Is Your Avalanche Running Rough, Stalling, or Throwing Codes?
If you’re dealing with frustrating engine problems in your 2003-2006 Chevy Avalanche 1500โlike a persistent check engine light, erratic shifting, a no-start condition, or poor fuel economyโa failing Powertrain Control Module (PCM) is often the culprit. As the brain of your truck’s engine and transmission, when the PCM starts to fail, it can cause a cascade of issues that are often misdiagnosed, costing you time and money on parts you don’t need.
From the Shop Floor: A Common Scenario
Just last month, a customer brought in his 2004 Sierra 1500โwhich uses the same PCM as your Avalancheโwith an intermittent no-start and a random P0601 (Internal Control Module Memory Check Sum Error) code. He’d already replaced the battery and alternator. The issue was water intrusion. These PCMs are located under the battery tray, and over time, battery acid leaks or moisture can seep down and corrode the connectors and the module’s internal board. We swapped in a correctly programmed module, and the truck has run flawlessly ever since. This isn’t a rare case; I’ve seen this exact failure on dozens of these GM trucks.
The Direct-Fit, Programmed Solution
This isn’t just a replacement part; it’s a complete solution. We are offering a genuine GM Electronic Control Module (part #12602802) that is professionally programmed to your truck’s specific Vehicle Identification Number (VIN). This critical step ensures that the computer has the correct software and calibrations for your engine, transmission, and factory options. It’s a plug-and-play fix that restores your vehicle’s original performance and reliability.
Key Benefits of This VIN-Programmed PCM:
- โ Fixes Common Issues: Solves problems like check engine lights (for PCM-related codes), harsh shifting, engine stalling, no-start conditions, and communication errors.
- โ VIN-Programmed for Your Truck: We flash the module with the latest GM-certified software using your VIN. This is not a generic, one-size-fits-all part.
- โ No Dealer Visit Required: Once installed, this module is ready to go. You avoid the hassle and high cost of having a dealership program a new module.
- โ Broad Compatibility: This module, also known by service numbers 89017750, 12582605, and 12589463, is a direct replacement for a wide range of GM trucks and SUVs, including the Silverado, Sierra, Tahoe, Yukon, Escalade, and Hummer H2.
Easy Installation for the DIYer
You can get your truck back on the road in under an hour with basic hand tools. Follow these simple steps to install your new 2003-2006 Avalanche 1500 PCM.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Access the PCM: On most of these GM trucks, the PCM is located in the engine bay on the driver’s side, mounted in a black plastic bracket beneath the battery tray. You may need to remove the battery to gain full access.
- Disconnect the Connectors: Carefully unclip and remove the wiring harness connectors from the old PCM. Inspect the connectors for any signs of corrosion or bent pins. Clean them with electrical contact cleaner if necessary.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Seat your new, pre-programmed PCM into the bracket and secure it. Reconnect the wiring harnesses, ensuring they click firmly into place.
- Final Steps: Reinstall the battery and connect the negative terminal. Your vehicle may require a security relearn procedure, which can typically be done by cycling the key and is detailed in many online forums or service manuals for your specific model.
By ordering this part, you’re not just buying a component; you’re getting a reliable fix backed by years of diagnostic experience. Simply provide your VIN at checkout, and we’ll handle the programming to get you a part that works right out of the box. Restore your truck’s proper function and drive with confidence again.