Is Your 2006 Trailblazer EXT Running Rough? Let’s Talk Solutions.
As a technician with over two decades of experience under the hood, I’ve seen my share of baffling electrical issues. One of the most common vehicles to roll into my bay with a list of strange symptoms is the GMT360 platform, which includes your 2006 Trailblazer EXT. The owner often reports a frustrating combination of problems: a persistent Check Engine Light, the engine cranking but not starting, harsh or delayed transmission shifts, or even random stalling at stoplights. If this sounds familiar, the root cause is very likely a failing Powertrain Control Module (PCM).
The PCM is the central computer, the ‘brain,’ that manages everything from fuel injection and ignition timing to transmission shift points and emissions controls. When it starts to fail, it can send the entire vehicle into a state of confusion, throwing a mix of seemingly unrelated diagnostic trouble codes (DTCs) and causing significant drivability problems.
Expert Pro Tip: Check Your Grounds First
Before you condemn the PCM, I always tell my customers and apprentice techs to do one thing: verify all power and ground connections to the module. On these Trailblazers, the main ground point on the engine block can corrode over time, causing intermittent voltage drops that mimic a bad PCM. Grab a multimeter, set it to DC volts, and check for a solid ground (less than 0.1 volts) between the PCM ground wires and the battery negative terminal. A 15-minute check can save you from replacing a perfectly good part. If the grounds are solid and the symptoms persist, the PCM itself is the next logical step.
The Dealership-Free Solution: Programmed & Ready to Install
Traditionally, replacing a PCM was a major headache. You’d buy the part, install it, and then have your vehicle towed to a dealership for expensive programming. Without this programming, the vehicle won’t start because the anti-theft system (Passlock/VATS) won’t recognize the new module. We’ve eliminated that entire process. This Powertrain Control Module is the definitive solution, arriving at your door already programmed with the latest GM-certified software specifically for your vehicle.
All we need is your vehicle’s 17-digit VIN (Vehicle Identification Number) during checkout. Our certified technicians will use your VIN to flash the module, ensuring it’s a perfect match for your Trailblazer’s specific configuration. This makes the installation process straightforward, saving you time, money, and the hassle of a dealership visit.
What You Get With This PCM:
- โ A reliable, tested Powertrain Control Module.
- โ Programmed to your exact VIN with the newest GM software updates.
- โ Corrects common failure symptoms like no-start, poor shifting, and false DTCs.
- โ A direct-fit replacement, making installation simple.
- โ No need for additional, expensive dealership programming after installation.
Installation Note
Once you install this programmed module, you may need to perform a simple security relearn procedure, which can typically be done in your driveway in about 30 minutes with just the ignition key. This procedure syncs the new PCM with your vehicle’s existing anti-theft system. We include instructions to make this process easy.
Guaranteed Fitment for Your Vehicle
This module is a direct replacement for part number 19209821 and a host of other service numbers. It is guaranteed to fit the following vehicles equipped with the specified engines and options:
- โ 2006 Buick Rainier: 4.2L (Located on LH side of engine)
- โ 2004-2006 Chevrolet Colorado: (Located on RH firewall)
- โ 2006 Chevrolet Trailblazer & Trailblazer EXT: 4.2L (Located on LH side of engine)
- โ 2004-2006 GMC Canyon: (Located on RH firewall)
- โ 2006 GMC Envoy & Envoy XL: 4.2L (Located on LH side of engine)
- โ 2006 Hummer H3: (Located on RH firewall)
- โ 2006 Isuzu Ascender: 4.2L (Located on LH side of engine)
- โ 2006 Isuzu i-280 & i-350: (Located on RH firewall)
- โ 2006 Saab 9-7x: 6-Cylinder (Identical to part numbers 12569773 or 12597521)
This unit also directly 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, and 19209820. By ordering this module, you are getting the correct, updated part for your vehicle.