Restore Peak Performance to Your GM Vehicle
Is your Silverado, Tahoe, Hummer H2, or other GM truck or SUV suffering from frustrating engine problems? Issues like a persistent check engine light, poor fuel economy, erratic shifting, or even a no-start condition can often be traced back to a failing Powertrain Control Module (PCM). As the central computer for your engine and transmission, a faulty PCM can cause a cascade of problems that are difficult to diagnose. This replacement PCM, part number 12602802, is the definitive solution to get your vehicle running reliably again.
From the Diagnostic Bay
We had a 2005 Sierra 2500 come into the shop with a random misfire and a transmission that shifted hard from first to second. The owner had already replaced the spark plugs, wires, and even the transmission fluid and filter, with no improvement. After hooking up our scanner, we saw no communication with the PCM. A quick check of the powers and grounds to the module confirmed they were good. The internal PCM processors had failed. We installed a VIN-programmed module just like this one, performed a quick CASE relearn, and the truck ran and shifted like it just rolled off the factory floor. It saved the customer from a costly and unnecessary transmission replacement.
Symptoms of a Failing GM PCM
If your vehicle is experiencing any of the following issues, a failing PCM could be the culprit. Replacing it with a correctly programmed unit is essential for a lasting repair.
- ✔ Persistent Check Engine Light (CEL) with communication-related codes (e.g., U0100).
- ✔ Unexplained engine misfires or rough idling.
- ✔ The engine cranks but refuses to start.
- ✔ Harsh, delayed, or erratic automatic transmission shifting.
- ✔ A sudden and significant decrease in fuel mileage.
- ✔ Failure to pass state emissions testing.
- ✔ Intermittent stalling for no apparent reason.
The Critical Advantage of a Programmed GM PCM 12602802
Simply installing a used or unprogrammed module from another vehicle will not work. Modern GM vehicles use the PCM to manage everything from fuel injection and spark timing to transmission shift points and anti-theft systems. Our service eliminates the guesswork and the need for expensive dealership programming. When you order, you provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). We then use that information to flash the module with the latest, most up-to-date GM factory software specific to your exact build. This ensures that the PCM recognizes your engine, transmission, axle ratio, tire size, and all factory-installed options, making for a seamless installation process.
This module is a direct replacement for multiple service numbers, including 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802. It fits a wide range of popular GM trucks and SUVs from 2003 to 2007, such as the Chevrolet Silverado, Suburban, Tahoe, Avalanche; the GMC Sierra and Yukon; the Cadillac Escalade; and the Hummer H2. Please verify the extensive fitment list to confirm compatibility with your specific model and year.
Installation Note
While this PCM comes fully programmed, installation may require a simple security relearn procedure (often called Passlock or Passkey relearn) and a Crankshaft Variation Relearn (CASE relearn). The security relearn can typically be performed by the owner with a specific key-cycling procedure, while the CASE relearn may require a diagnostic scan tool. These steps are necessary to sync the new PCM with your vehicle’s anti-theft system and crankshaft position sensor for optimal performance.
Frequently Asked Questions
Do I need to have this PCM programmed by a dealer?
No. This PCM comes fully programmed to your vehicle’s VIN before it is shipped. We flash it with the latest GM software updates, so it’s ready for installation right out of the box.
What is a CASE relearn and will I need to perform one?
A CASE (Crankshaft Angle Sensor Error) relearn synchronizes the PCM with the crankshaft position sensor. It is often required after PCM replacement to prevent a misfire code. This procedure typically requires a bi-directional scan tool.
Is this part difficult to install?
For most compatible vehicles like the Silverado or Sierra, the PCM is located under the hood on the driver’s side, near the battery. It is a straightforward component to replace with basic hand tools. The most important steps are disconnecting the battery first and ensuring the connectors are seated properly.
How do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit VIN. You can typically find your VIN on the driver’s side of the dashboard (visible through the windshield), on the driver’s door jamb sticker, or on your vehicle’s registration and insurance documents.
What happens if I install this without doing the security relearn?
If a security relearn is required and not performed, the vehicle’s anti-theft system will likely prevent the engine from starting. The engine may crank but will not fire up.