Restore Peak Performance to Your GM Truck or SUV
Is your truck or SUV suffering from baffling electrical issues, a persistent check engine light, or poor performance? A failing Powertrain Control Module (PCM), the vehicle’s central computer, is often the culprit. I’ve spent two decades under the hood of these vehicles, and I can tell you that a faulty PCM can cause a cascade of problems that seem unrelated, from harsh shifting to a complete no-start condition. This isn’t just a part; it’s the brain of your engine, and getting a reliable replacement is critical. This module, part number 12602802, is your direct-fit, hassle-free solution.
We take the guesswork and extra expense out of the equation. Unlike sourcing a module from a junkyard or a parts store, this PCM arrives at your door fully programmed with the latest GM software updates specifically for your vehicle. Simply provide us with your Vehicle Identification Number (VIN) after purchase, and our experts will flash the module. This ensures it communicates flawlessly with your truck’s other systems right out of the box, restoring the smooth operation and reliability you depend on.
From the Diagnostic Bay: The Intermittent Stall
I remember a 2004 Sierra 2500 that came into my shop with an issue that was driving the owner crazy. It would run perfectly for days, then suddenly stall at a stoplight and refuse to restart for 15 minutes. There were no consistent trouble codes, just a random U0100 (Lost Communication) code stored in the BCM. After checking all the usual suspects—grounds, wiring harnesses, fuel pressure—we focused on the PCM. These modules live in a harsh environment under the hood, and over 15+ years, the constant heat cycles can cause microscopic cracks in the internal circuit board solder joints. When the engine was hot, a connection would fail, killing the engine. Once it cooled, the connection would be restored. Swapping in a properly programmed PCM, like this one, solved the problem for good. It’s a classic failure mode I’ve seen dozens of times.
Is Your GM Vehicle Showing These Symptoms?
- ✔ Check Engine Light is on with communication codes (e.g., P0601, P0606, U0100).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling.
- ✔ Noticeably poor fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to pass an emissions test.
Your Straightforward PCM Installation Guide
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow capacitors to discharge.
- ✔ Locate the PCM: On most of these GM trucks and SUVs, the PCM is located in the engine bay, either on the driver’s side fender well near the airbox or under the battery tray.
- ✔ Disconnect the Harnesses: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Never force them. Inspect the connectors for any corrosion or bent pins.
- ✔ Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s typically held in by a few 10mm or 13mm bolts.
- ✔ Install the New PCM: Mount your new, pre-programmed PCM and securely tighten the bolts. Reconnect the electrical harnesses, ensuring the locking tabs click firmly into place.
- ✔ Reconnect the Battery: Reattach the negative battery terminal. The vehicle may require a security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your owner’s manual for specific instructions.
Verified Fitment for Your GM Truck or SUV
This module is a direct replacement for service numbers 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802. Please verify your part number or contact us with your VIN. It is confirmed to fit the following vehicles:
- Chevrolet Avalanche 1500: 2003, 2004, 2005, 2006
- Chevrolet Silverado 1500/2500/3500: 2003, 2004, 2005, 2006, 2007 (Classic)
- Chevrolet SSR: 2003
- Chevrolet Suburban 1500/2500: 2003, 2004, 2005, 2006
- Chevrolet Tahoe: 2003, 2004, 2005, 2006
- Cadillac Escalade / ESV / EXT: 2003, 2004, 2005, 2006
- GMC Envoy XL: 2003 (5.3L)
- GMC Sierra 1500/2500/3500/Denali: 2003, 2004, 2005, 2006, 2007 (Classic)
- GMC Yukon / XL 1500 / XL 2500: 2003, 2004, 2005, 2006
- Hummer H2: 2003, 2004, 2005, 2006, 2007
- Isuzu Ascender: 2003 (5.3L)
- Chevrolet Trailblazer EXT: 2003 (5.3L)
Frequently Asked Questions
What does ‘VIN Programmed’ mean?
It means we flash the module with your vehicle’s specific VIN and the latest factory software from GM before we ship it. This ensures it works correctly with your engine, transmission, and options, eliminating the need for an expensive trip to the dealership for programming.
Is any additional programming needed after installation?
In most cases, no. Because the unit is pre-programmed to your VIN, it’s a plug-and-play installation. However, some vehicles may require a simple security relearn procedure (often called a ‘key-on’ relearn) which you can do yourself in about 15 minutes. We include instructions if this is necessary for your vehicle.
How do I provide my VIN?
After you complete your purchase, you will receive instructions on how to send us your 17-digit VIN. We cannot ship your part until we receive this information, so please provide it promptly to avoid delays.
Will this fix my transmission shifting problems?
It very well could. The PCM controls both engine functions and transmission shift points. If the module is failing, it can send incorrect signals, leading to harsh shifts, delayed engagement, or getting stuck in one gear. This is a common symptom of PCM failure in these GM trucks.
Where is the part number located on my old PCM?
The part number or service number is printed on a sticker on the case of your original module. You may need to unbolt it to see the sticker clearly. Matching this number is the best way to ensure compatibility.