Restore Your Truck’s Brain and Get Back on the Road
Is your 2003-2007 GMC Sierra Denali, or another compatible GM truck, giving you headaches? If you’re dealing with a persistent check engine light, erratic engine behavior, stalling, or a no-start condition, the problem often traces back to a failing Powertrain Control Module (PCM). As the central computer of your vehicle, a faulty PCM can cause a host of frustrating and difficult-to-diagnose issues. I’ve seen it countless times in my 20+ years in the shop—a perfectly good engine held back by a failing electronic brain.
This isn’t just a replacement part; it’s a direct solution. We take the guesswork and high dealership costs out of the equation. This genuine GM PCM, service number 12602802, arrives at your door pre-programmed with the latest GM software updates, specifically flashed to your vehicle’s unique VIN. This ensures seamless communication with your truck’s other modules, restoring the performance, fuel efficiency, and reliability you depend on. Stop chasing ghosts in the machine and get the definitive fix for your truck’s electronic woes.
Case Study: A Tricky Diagnosis
A customer brought in his ’05 Silverado 2500 with a 6.0L engine. The complaint was intermittent stalling, but only after it was fully warmed up and driven for 30+ minutes. No codes were stored, making it a real challenge. We checked fuel pressure, sensors, and wiring—everything looked fine. From experience, I know these PCMs can become sensitive to heat over time. We used a heat gun to carefully warm the PCM housing with the engine running, and within minutes, the engine sputtered and died. After cooling, it started right back up. A new, properly programmed PCM like this one solved the problem permanently. The customer was thrilled to have his dependable work truck back.
Is Your GM Truck Showing These Signs?
A failing PCM can manifest in various ways. If you’re experiencing any of the following, this module is the likely solution:
- ✔ Check Engine Light is on with PCM-related Diagnostic Trouble Codes (DTCs) such as P0601, P0602, P0606, or U0100.
- ✔ The engine cranks but will not start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The vehicle stalls unexpectedly, either while driving or at idle.
- ✔ Misfires or rough running conditions that aren’t resolved by new spark plugs or coils.
- ✔ Failure to pass state emissions testing.
A Straightforward Guide to PCM Installation
Installing your new PCM is a manageable job for a DIY enthusiast. By following these steps, you can avoid a costly trip to the shop. Just remember that a Crankshaft Variation Relearn (CASE Relearn) procedure is required after installation using a capable scan tool.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental reconnection.
- Locate the PCM: On most of these GM trucks and SUVs, the PCM is located in the engine bay on the driver’s side, often under or next to the battery tray or near the air filter box.
- Disconnect the Harnesses: Carefully disengage the locking tabs on the electrical connectors. These can be brittle, so apply steady, even pressure. Pull the connectors straight out from the module.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. There are typically a few 7mm or 10mm bolts holding it in place.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and secure the bolts. Reconnect the electrical harnesses, ensuring they click firmly into place.
- Reconnect Power: Reattach the negative battery terminal and tighten it securely.
- Final Step – CASE Relearn: The vehicle will likely start and run, but for optimal performance and to clear any related check engine lights, you must perform a CASE Relearn. This can be done by any professional shop or with a high-level bidirectional scan tool.
Confirmed Vehicle Compatibility List
This module is a direct-fit replacement for a wide range of GM trucks and SUVs. It is compatible with service numbers 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802. Please verify your vehicle is on the list below. If you’re unsure, just send us your VIN!
CADILLAC ESCALADE, ESV, EXT (2003-2006)
HUMMER H2 (2003-2007)
ISUZU ASCENDER (2003)
CHEVROLET SSR (2003)
CHEVROLET/GMC SILVERADO & SIERRA 1500, 2500, 3500 (2003-2007 Classic)
GMC SIERRA DENALI (2003-2007 Classic)
CHEVROLET/GMC SUBURBAN & YUKON XL 1500, 2500 (2003-2006)
CHEVROLET/GMC TAHOE & YUKON (2003-2006)
CHEVROLET TRAILBLAZER EXT (2003)
GMC ENVOY XL (2003)
Note: Fitment can depend on specific options like engine size. For 2007 models, this fits the ‘Classic’ body style only.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential. We use it to load the exact, factory-correct software and calibrations for your specific truck. This ensures the PCM works perfectly with your engine, transmission, and options, eliminating the need for expensive dealership programming.
What is a CASE Relearn and is it required?
A Crankshaft Variation Relearn (CASE Relearn) synchronizes the new PCM with your engine’s crankshaft position sensor. While the truck will usually run without it, completing this procedure with a capable scan tool is required to achieve optimal engine performance, prevent misfire codes, and turn off the check engine light.
Is this a simple plug-and-play installation?
Yes, the physical installation is plug-and-play. Because we program it to your VIN, you can install it yourself and drive to a shop for the final CASE relearn, or have your mechanic perform the entire process. It saves you the step of having the vehicle towed to a dealer for programming.
Will this fix my vehicle’s problem for sure?
This PCM is a direct solution for a failed module. While it resolves the vast majority of issues listed, proper vehicle diagnosis is always recommended. A PCM failure can mimic other issues, such as a bad sensor or wiring fault. This part will definitively fix a faulty PCM.
How do I provide my VIN after purchase?
After you complete your purchase, simply reply to your order confirmation email with your 17-digit VIN, or send it to us through the platform’s messaging system. We cannot ship your module until we receive this information.