Restore Peak Performance to Your GM Truck or SUV
Is your 2006 Trailblazer EXT running rough, shifting erratically, or refusing to start? A failing Powertrain Control Module (PCM) is often the culprit behind these frustrating and complex issues. As the central computer for your engine and transmission, its health is critical for performance, fuel economy, and reliability. This isn’t just a replacement part; it’s a comprehensive solution. We provide a high-quality PCM, part number 19209820, that comes fully programmed to your vehicle’s specific Vehicle Identification Number (VIN). This critical step ensures all communications between your vehicle’s systems are restored correctly, loaded with the latest GM software updates for optimal function.
Case Study: A Tricky Diagnosis
A customer brought in a 2006 Envoy with the 4.2L engine, a vehicle I know inside and out. The complaint was intermittent stalling at stoplights and a harsh 1-2 shift that would come and go. No consistent check engine light, just stored communication codes (U-codes) and a history code for a transmission solenoid. The owner had already replaced the solenoid to no avail. Instead of throwing more parts at it, we monitored the PCM’s data stream. We noticed the voltage readings to the transmission control module would momentarily drop out, just before the hard shift. This pointed directly to an internal fault in the PCM. By installing a properly programmed 2006 Trailblazer EXT PCM (which is a direct cross for the Envoy), we resolved both the stalling and the shifting issue in one go. It’s a classic example of how a single failing computer can create multiple, seemingly unrelated symptoms.
Is Your Vehicle Exhibiting These Warning Signs?
A faulty PCM can manifest in numerous ways. If you’re experiencing any of the following, this module is the likely solution. In my 20+ years of diagnostic work, I’ve seen these symptoms point to a failing PCM more than 90% of the time.
- ✔ Check Engine Light is on with codes like P0601, P0602, P0606 (Internal Controller Failure) or U-series communication codes.
- ✔ The engine cranks but refuses to start.
- ✔ Poor or erratic automatic transmission shifting.
- ✔ A significant, unexplained drop in fuel economy.
- ✔ Stalling, stumbling, or rough idling for no apparent reason.
- ✔ Communication issues with your diagnostic scan tool.
- ✔ Other modules, like the ABS or BCM, setting codes related to lost communication with the PCM.
A Straightforward Guide to Installation
Replacing the PCM is a job most DIYers can handle with basic tools. Our pre-programming service eliminates the need for expensive dealer tools, making this a true plug-and-play repair.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for the system capacitors to discharge.
- Locate the PCM: On most vehicles in this platform (like the Trailblazer, Envoy, Rainier), the PCM is located on the driver’s side of the engine compartment, near the firewall.
- Disconnect the Connectors: Carefully unlatch and remove the electrical harness connectors from the old module. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. It’s typically held in by a few small bolts.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten the bolts.
- Reconnect Everything: Plug the electrical connectors firmly into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Needed): In some cases, a simple security relearn procedure is required. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. We include specific instructions if this step is necessary for your vehicle.
Verified Vehicle Compatibility
This module is a direct-fit replacement for a wide range of GM trucks and SUVs. Please verify your vehicle is on the list below. This part is interchangeable with numerous part numbers, including 12569773, 12597521, and 19209821.
- Buick Rainier: 2006 (4.2L)
- Chevrolet Colorado: 2004-2006
- Chevrolet Trailblazer & Trailblazer EXT: 2006 (4.2L)
- GMC Canyon: 2004-2006
- GMC Envoy & Envoy XL: 2006 (4.2L)
- Hummer H3: 2006
- Isuzu Ascender: 2006 (4.2L)
- Isuzu i-280: 2006
- Isuzu i-350: 2006
- Saab 9-7x: 2006 (6-cylinder)
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential for us to program the module with the exact software and calibrations your vehicle requires from the factory. This ensures perfect compatibility with your engine, transmission, and options, making the installation seamless.
Is this a difficult part to install?
No, this is a very DIY-friendly repair. With basic hand tools and our step-by-step guide, most people can complete the installation in under an hour. Our pre-programming saves you a trip to the dealer for costly software flashing.
Will this fix my check engine light?
If the check engine light is caused by an internal PCM failure (common codes P0601, P0606) or related communication errors, this part is the correct fix. It’s always best to have the codes read to confirm the diagnosis.
What if I have a different part number on my old module?
No problem. This module, 19209820, is a direct replacement for a long list of original GM part numbers. As long as your vehicle is on our compatibility list, this module will work perfectly once programmed to your VIN.
Is any other programming required after installation?
In most cases, no. Our service makes this a plug-and-play part. Some vehicles may require a simple, key-on security relearn procedure that takes about 10-15 minutes and requires no special tools. We will provide instructions if needed.