Is Your Cadillac Experiencing Critical Engine Problems?
If your 2004 Cadillac Seville, DeVille, or Pontiac Bonneville is suffering from perplexing issues like intermittent stalling, erratic transmission shifting, a persistent check engine light, or even a complete no-start condition, the root cause is often a failing Powertrain Control Module (PCM). The PCM is the central brain of your vehicle, orchestrating everything from fuel injection and ignition timing to transmission shift points. When it fails, it can create a cascade of problems that are difficult to diagnose and frustrating to live with.
From the Diagnostic Bay
We once had a 2004 Cadillac DeVille come in with a ghost-in-the-machine problem. It would randomly refuse to shift out of second gear, but only after it had been driven for over 30 minutes. All the transmission sensors and solenoids tested fine. After hours of chasing wires, we hooked up a scope to the PCM’s output signals. We discovered that as the module heated up, the signal to the shift solenoid would degrade. The culprit was an internal failure within the original PCM. Replacing it with a correctly programmed unit like this one, part number 12587465, resolved the issue instantly. It’s a classic example of how a faulty PCM can mimic a major transmission failure.
Symptoms of a Failing Powertrain Control Module
- ✔ Unexplained Check Engine Light (CEL) illumination, often with communication error codes (U-codes).
- ✔ Engine performance issues such as rough idling, stalling, or misfiring.
- ✔ A noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The vehicle cranks but refuses to start.
- ✔ Inability for diagnostic scan tools to communicate with the module.
- ✔ Other warning lights on the instrument cluster may illuminate without reason.
The Direct Solution: A VIN-Programmed 2004 Seville PCM
Don’t let a faulty computer keep your luxury vehicle off the road. This is a genuine, used GM Powertrain Control Module, part number 12587465, salvaged from a donor vehicle and ready for a new life in yours. The critical advantage of our service is that we professionally flash the module with the latest official GM software updates specifically for your vehicle’s Vehicle Identification Number (VIN). This means the module arrives at your door ready for installation, eliminating the need for expensive programming services at a dealership. It’s a plug-and-play solution designed to get you back on the road quickly and affordably.
Guaranteed Compatibility
This Electronic Control Module is a direct replacement for vehicles equipped with service numbers 12587465, 12586547, or 15576920. It is confirmed to fit the following makes and models:
- 2004 Cadillac Seville (Electronic Control Module; LH engine compartment)
- 2004 Cadillac DeVille (Electronic Control Module; LH engine compartment)
- 2005 Cadillac DeVille (Electronic Control Module; LH engine compartment, ID 12587465)
- 2004-2005 Pontiac Bonneville (Electronic Control Module; LH engine compartment, 4.6L)
Upon purchase, simply provide us with your vehicle’s 17-digit VIN, and our technicians will handle the rest, ensuring the module you receive is a perfect match for your vehicle’s original configuration and features.
Frequently Asked Questions
What exactly is a PCM?
The Powertrain Control Module (PCM) is your vehicle’s main computer. It controls all aspects of the engine and transmission to ensure optimal performance, fuel efficiency, and emissions. It’s a critical component for modern vehicle operation.
How do I provide my VIN?
After you complete your purchase, you can send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot ship your part until we receive this information, as the programming is specific to your car.
Will I need to do anything after installation?
In most cases, you will need to perform a simple security relearn procedure, also known as a VATS relearn. This can typically be done without special tools and involves a sequence of key turns. Instructions are widely available online or in service manuals. This syncs the new PCM with your vehicle’s anti-theft system.
Is this a new part?
No, this is a quality used part that has been carefully sourced from a salvaged vehicle. It has been tested and is fully functional. We then program it with the latest software for your specific VIN, ensuring it performs correctly.
What if my original part number is slightly different?
This module is a direct replacement for several service numbers, including 12586547 and 15576920. As long as your vehicle is listed in our compatibility chart, this module, once programmed to your VIN, will function correctly as a replacement.