Programmed 2004-2005 LeSabre PCM 12583827 | VIN-Matched with GM Updates

Restore Your Buick’s Performance and Reliability

Is your 2004-2005 Buick LeSabre, or another compatible GM vehicle, giving you headaches? If you’re dealing with a persistent check engine light, unpredictable stalling, rough idling, or poor fuel economy, the culprit is often the very brain of your engine: the Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen firsthand how a failing PCM can create a cascade of frustrating and hard-to-diagnose issues. This isn’t just a part; it’s the central command center for your engine’s performance and efficiency.

We take the guesswork and hassle out of the repair. This replacement PCM, part number 12583827, arrives at your door fully programmed to your specific vehicle. Simply provide us with your Vehicle Identification Number (VIN) after purchase, and we’ll flash the module with the latest official GM software. This ensures perfect communication between the engine, transmission, and other systems, often resolving issues that even the original factory software didn’t address. This is the most effective way to restore your vehicle’s original drivability and pass that emissions test.

Common Signs of a Failing PCM

• ✔ Persistent Check Engine Light (CEL)
• ✔ Diagnostic Trouble Codes (DTCs) related to internal module failure, such as P0601, P0602, P0604, or P0606.
• ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
• ✔ Harsh or erratic automatic transmission shifting.
• ✔ A noticeable drop in fuel mileage.
• ✔ The vehicle fails to start, but the battery and starter are good.
• ✔ Failure to pass state emissions testing.

A Straightforward Guide to Installation

1. ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
2. ✔ Locate the PCM: On most vehicles like the Buick LeSabre, the PCM is located inside the air cleaner filter box assembly in the engine compartment. You will need to open the airbox to access it.
3. ✔ Disconnect and Remove: Carefully unplug the electrical harness connectors from the old module. Press the release tabs firmly. Once disconnected, remove any bolts or clips holding the module in place and lift it out.
4. ✔ Install the New Module: Seat the new, programmed PCM in the same position as the old one and secure it. Reconnect the electrical harnesses, ensuring they click securely into place.
5. ✔ Reconnect Power: Reattach the negative battery terminal.
6. ✔ Perform Security Relearn: Most GM vehicles of this era require a simple security relearn procedure. Turn the key to the ‘ON’ position (without starting) for 10-15 minutes, then turn it ‘OFF’ for 10 seconds. Repeat this cycle three times. The vehicle should then start and run normally.

Verified Vehicle Compatibility

This module is a direct-fit replacement for part numbers 12583827 and 12583826 on a wide range of General Motors vehicles. Please verify your part number or consult the list below. This is a crucial component for restoring your vehicle, and our VIN programming ensures it works for your specific application.