Programmed 2004 Avalanche 2500 PCM 89017739 | Engine Control Module

Restore Your Truck’s Brain and Get Back on the Road

Is your 2004 Avalanche 2500 running rough, throwing confusing check engine lights, or refusing to start intermittently? As a technician with over two decades of experience, I’ve seen these symptoms countless times. Often, the culprit isn’t a bad sensor or a wiring issue—it’s the Powertrain Control Module (PCM), the central computer of your vehicle. When it fails, it can cause a cascade of frustrating and hard-to-diagnose problems. This isn’t just an inconvenience; it’s a reliability issue that can leave you stranded.

This replacement 2004 Avalanche 2500 PCM is the definitive solution to get your truck running like it should. We take the guesswork and hassle out of the repair. Simply provide your vehicle’s VIN during checkout, and our experts will flash the module with the latest, most stable GM factory software specific to your truck. It arrives at your door ready for installation, with no need for an expensive trip to the dealership for programming. This is the same process we use in the shop to ensure a reliable, long-term fix.

Is Your GM Truck Showing These Symptoms?

• ✔ Unexplained Check Engine Light with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
• ✔ Engine cranks but refuses to start (no-start condition).
• ✔ Rough or erratic idling and stalling.
• ✔ Noticeable decrease in fuel economy.
• ✔ Harsh or incorrect transmission shifting.
• ✔ Communication errors with diagnostic scan tools.

A Straightforward Guide to Installation

Replacing the PCM on these GM trucks is a job most DIYers can handle with basic tools. This pre-programmed module makes it even simpler. For the 2004 Avalanche 2500, you’ll find it under the hood on the driver’s side, below the battery tray.

1. Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
2. Access the Module: You may need to remove the battery and the battery tray to gain clear access to the PCM.
3. Disconnect Connectors: Carefully unplug the electrical harness connectors from the old PCM. There are typically release tabs that need to be pressed or lifted. Avoid pulling on the wires themselves.
4. Remove the Old PCM: Unbolt the old module from its mounting bracket.
5. Install the New PCM: Mount your new, pre-programmed 2004 Avalanche 2500 PCM and securely re-attach the electrical connectors. You should hear a click as they lock into place.
6. Reassemble: Reinstall the battery tray and battery, then reconnect the negative battery terminal.
7. Security Relearn: You may need to perform a simple security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes. This allows the new PCM to sync with your vehicle’s anti-theft system.

Verified Vehicle Compatibility

This module, part number 89017739 (also compatible with 12586243), is a direct-fit replacement for a wide range of 2004 and some 2005 GM vehicles. Please verify your specific model and options below:

Frequently Asked Questions