Is Your 2006 GMC Envoy XL Running Rough? The PCM Might Be the Culprit.
If you’re dealing with frustrating and unpredictable issues like a persistent Check Engine Light, poor fuel economy, erratic shifting, or even a no-start condition in your 2006 GMC Envoy XL, a failing Powertrain Control Module (PCM) is a very likely cause. As the central computer for your vehicle’s engine and transmission, the PCM is responsible for managing everything from fuel injection and ignition timing to transmission shift points and emissions controls. When it starts to fail, it can create a cascade of problems that are often difficult to diagnose.
This replacement Powertrain Control Module is the definitive solution to get your vehicle running reliably again. We take the guesswork and high dealership costs out of the equation. Simply provide us with your vehicle’s VIN during checkout, and we will program the module with the latest, most up-to-date software directly from GM. This ensures perfect compatibility and optimal performance, tailored specifically for your Envoy XL. It arrives at your door ready for installation, saving you a trip to the dealer and the expensive programming fees they charge.
From the Diagnostic Bay
We had a 2006 Trailblazer (the Envoy’s sibling) come into the shop with a complaint of harsh, delayed shifting and a random engine stall at idle. The customer had already replaced the transmission fluid and filter, and even a few sensors, with no luck. The Check Engine Light was on, but the codes were intermittent and pointed in multiple directions—a classic sign of a confused computer. After confirming the wiring harness and grounds were solid, we focused on the PCM. We swapped in one of our pre-programmed modules, performed the quick security relearn, and took it for a drive. The difference was immediate. Shifts were smooth, the idle was stable, and all the ghost-like codes were gone. It’s a reminder that sometimes the root cause isn’t a mechanical part, but the brain that controls it.
Symptoms of a Failing 2006 Envoy XL PCM
- ✔ Persistent Check Engine Light (CEL) with various or inconsistent trouble codes.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Rough or unstable engine idle.
- ✔ Harsh, delayed, or erratic automatic transmission shifting.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ The vehicle cranks but refuses to start.
- ✔ Failure to pass state emissions testing.
- ✔ Communication errors with diagnostic scan tools.
The Plug-and-Play Solution
Replacing the brain of your vehicle sounds intimidating, but we make it simple. Because this unit is pre-programmed for your specific VIN, the most complex part of the job is already done. Installation typically involves disconnecting the battery, unplugging the electrical connectors from the old PCM, unbolting it from its mounting location (on the driver’s side of the engine compartment), and installing the new one in its place. After installation, you will need to perform a security relearn procedure (often called a CASE relearn or Passlock relearn) to synchronize the new module with your vehicle’s anti-theft system and crankshaft position sensor. This procedure can often be done without special tools, or with a capable bi-directional scan tool.
Guaranteed Compatibility
This module is a direct replacement for a wide range of GM vehicles and part numbers, ensuring a perfect fit and function. It is compatible with the 4.2L inline-6 engine found in the 2006 Envoy XL, Envoy, Trailblazer, Trailblazer EXT, Rainier, and Isuzu Ascender, as well as other GM trucks like the Colorado, Canyon, and Hummer H3. This module replaces the following 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, 19209821. Restore the reliability and performance of your truck with this dependable, VIN-programmed 2006 Envoy XL PCM.
Frequently Asked Questions
Do I need to get this PCM programmed by a dealer?
No. This is the biggest benefit of our service. We program the module to the specific VIN you provide before shipping it to you. It arrives ready to be installed, flashed with the latest GM software updates for your vehicle.
What is a ‘CASE Relearn’ and is it required?
A CASE (Crankshaft Angle Sensor Error) relearn is a procedure that synchronizes the new PCM with your engine’s crankshaft position sensor. This is required after installation for proper engine operation and to clear certain diagnostic trouble codes. This procedure can be completed with a compatible high-end scan tool or by a qualified mechanic.
Where is the PCM located on my 2006 Envoy XL?
On the 2006 GMC Envoy XL with the 4.2L engine, the Powertrain Control Module is typically located in the engine bay, on the driver’s side (LH side), mounted to the inner fender or firewall area.
How do I provide you with my vehicle’s VIN?
After you complete your purchase, you can add your VIN in the notes section of the order or reply to your order confirmation email with the 17-digit VIN. We cannot ship your part until we receive this information.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls the transmission’s electronic solenoids and shift logic. If the module is failing, it can cause erratic and harsh shifting. While it’s not a guarantee for all transmission issues, a faulty PCM is a very common cause of these symptoms in these vehicles.