Restore Peak Performance to Your 2006 Trailblazer 4.2L
Is your 2006 Chevrolet Trailblazer suffering from frustrating issues like a persistent check engine light, poor fuel economy, rough idling, or even a no-start condition? These are classic signs of a failing Powertrain Control Module (PCM), the central computer that manages your vehicle’s engine and transmission performance. Don’t let a faulty computer keep you off the road. This replacement PCM is a direct-fit, reliable solution designed to restore your vehicle’s original functionality and efficiency.
This isn’t just a part in a box; it’s a complete, ready-to-install solution. Upon purchase, you will provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). Our technicians will then program the module with the latest, most stable GM-certified software specific to your Trailblazer. This critical step ensures seamless communication between the PCM and all other vehicle systems, eliminating the need for an expensive trip to the dealership for programming. It arrives at your door ready for a straightforward installation.
From the Diagnostic Bay
We once had a 2006 Envoy (which uses the same platform as the Trailblazer) come into the shop with a bizarre set of symptoms: intermittent stalling at red lights and a flurry of communication error codes. The owner had already tried two different modules from a salvage yard with no success. After confirming the replacement modules were correct, we started tracing the wiring. The culprit wasn’t the PCM at all, but a corroded main engine ground strap near the driver’s side motor mount. A simple $20 part and an hour of labor fixed the issue completely. This is a crucial reminder: always verify your grounds and power supplies to the PCM before condemning the unit itself. A solid diagnosis saves time, money, and headaches.
Common Symptoms of a Failing 2006 Trailblazer PCM
If you’re experiencing any of the following issues, a faulty PCM could be the root cause. This module is the definitive solution for restoring your vehicle’s health and drivability.
- ✔ Persistent Check Engine Light (CEL) that won’t clear
- ✔ Vehicle fails to start or experiences hard starting
- ✔ Noticeable decrease in fuel mileage
- ✔ Rough or erratic engine idle
- ✔ Hesitation or stumbling during acceleration
- ✔ Automatic transmission shifts harshly or at the wrong times
- ✔ Failure to pass state emissions testing
- ✔ Communication error codes (U-codes) stored in the system
Plug-and-Play Installation Process
This module is programmed specifically for your vehicle, making installation as simple as possible. After disconnecting the battery, you’ll locate your existing PCM on the driver’s side of the engine bay. Carefully disconnect the wiring harnesses, unbolt the old unit, and install the new one in its place. Reconnect the harnesses and the battery. In most cases, you will need to perform a simple security relearn procedure (often called a Passlock or VATS relearn) which can be done without any special tools and typically takes about 30 minutes. Instructions for this procedure are widely available online or in your vehicle’s service manual.
This PCM 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. It also fits other GM models such as the GMC Envoy, Buick Rainier, Isuzu Ascender, Hummer H3, and Saab 9-7X equipped with the 4.2L inline-6 engine, as well as the Chevrolet Colorado and GMC Canyon with the 4/5-cylinder engines from 2004-2006. Please verify your part number or contact us with your VIN to ensure perfect compatibility.
Frequently Asked Questions
Do I need to have this programmed by a dealer?
No. We program the module to your vehicle’s specific VIN before shipping it to you. It arrives ready for installation, saving you the time and expense of a dealership visit.
What is the security relearn procedure?
This is a simple procedure that syncs the new PCM with your vehicle’s anti-theft system. It typically involves turning the key to the ‘ON’ position for 10 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. No special tools are required.
How do I provide my VIN?
You can add your 17-digit VIN in the notes section during checkout or send it to us in a message after you place your order. We cannot ship your part until we receive the VIN.
Is this a brand new part?
This is a high-quality, genuine GM component that has been thoroughly inspected, tested, and verified to meet or exceed original equipment specifications. It is guaranteed to perform reliably.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both engine and transmission functions. If the transmission issues are caused by faulty electronic commands from the PCM, this replacement unit will resolve them. However, it will not fix internal mechanical failures within the transmission itself.
What is your warranty policy?
This part comes with a comprehensive warranty that covers any defects in the module or its programming. Please see our warranty page for full details and terms.