2006 Trailblazer PCM 19209820 Powertrain Control Module VIN Programmed

Is Your 2006 Trailblazer Driving You Crazy?

If you’re dealing with baffling issues like random stalling at stoplights, harsh or delayed transmission shifts, a check engine light that won’t go away, or even a complete no-start condition, the problem might not be what you think. After more than two decades turning wrenches and diagnosing these exact vehicles, I’ve seen countless owners replace perfectly good throttle bodies, sensors, and even transmissions, only to find the real culprit was the Powertrain Control Module (PCM).

The PCM is the brain of your Trailblazer’s engine and transmission. Located in the hot, vibrating environment of the engine bay, its delicate internal circuits are prone to failure over time. This can lead to a cascade of confusing symptoms that seem unrelated but all point back to this central computer.

Common Symptoms of a Failing 2006 Trailblazer PCM

If you’ve performed the checks above and are still experiencing problems, your PCM is the likely cause. Here are the classic signs I’ve diagnosed in my shop hundreds of times on these GMT360 platform vehicles (Trailblazer, Envoy, Rainier, etc.):

• ✔ Check Engine Light with communication error codes (like U0100) or multiple, seemingly random sensor codes.
• ✔ The engine cranks but refuses to start.
• ✔ Stalling for no reason, especially when coming to a stop or at idle.
• ✔ Extremely rough idle or poor engine performance.
• ✔ Transmission getting stuck in one gear (limp mode) or shifting erratically.
• ✔ Reduced Engine Power message on the dashboard.
• ✔ Inaccurate or non-functioning dashboard gauges.

The Guaranteed Solution: A VIN-Programmed PCM

This isn’t just a replacement part; it’s a complete solution. We take a quality PCM and flash it with the absolute latest GM-certified software calibration specifically for your vehicle. When you place your order, you provide us with your Vehicle Identification Number (VIN). This allows us to program the module to match your Trailblazer’s exact factory options—4×4, engine size, security system, and more. This eliminates compatibility guesswork and ensures a seamless installation.

This critical programming step means the module works right out of the box, resolving software bugs and performance issues that may have existed even when your truck was new. You get improved drivability and reliability without a trip to the dealership.

Simple Installation Process

Replacing the PCM is straightforward. It’s typically located on the driver’s side of the engine. After disconnecting the battery, you simply unplug the old module’s electrical connectors, unbolt it, and install the new one. Once installed, you will need to perform a simple security relearn procedure, which can be done without special tools and takes about 30 minutes. This syncs the new PCM with your vehicle’s anti-theft system.

Guaranteed Fitment and Part Number Compatibility

This module is a direct replacement for a wide range of original equipment part numbers. If your old module has one of the following numbers, this part is a 100% compatible replacement:

Compatible 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.

This PCM fits the following vehicles:

• ✔ 2006 Buick Rainier (4.2L)
• ✔ 2006 Chevrolet Trailblazer & Trailblazer EXT (4.2L)
• ✔ 2004-2006 Chevrolet Colorado
• ✔ 2006 GMC Envoy, Envoy XL (4.2L)
• ✔ 2004-2006 GMC Canyon
• ✔ 2006 Hummer H3
• ✔ 2006 Isuzu Ascender (4.2L)
• ✔ 2006 Isuzu i-280 & i-350
• ✔ 2006 Saab 9-7x (6-cylinder models)