Restore Peak Performance to Your GM Vehicle
Is your 2004 GM truck, van, or car suffering from erratic behavior, a persistent Check Engine Light, or a no-start condition? The Powertrain Control Module (PCM), often called the ECM or engine computer, is the electronic brain of your vehicle. It manages everything from fuel injection and spark timing to transmission shifting and emissions control. When it fails, it can cause a cascade of frustrating and difficult-to-diagnose problems. This replacement PCM, service number 12586243, is the definitive solution to get your vehicle back on the road and running like new.
We take the guesswork and hassle out of the replacement process. Unlike a generic module from a parts store or salvage yard, each unit we ship is meticulously programmed to your vehicle’s specific Vehicle Identification Number (VIN). This critical step ensures that the module has the correct software and calibrations for your engine, transmission, and factory options. We flash it with the latest updates available from GM, often resolving issues that were present even when the vehicle was new. This means no expensive trips to the dealership for programming—it arrives ready for installation.
From the Diagnostic Bay
I once had a 2004 GMC Savana 2500 in the shop that was a real head-scratcher. The owner had replaced the throttle body, multiple O2 sensors, and the mass airflow sensor chasing a rough idle and intermittent stalling. The codes were all over the place, pointing to different circuits each time we cleared them. After hours of chasing wires, we finally hooked up a scope to the 5-volt reference circuit coming from the PCM. We found the signal was noisy and dropping out intermittently. The PCM was failing internally, causing all the connected sensors to send bad data. A new, programmed PCM fixed everything in one shot. It’s a powerful reminder that sometimes the problem lies with the conductor of the orchestra, not the individual instruments.
Is Your Vehicle Showing Signs of a Faulty PCM?
A failing engine computer can manifest in numerous ways. If you’re experiencing any of the following symptoms, a faulty PCM could be the culprit. This replacement GM PCM 12586243 is designed to correct these issues and restore proper vehicle function.
- ✔ Persistent Check Engine Light (CEL) with various or inexplicable codes.
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
- ✔ No-start or hard-start conditions, especially when the engine is warm.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to pass state emissions testing.
- ✔ Communication errors with diagnostic scan tools.
The Superior Solution: A VIN-Programmed GM PCM 12586243
Don’t settle for a one-size-fits-all solution. This module is a direct-fit replacement for original part numbers 12586243 and 89017739, and is compatible with a vast range of 2004 GM vehicles, including the Savana, Express, Silverado, Sierra, Corvette, Trailblazer, and many more. The key to our service is the VIN-specific programming. When you provide us with your VIN, you are guaranteed to receive a module that is perfectly matched to your vehicle’s original specifications, ensuring seamless integration and optimal performance. The installation is straightforward for any competent DIY mechanic or professional technician. In most cases, after installation, you will only need to perform a simple security relearn procedure, which can be done without any special tools.
Frequently Asked Questions
Do I need to get this module programmed by a dealer?
No. We handle all the programming before we ship the module to you. Simply provide your vehicle’s VIN at checkout, and it will arrive ready to be installed with the latest GM software updates.
Where can I find my VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, the driver’s side door jamb sticker, or on a small plate on the driver’s side of the dashboard, visible through the windshield.
Is this installation difficult?
For most models, the PCM is easily accessible in the engine bay. The process involves disconnecting the battery, unplugging the electrical connectors, unbolting the old module, and installing the new one. A security relearn procedure (instructions provided) is typically required afterward.
What happens if I provide the wrong VIN?
Providing the correct VIN is absolutely critical. An incorrect VIN will result in the wrong programming, and the module will not function in your vehicle. Please double-check your VIN for accuracy before submitting your order.
Will this part fit my 2004 Savana 1500?
Yes, this module is the correct fit for the 2004 GMC Savana 1500, as well as a wide variety of other GM trucks, vans, and SUVs from that model year. Our programming ensures it works specifically with your vehicle’s configuration.