Restore Peak Performance to Your GM Truck or SUV
If you’re dealing with frustrating issues like a persistent Check Engine Light, erratic engine behavior, poor fuel mileage, or even a no-start condition, a failing Powertrain Control Module (PCM) is often the culprit. I’ve seen it hundreds of times in my bay—these symptoms can make your reliable truck feel unpredictable. This isn’t just an inconvenience; it affects your vehicle’s core performance and safety. This replacement PCM, part number 12602802, is the definitive solution to get your vehicle running smoothly and efficiently again.
What sets this module apart is our professional programming service. Before we ship it, we flash the unit with the latest official GM software updates, tailored specifically to your vehicle’s VIN. This eliminates the need for an expensive trip to the dealership for programming. You get a component that’s ready for installation right out of the box, saving you significant time and money. It’s the most direct path to resolving complex electronic issues and restoring the factory-intended operation of your engine and transmission.
A Technician’s Notebook
I remember a 2005 Sierra 2500 that came in on a tow truck. The owner was frustrated; it would crank but not start, and he’d already replaced the fuel pump and crank sensor. His scanner showed a U0100 ‘Lost Communication with ECM’ code, but it was intermittent. After verifying power and ground at the PCM connectors, we suspected an internal failure. On these GM trucks, the PCM is located under the battery, where it can be exposed to moisture or leaking battery acid over time, causing corrosion and internal shorts. We swapped in a pre-programmed module just like this one, performed the security relearn, and the truck fired up instantly. It’s a classic failure I’ve diagnosed countless times, and a quality, correctly programmed module is the only reliable fix.
Is Your Truck Showing These PCM Failure Signs?
A failing PCM can cause a wide range of problems. If you’re experiencing any of the following, it’s a strong indicator that your module needs attention. Look out for these common symptoms and diagnostic trouble codes (DTCs):
- ✔ Check Engine Light is illuminated with codes like P0601, P0606, or U0100.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Stalling, rough idling, or engine hesitation during acceleration.
- ✔ Communication errors with your scan tool.
DIY Guide: Installing Your New PCM
Replacing the PCM on these GM vehicles is a straightforward job for a confident DIYer. With our pre-programmed module, you can avoid a dealership visit. Follow these steps for a successful installation:
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most of these trucks and SUVs, the PCM is located in the engine bay, on the driver’s side, often under or next to the battery and housed within a black plastic bracket.
- Remove Connectors: Carefully lift the locking tabs on the electrical connectors and gently pull them straight out from the module. Never force them. There are typically two or more large connectors.
- Unbolt the Module: Remove the bolts or clips holding the PCM and its bracket to the vehicle body. The entire assembly should now be free.
- Install the New PCM: Secure the new module in the original location. Reconnect the electrical harnesses, ensuring they click securely into place and the locking tabs are engaged.
- Reconnect the Battery: Attach the negative battery terminal.
- Perform Security Relearn: You will need to perform a simple security relearn procedure so the vehicle recognizes the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. Your vehicle’s service manual will have the exact steps.
Guaranteed Compatibility for Your Vehicle
This module is a direct replacement for service numbers 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802. It is guaranteed to fit the following models:
This PCM fits a wide range of 2003-2007 General Motors trucks and SUVs, including but not limited to:
- ✔ Chevrolet Avalanche 1500 (2003-2006)
- ✔ Chevrolet Silverado 1500, 2500, 3500 (2003-2007 Classic)
- ✔ Chevrolet Suburban 1500, 2500 (2003-2006)
- ✔ Chevrolet Tahoe (2003-2006)
- ✔ GMC Sierra 1500, 2500, 3500 (2003-2007 Classic)
- ✔ GMC Yukon & Yukon XL 1500, 2500 (2003-2006)
- ✔ Cadillac Escalade, ESV, EXT (2003-2006)
- ✔ Hummer H2 (2003-2007)
- ✔ Chevrolet SSR (2003)
- ✔ GMC Envoy XL (2003)
- ✔ Isuzu Ascender (2003)
- ✔ Chevrolet Trailblazer EXT (2003)
Important Note: Please verify your vehicle’s year, make, model, and engine size. For some years, fitment depends on matching the ID number 12602802 from your original part. Providing your VIN is required for us to ensure perfect programming and compatibility.
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to access the latest official GM software specific to your truck’s engine, transmission, and factory options. Programming the 2003-2006 Avalanche 1500 PCM with your VIN ensures it works correctly right out of the box.
Is this a simple plug-and-play installation?
Almost. Because it comes pre-programmed, you will not need a scan tool for software flashing. However, you will need to perform a standard security relearn procedure, which takes about 30 minutes and involves cycling the ignition key. This pairs the new module to your vehicle’s anti-theft system.
Will this fix my specific problem?
This PCM is a direct solution for module-related failures, which cause symptoms like no-start conditions, communication error codes (like P0601), and erratic engine performance. While it solves many common issues, always ensure your vehicle has been properly diagnosed by a qualified mechanic or experienced DIYer first.
What if my original part number is different?
This module, part number 12602802, also replaces several other service numbers, including 89017750, 12582605, and 12589463. As long as your vehicle is on our compatibility list, this part will function as a direct replacement.
Is any other programming required after installation?
In most cases, no. Once the security relearn is complete, the vehicle should start and run correctly. Some vehicles may require a Crankshaft Position Sensor (CASE) relearn for optimal performance, which can be done with many mid-range scan tools, but the vehicle will still be drivable without it.