re behind the wheel of a 2006 GMC Envoy XL, you know it’s a capable and comfortable SUV. But when the Powertrain Control Module (PCM) starts to fail, it can turn into a source of major frustration. As a technician with over two decades of experience, I’ve seen firsthand how a faulty PCM can mimic a dozen other problems, leading owners and even some shops on a wild goose chase replacing perfectly good sensors and parts.
The PCM is the brain of your vehicle’s engine and transmission. It controls everything from the fuel injectors and spark plugs to the shift points of your automatic transmission. When it begins to fail, the symptoms can be intermittent and maddening.
Common Symptoms of a Failing 2006 Envoy XL PCM
I’ve diagnosed hundreds of these GMT360 platform vehicles (Envoy, Trailblazer, Rainier, etc.), and the signs of a failing computer are often very consistent. You might be experiencing:
- โ Unexplained stalling, either at idle or while driving.
- โ Harsh or erratic automatic transmission shifting.
- โ A persistent Check Engine Light with codes that won’t clear or that point to multiple, unrelated sensors.
- โ No-start or hard-start conditions, especially when the engine is warm.
- โ Poor fuel economy and a noticeable loss of engine power.
- โ Communication errors when trying to connect a professional scan tool.
Expert Pro Tip: Check Your Grounds First!
Before you condemn your PCM, do yourself a favor and check the main engine and chassis ground connections. On these trucks, a corroded or loose ground can cause voltage issues that mimic PCM failure. I’ve seen customers save hundreds by simply cleaning the ground strap connection near the battery or on the engine block. A few minutes with a wire brush can sometimes solve intermittent electrical gremlins. If your grounds are clean and tight and the problems persist, the PCM is the most likely culprit.
The Solution: A Reliable, Pre-Programmed PCM
This Powertrain Control Module is the definitive solution to get your Envoy XL running properly again. This isn’t just a part in a box; it’s a comprehensive service. We take the hassle and high cost of dealership programming out of the equation. When you order, you provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). Our technicians then flash this module with the latest, most stable software updates directly from GM for your specific vehicle configuration.
This process ensures that the module communicates perfectly with your Envoy XL’s other systems, restoring factory performance and efficiency. It arrives at your door ready for installation, saving you a tow to the dealer and hundreds in programming fees.
Installation & What to Expect
For the 2006 Envoy XL with the 4.2L engine, the PCM is located on the driver’s side (LH) of the engine block. Installation is straightforward for a DIYer with basic tools:
- Disconnect the Battery: Always disconnect the negative battery terminal before working on any electronic components.
- Locate and Remove: Unplug the electrical connectors (they have locking tabs) and unbolt the old module from its bracket.
- Install the New Module: Bolt the new PCM into place and securely reconnect the color-coded connectors.
- Reconnect Battery: Reattach the negative battery terminal.
In most cases, the vehicle will start and run immediately. You may need to perform a Crankshaft Position System Variation Learn procedure (often called a CASE relearn) with a compatible scan tool to clear a P1336 code and ensure optimal engine timing, but the core engine and transmission functions will be restored right out of the box.
Guaranteed Compatibility
This module is a direct replacement for a wide range of GM trucks and SUVs from this era. It is compatible with numerous part numbers, ensuring a perfect fit if your old module carries any of the following identifiers:
Part Numbers: 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.
This part will fit these makes and models with these options:
- โ 2006 ENVOY & ENVOY XL (4.2L Engine)
- โ 2006 TRAILBLAZER & TRAILBLAZER EXT (4.2L Engine)
- โ 2006 BUICK RAINIER (4.2L Engine)
- โ 2006 ISUZU ASCENDER (4.2L Engine)
- โ 2006 SAAB 9-7X (6 Cylinder)
- โ 2004-2006 CHEVROLET COLORADO
- โ 2004-2006 GMC CANYON
- โ 2006 HUMMER H3
- โ 2006 ISUZU I-280 & I-350