Is Your GM Truck Running Rough? It Could Be The PCM.
If your 2003-2006 Avalanche, Silverado, Sierra, or other GM truck is suddenly giving you headachesโlike refusing to start, shifting erratically, or displaying a Christmas tree of warning lights on the dashโthe Powertrain Control Module (PCM) is a very likely culprit. As a mechanic with over 20 years of experience, I’ve seen these exact issues hundreds of times. The PCM is the brain of your engine and transmission; when it fails, your vehicle’s performance and reliability go with it.
Don’t let a faulty computer keep you off the road or force you into an expensive dealership visit. This is a direct-fit replacement PCM, delivered to your door fully programmed for your specific vehicle. All we need is your Vehicle Identification Number (VIN) during checkout. We handle the complex programming, so you can handle the simple installation.
Expert Pro Tip: Check Your Connectors!
Before you install your new PCM, take a close look at the wiring harness connectors. On these GM trucks, the PCM is often located under the battery tray, an area prone to moisture and corrosion from battery acid fumes. I’ve seen countless modules replaced when the real issue was just a corroded pin in the connector. Use a small brush and electrical contact cleaner to ensure the terminals are bright and clean. This simple five-minute check can prevent communication errors and ensure a successful repair.
The Simple Solution for a Complex Problem
Replacing a modern vehicle’s computer used to mean towing it to the dealer for expensive diagnostics and programming. We’ve eliminated that step. By programming this module with the latest GM software updates using your VIN, we ensure it communicates perfectly with your truck’s systems right out of the box. This is the most efficient way to restore your vehicle’s factory operation.
Symptoms of a Failing Avalanche 1500 PCM:
- โ Check Engine Light is on with various communication or sensor codes.
- โ Engine cranks but will not start.
- โ Harsh or erratic automatic transmission shifting.
- โ Poor fuel economy and engine performance.
- โ Intermittent stalling or rough idling.
- โ “Service Engine Soon” or other warning messages appearing.
Plug-and-Play Installation: No Dealer Visit Required
You can get your truck back to peak condition right in your own driveway. The installation process is straightforward for anyone with basic tools.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the Old PCM: On most compatible models (like the Avalanche, Silverado, Tahoe), it’s found on the driver’s side of the engine bay, typically under or near the battery tray.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. They have locking tabs that need to be released. Then, unbolt the module from its bracket.
- Install the New PCM: Bolt the new module into place, and securely reconnect the wiring harnesses. Make sure they click into place.
- Reconnect Battery: Re-attach the negative battery terminal.
- Perform Security Relearn: Your vehicle may require a simple security relearn procedure, which can be done without any special tools. It typically involves turning the key to the ‘ON’ position for 10-15 minutes. We include instructions for this process.
This module is a direct replacement for service part numbers 89017750, 12582605, 12589463, 12602802, 89017734, and 28042802. Please verify your part number or use our comprehensive fitment list to confirm compatibility with your exact year, make, and model.