Is Your Trailblazer Running Rough? Restore Its Heartbeat.
There’s nothing more frustrating than a vehicle you can’t rely on. If your 2006 Trailblazer is suffering from erratic behavior—stalling at stoplights, hesitating on acceleration, or flashing a persistent Check Engine Light—the problem often points to a failing Powertrain Control Module (PCM). This isn’t just an inconvenience; it’s a core issue that affects performance, fuel economy, and your confidence on the road. This replacement PCM, part number 19209820, is the definitive, hassle-free solution to bring your truck back to life.
We take the guesswork out of the repair. Before this unit ever ships, it is professionally programmed by our technicians with the latest GM software updates, specifically tailored to your vehicle’s unique Vehicle Identification Number (VIN). This means it arrives at your door ready for a straightforward installation, eliminating the need for an expensive trip to the dealership for programming. Regain that smooth, predictable performance and the peace of mind that comes with a reliable ride.
An Expert’s Note: The Case of the Hesitant H3
I once worked on a 2006 Hummer H3 with symptoms that had stumped two other shops. The owner was fed up with random stalling and a transmission that shifted harshly. After checking all the usual suspects, my diagnostics pointed to an internal PCM failure. The owner was worried about a complex, multi-day repair. We supplied a pre-programmed module just like this one. In under an hour, the H3 was running like it just left the showroom. He was amazed at how simple the fix was, restoring not just his vehicle, but his faith in it. That’s the power of getting the right part, programmed correctly from the start.
Warning Signs and How to Overcome Them
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, this module is your solution:
- ✔ Persistent Check Engine Light with codes like P0601, P0606, or other internal processor faults.
- ✔ Unexplained stalling or engine cutting out while driving.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Engine misfires or rough idling even after replacing plugs and coils.
- ✔ No communication with the PCM when using a scan tool.
Guided Installation to Restore Peace of Mind
Installing your new 2006 Trailblazer PCM is a manageable task for a confident DIYer. Follow these steps for a successful replacement.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental power surges.
- Locate the Old PCM: On most Trailblazers and related platforms, the PCM is located in the engine bay, typically on the driver’s side near the firewall or inner fender.
- Disconnect Wiring Harnesses: Carefully release the locking tabs on the electrical connectors and gently pull them straight out from the module. Never force them. Inspect the connectors for any corrosion or damaged pins.
- Remove the Module: Unbolt the old PCM from its mounting bracket. It’s usually held in place by a few small bolts.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and secure it with the bolts. Reconnect the wiring harnesses, ensuring they click securely into place.
- Reconnect the Battery: Reattach the negative battery terminal and tighten it.
- Perform Security Relearn: Your vehicle’s anti-theft system may need to relearn the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. Your vehicle should then start normally.
Tailored Fit for Your Ride
This module is a direct-fit replacement, ensuring compatibility with a range of vehicles. Our programming process makes this the correct 2006 Trailblazer PCM for your specific application. Please verify your vehicle is on the list below:
- CHEVROLET COLORADO 2004-2006 (Electronic Control Module; RH firewall)
- CHEVROLET TRAILBLAZER 2006 (Electronic Control Module; LH engine, 4.2L)
- CHEVROLET TRAILBLAZER EXT 2006 (Electronic Control Module; LH engine, 4.2L)
- GMC CANYON 2004-2006 (Electronic Control Module; RH firewall)
- GMC ENVOY 2006 (Electronic Control Module; 4.2L, LH engine)
- GMC ENVOY XL 2006 (Electronic Control Module; LH engine, 4.2L)
- BUICK RAINIER 2006 (Electronic Control Module; LH engine, 4.2L)
- HUMMER H3 2006 (Electronic Control Module; RH firewall)
- ISUZU ASCENDER 2006 (Electronic Control Module; 4.2L, LH engine)
- ISUZU I-280 2006 (Electronic Control Module; RH firewall)
- ISUZU I-350 2006 (Electronic Control Module; RH firewall)
- SAAB 9-7X 2006 (Electronic Control Module; LH engine, 6 cylinder)
This unit replaces 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.
Frequently Asked Questions
Do I need to provide my VIN?
Yes, providing your Vehicle Identification Number (VIN) is essential. We use your VIN to load the exact, correct software and calibrations for your vehicle’s specific options, ensuring perfect compatibility and performance right out of the box.
Is any additional programming required after installation?
No. This module is delivered fully programmed and ready for installation. The only procedure you may need to perform is the security relearn (also known as the anti-theft relearn), which is a simple process you can do yourself with just the ignition key.
What is the security relearn procedure?
The standard GM relearn procedure involves cycling the ignition. Turn the key to the ‘ON’ position (without starting the engine) and leave it for 10-15 minutes, or until the security light stops flashing. Turn the key ‘OFF’ for 10 seconds. Repeat this process two more times for a total of three cycles. The vehicle should then start and run normally.
Will this fix my specific problem?
This PCM is designed to resolve issues directly caused by a faulty engine computer, such as internal processor errors (e.g., P0601), communication failures, and erratic engine or transmission behavior linked to the module. While it solves many common problems, it’s always best to have a proper diagnosis to confirm the PCM is the source of the issue.
Is this the right part for my vehicle?
This module fits a wide range of 2004-2006 GM trucks and SUVs. Please check the detailed fitment list provided above. As long as your vehicle is on the list, our VIN-based programming will ensure this 2006 Trailblazer PCM is the perfect match for your needs.