Restore Peak Performance to Your GM Truck or SUV
Is your truck suffering from baffling electrical issues, a persistent check engine light, or unpredictable performance? As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing Powertrain Control Module (PCM) can be the hidden culprit behind a host of frustrating problems. This isn’t just a replacement part; it’s the central command center for your engine and transmission. This specific 2003-2007 Sierra 2500 PCM is your direct-fit, reliable solution to get your vehicle running smoothly and efficiently again.
We take the guesswork and expensive dealership trips out of the equation. Before this module ships, we flash it with the latest official GM software updates, precisely matched to your vehicle using the VIN you provide. This means it arrives at your door ready for installation, saving you time, money, and the headache of coordinating a programming appointment. It’s the most effective way to address deep-rooted electronic issues and restore the drivability you depend on.
Case Study: A Tricky Diagnosis
I remember a 2005 Silverado 2500 that came into my bay with a complaint of intermittent stalling at stop lights and harsh, unpredictable shifting. The owner had already replaced the throttle body and a few sensors with no luck. The scanner showed a U0100 (Lost Communication with ECM/PCM) code that would come and go. After verifying the wiring and grounds were solid—a critical first step—we focused on the PCM. Heat soak was causing an internal fault in the module’s processor. We installed a VIN-programmed PCM just like this one, performed the security relearn, and the truck ran perfectly. It’s a classic example of how a failing computer can mimic mechanical problems, making a reliable module the key to the fix.
Is Your Truck Showing These Telltale Signs?
- ✔ Persistent Check Engine Light that won’t clear.
- ✔ Diagnostic Trouble Codes (DTCs) pointing to internal module failure, such as P0601, P0602, or P0606.
- ✔ Unexplained stalling, rough idling, or engine hesitation.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A complete no-start condition where the engine cranks but won’t fire up.
- ✔ Communication errors with scan tools (e.g., U0100).
- ✔ Noticeable decrease in fuel economy.
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
- ✔ Locate the PCM: On most GM trucks and SUVs of this era, the PCM is located in the engine bay on the driver’s side, often under or next to the battery tray in a black plastic holder.
- ✔ Disconnect the Harnesses: Carefully lift the locking levers on the electrical connectors and pull them straight out from the module. There are typically two or three large connectors. Inspect them for any corrosion or damage.
- ✔ Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s usually held in by a couple of 10mm or 13mm bolts.
- ✔ Install the New PCM: Seat the new, pre-programmed module into the bracket and secure it. Reconnect the electrical harnesses, ensuring they click securely into place.
- ✔ Reconnect the Battery: Reattach the negative battery terminal.
- ✔ Perform Security Relearn: You will likely need to perform a simple security relearn procedure. Typically, this 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’s service manual will have the exact steps.
Verified Vehicle Compatibility
This module, part number 12602802, is a direct replacement for service numbers 89017750, 12582605, 12589463, 89017734, and 28042802. It is guaranteed to fit a wide range of GM vehicles. Please verify your specific model, year, and engine options below. For some models, matching the ID number 12602802 on your original part is required for compatibility.
Fits Select Models Of:
- Cadillac Escalade, ESV, EXT (2003-2006)
- Chevrolet Avalanche 1500 (2003-2006)
- Chevrolet Silverado 1500, 2500, 3500 (2003-2007 Classic)
- Chevrolet Suburban 1500, 2500 (2003-2006)
- Chevrolet Tahoe (2003-2006)
- Chevrolet SSR (2003)
- GMC Sierra 1500, 2500, 3500 (2003-2007 Classic)
- GMC Sierra Denali (2003-2007 Classic)
- GMC Yukon, Yukon XL 1500, Yukon XL 2500 (2003-2006)
- Hummer H2 (2003-2007)
- Isuzu Ascender (2003)
- GMC Envoy XL (2003)
- Chevrolet Trailblazer EXT (2003)
Frequently Asked Questions
How do I provide my VIN number?
After completing your purchase, simply reply to your order confirmation email with your 17-digit Vehicle Identification Number (VIN). We cannot program and ship your module without it.
Will I need to do anything after installing this PCM?
Yes. While the main engine and transmission programming is done, you will need to perform a security relearn procedure (also known as the Passlock or Passkey relearn). This syncs the new PCM to your vehicle’s anti-theft system and is required for the engine to start. It’s a simple procedure that takes about 30 minutes and requires no special tools.
Is this a plug-and-play part?
Essentially, yes. Because we program it to your VIN, you avoid a trip to the dealer. The only additional step is the security relearn, which you can easily do yourself. Once that’s complete, you’re ready to drive.
What if my original part number is different?
This module replaces several service numbers, including 89017750, 12582605, and 12589463. As long as your vehicle is on the compatibility list and you provide a valid VIN, this module will function correctly. For certain models, matching the ID 12602802 is necessary.
Do I need to send my old PCM back?
No core charge or return is required for this part, saving you the hassle and cost of shipping your old module back.