2004 Sierra 3500 PCM 89017739 Programmed Engine Control Module

Restore Peak Performance to Your GM Truck or Van

Is your trusty 2004 Sierra 3500, or another GM vehicle, suddenly giving you headaches? If you’re dealing with a persistent check engine light, erratic engine behavior, or a frustrating no-start condition, the problem often points directly to a failing Powertrain Control Module (PCM). As the electronic brain of your vehicle, the PCM is responsible for managing everything from fuel mixture and ignition timing to transmission shifts. When it falters, the entire vehicle suffers. This isn’t just an inconvenience; it can affect fuel economy, emissions, and overall vehicle safety.

This replacement Electronic Control Module (ECM), also known as a PCM, is the definitive solution. We take the guesswork and hassle out of the repair by pre-programming the module specifically for your vehicle using your VIN. This means it arrives at your door with the latest GM software updates already installed, ready for a straightforward installation. You get a reliable, plug-and-play fix without the expensive trip to the dealership for programming.

Is Your GM Vehicle Showing These Telltale Signs?

A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your engine’s computer needs attention:

• ✔ Persistent Check Engine Light (CEL)
• ✔ Diagnostic Trouble Codes (DTCs) such as P0601, P0602, P0606, or other communication errors.
• ✔ Engine stalling, stumbling, or hesitating unexpectedly.
• ✔ A complete no-start condition where the engine cranks but won’t fire.
• ✔ Noticeable decrease in fuel economy.
• ✔ Harsh or erratic automatic transmission shifting.
• ✔ Communication issues with diagnostic scan tools.

A Straightforward Guide to Installation

Replacing the PCM on your GM truck or van is a manageable job for a confident DIYer. For the 2004 Sierra 3500, the module is typically located on the driver’s side, under the battery tray. Always consult a service manual for your specific vehicle’s location.

1. Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
2. Access the Module: Depending on the vehicle, you may need to remove the battery and its tray to gain clear access to the PCM.
3. Disconnect the Harnesses: Carefully unplug the electrical connectors from the old PCM. These connectors have locking tabs that need to be released. Avoid pulling on the wires themselves.
4. Remove the Old PCM: Unbolt the old module from its mounting bracket and remove it from the vehicle.
5. Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely plug in the electrical harnesses. 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. Perform Security Relearn: This is a critical step. Most of these GM vehicles require a security relearn procedure (often called a Passlock or Passkey relearn) to allow the vehicle to start. This procedure typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating this cycle three times. This allows the new PCM to synchronize with your vehicle’s anti-theft system.

Verified Vehicle Compatibility

This module is a direct replacement for part numbers 89017739 and 12586243 and fits a wide range of 2004 GM models. Please verify your vehicle is on the list below. Providing your VIN during checkout is essential to ensure we flash the correct software for your specific application.