Restore Your Truck’s Core Performance and Reliability
Is your 2003-2007 Sierra Denali or other compatible GM truck suffering from frustrating, hard-to-diagnose issues? A failing Powertrain Control Module (PCM) is often the culprit behind problems like erratic idling, poor fuel economy, harsh shifting, or a persistent Check Engine Light. As the central computer of your vehicle, a fully functional PCM is critical for managing everything from fuel delivery and spark timing to transmission operation. This isn’t just a replacement part; it’s a direct solution to restore your vehicle’s drivability and your peace of mind.
We take the guesswork and hassle out of the repair. Each PCM is professionally programmed with the latest GM software updates specifically for your vehicle. Simply provide us with your VIN during checkout, and we handle the complex programming. When your module arrives, it’s ready for installation, saving you a costly trip to the dealership and hours of diagnostic headaches. This is the straightforward, reliable fix you’ve been looking for.
Case Study: A Tricky Diagnosis
A customer brought in a 2006 Silverado 2500 with the 6.0L engine that had an intermittent no-start condition and would occasionally stall at stoplights. They had already replaced the battery, alternator, and crankshaft position sensor with no success. After hooking up my scanner, I noticed communication with the PCM would drop out right before the stall. There were no hard codes, just a history U0100 (Lost Communication With ECM/PCM). In my shop, I’ve seen this exact scenario dozens of times. Internal circuit board failure in these PCMs can cause heat-related issues that don’t always throw a specific component code. We installed one of our pre-programmed PCMs, performed a security relearn, and the truck has run flawlessly ever since. It’s often the brain, not the muscle, that’s the issue.
Is Your Truck Showing These PCM Failure Signs?
A faulty PCM can manifest in various ways. If you’re experiencing any of the following, it might be time for a replacement:
- ✔ Check Engine Light is on with codes like P0601, P0606, or U0100
- ✔ Engine stalling or shutting off while driving
- ✔ Unexplained drop in fuel mileage
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Engine cranks but refuses to start
- ✔ Failure to pass an emissions/smog test
- ✔ Communication errors with diagnostic scan tools
A Straightforward Guide to Your PCM Installation
Replacing the PCM on most of these GM trucks is a job many DIYers can handle. Follow these general steps to get your vehicle back on the road. Always consult a repair manual for your specific model.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental reconnection.
- Locate the PCM: On most compatible trucks and SUVs like the 2003-2007 Sierra Denali, the PCM is located in the engine bay on the driver’s side, often under or next to the battery tray inside a black plastic housing.
- Remove Connectors: Carefully unclip and remove the plastic cover. Then, disengage the locking levers on the electrical connectors and gently pull them straight out from the module. Never force them.
- Unbolt the Module: Remove the bolts or nuts holding the PCM bracket in place. The entire unit should now be free to remove from the vehicle.
- Install the New PCM: Seat the new, pre-programmed PCM into the mounting bracket and secure it. Reconnect the electrical harnesses, ensuring they click securely into place and the locking levers are fully engaged.
- Reconnect Battery: Re-attach the negative battery terminal.
- Perform Security Relearn: You will need to perform a security relearn procedure (often called a Passlock or VATS relearn) to sync the new PCM with your vehicle’s anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating the cycle two more times. Your engine should then start and run.
Verified Vehicle Compatibility
This module is a direct replacement for service numbers 89017750, 12582605, 12589463, 12602802, and 89017734. It fits a wide range of GM vehicles, including:
- Cadillac Escalade, ESV, EXT: 2003-2006
- Chevrolet Avalanche 1500: 2003-2006
- Chevrolet Silverado 1500, 2500, 3500: 2003-2007 (Classic Style)
- Chevrolet SSR: 2003
- Chevrolet Suburban 1500, 2500: 2003-2006
- Chevrolet Tahoe: 2003-2006
- Chevrolet Trailblazer EXT: 2003
- GMC Envoy XL: 2003
- GMC Sierra 1500, 2500, 3500: 2003-2007 (Classic Style)
- GMC Sierra Denali: 2003-2007 (Classic Style)
- GMC Yukon, Yukon XL 1500, Yukon XL 2500: 2003-2006
- Hummer H2: 2003-2007
- Isuzu Ascender: 2003
Please verify your vehicle’s specific options in the detailed fitment list or contact us with your VIN to confirm compatibility.
Do I need to get this PCM programmed?
Do I need to get this PCM programmed?
No. This PCM comes fully programmed to your vehicle’s specific VIN with the latest GM software updates. Just provide your VIN at checkout, and it will arrive ready for installation and a security relearn procedure.
What is a security relearn or CASE relearn?
A security relearn syncs the new PCM with your vehicle’s anti-theft system so the engine will start. It’s a simple procedure you can do yourself. A CASE (Crankshaft Angle Sensor Error) relearn may sometimes be needed to clear a specific code after installation and requires a capable bi-directional scan tool, though it is not always necessary for the vehicle to run properly.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit Vehicle Identification Number (VIN). You can typically add it as a note during checkout or send it to us via a message. We cannot program and ship the module without it.
Will this fix my specific problem?
This PCM is a direct solution for failures within the module itself. While it corrects a wide range of common symptoms, it’s essential to ensure your vehicle’s issues are not caused by other faulty components like sensors or wiring. This part is designed to fix issues directly related to a failing 2003-2007 Sierra Denali PCM.