Restore Your Vehicle’s Performance and Reliability
Is your 2006 GMC Envoy, Chevy Trailblazer, or another compatible GM vehicle suffering from perplexing issues like a persistent check engine light, erratic shifting, poor fuel economy, or even a no-start condition? These are classic signs of a failing Powertrain Control Module (PCM), the central computer responsible for managing your engine and transmission. A faulty PCM can disrupt communication between critical systems, leading to a cascade of problems that can leave you stranded. This replacement PCM, part number 19209821, is the definitive solution to restore your vehicle’s factory performance and operational integrity.
This isn’t just a generic, off-the-shelf part. We provide a fully programmed module tailored specifically to your vehicle. Upon purchase, you simply provide us with your Vehicle Identification Number (VIN), and our technicians will flash the unit with the latest, most stable software updates directly from General Motors. This critical step ensures seamless integration with your vehicle’s existing systems, eliminating the need for an expensive trip to the dealership for programming. It’s designed to be a direct-fit, plug-and-play solution to get you back on the road quickly and confidently.
From the Diagnostic Bay
We had a 2006 Chevy Trailblazer with the 4.2L engine towed in last month. The owner was frustrated because it would crank but never start, and he had already replaced the fuel pump and crank sensor with no luck. The check engine light was on, but his basic scanner couldn’t communicate with the computer. We hooked up our professional diagnostic tool and found the same thing: no communication with the PCM. After verifying the PCM was receiving proper power and ground, we knew the module itself had failed internally. We installed one of these VIN-programmed PCMs, performed the security relearn procedure, and the truck fired up on the first try and ran perfectly. It’s a common failure point that can mimic many other problems.
Symptoms of a Failing 2006 Envoy PCM
- ✔ Check Engine Light: The most common symptom, often with communication error codes (U-codes) or codes for multiple unrelated sensors.
- ✔ Engine Performance Issues: Stalling, rough idling, hesitation during acceleration, misfires, or a noticeable drop in power.
- ✔ Poor Fuel Economy: The PCM controls the air-fuel mixture; a malfunction can cause the engine to run too rich, wasting fuel.
- ✔ Transmission Shifting Problems: Harsh shifting, delayed engagement, or getting stuck in one gear (limp mode) as the PCM also controls transmission functions.
- ✔ No-Start Condition: The engine may crank but will not start because the PCM isn’t firing the ignition coils or fuel injectors.
- ✔ Failed Emissions Test: A malfunctioning PCM can prevent the onboard diagnostic systems from running correctly, leading to an automatic failure.
The Importance of VIN Programming
The 2006 Envoy PCM is not a one-size-fits-all component. Each vehicle has unique parameters based on its specific options, emissions standards, and drivetrain. VIN programming ensures that the module you receive is an exact match for your vehicle’s original configuration. This process correctly sets up the anti-theft system (PassLock/VATS), transmission shift points, fuel delivery strategy, and dozens of other critical parameters. Installing a non-programmed module will, at best, result in poor performance and, at worst, prevent the vehicle from starting at all.
Installation and Setup
Physically replacing the PCM is straightforward. On most of these vehicles, it is located on the driver’s side of the engine compartment. Simply disconnect the battery, unplug the electrical connectors from the old module, unbolt it, and install the new one in its place. After reconnecting the battery, you will likely need to perform a security relearn procedure, also known as a VATS relearn. This procedure can typically be done without special tools and involves a sequence of key turns. Instructions for this are widely available online or in your vehicle’s service manual. In some cases, a Crankshaft Position Sensor Variation Relearn (CASE relearn) may be needed with a capable scan tool to prevent a P1336 trouble code, but the vehicle will run and drive without it.
Guaranteed Fitment
This module is a direct replacement for a wide range of GM trucks and SUVs. It is compatible with 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, and 19209821. Please verify your part number or contact us with your VIN to confirm compatibility before ordering.
Frequently Asked Questions
Is this module ready to install out of the box?
Yes, this module comes pre-programmed to the VIN you provide. After physical installation, you will only need to perform the vehicle’s security relearn procedure, which syncs the new PCM with your keys and anti-theft system.
Where do I find my VIN and how do I provide it?
Your 17-digit VIN can be found on your vehicle’s dashboard (visible through the driver’s side of the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents. You can provide the VIN to us during the checkout process or by responding to our post-purchase confirmation email.
Do I need to send my old PCM (core) back?
No core charge or return is required for this part. You can keep or recycle your old module at your convenience.
Will this fix my specific check engine light codes?
This PCM will resolve any trouble codes that are directly caused by an internal failure of the computer itself, such as internal processor faults or communication errors. However, if codes are being set due to faulty sensors or wiring on the vehicle, those external issues will still need to be addressed separately.
What tools are needed for installation?
Basic hand tools, such as a socket set, are all that’s needed to physically swap the module. No special programming tools are required from you, as we handle all the flashing before shipment.