Restore Your Vehicle’s Brain and Bring Performance Back to Life
Is your 2004 Chevrolet SSR or another compatible GM vehicle running rough, stalling unexpectedly, or refusing to start? A faulty Powertrain Control Module (PCM) is often the culprit. As the central computer, it manages everything from fuel mixture and ignition timing to transmission shifts. When it fails, the symptoms can be frustrating and widespread. I’ve spent over two decades in the garage, and I’ve seen firsthand how a failing PCM can mimic a dozen other problems, leading to costly and incorrect repairs. This replacement 2004 SSR PCM is the direct, reliable solution to get your vehicle running properly again.
This isn’t just a part in a box. We take the hassle out of the repair by pre-programming this module to your vehicle’s specific Vehicle Identification Number (VIN). This means it arrives at your door with the latest GM software updates, ready for installation. You get to skip the expensive trip to the dealership for programming, saving you time and hundreds of dollars. It’s the perfect solution for both seasoned mechanics and dedicated DIYers who want a dependable fix.
A Technician’s Notebook: The Intermittent No-Start Nightmare
I remember a 2004 Trailblazer with the 5.3L V8—a vehicle that shares this exact PCM—that came into my shop with a maddening intermittent no-start condition. The owner had already replaced the battery, starter, and fuel pump. It would start fine for a week, then leave him stranded. No consistent codes were stored, just a few random communication errors (U-codes) that would clear. After checking all the wiring and grounds, we focused on the PCM. On the bench, a thermal test revealed the issue: once the module reached operating temperature, internal circuits would fail. A replacement, pre-programmed PCM like this one solved the problem instantly. It’s a classic example of how the PCM can be the hidden cause of the most elusive electrical gremlins.
Is Your GM Vehicle Showing These Red Flags?
A failing engine computer can manifest in numerous ways. If you’re experiencing any of the following, a faulty PCM could be the root cause:
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- ✔ Vehicle refuses to start or has a hard starting condition.
- ✔ Engine stalls for no apparent reason, either while driving or at idle.
- ✔ Noticeable drop in fuel economy.
- ✔ Rough or erratic engine idling.
- ✔ Transmission shifting problems or harsh engagement.
- ✔ Loss of communication with the diagnostic scan tool.
A Straightforward Guide to Your PCM Swap
Replacing the PCM is a manageable job for most DIYers. While the exact location varies by model, the process is generally similar. Always consult a repair manual for your specific vehicle.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the Module: On the 2004 SSR, the PCM is typically found next to the air filter box in the engine compartment. For trucks like the Silverado or Sierra, it’s often under the battery tray on the driver’s side.
- Disconnect the Harnesses: Carefully unplug the electrical connectors from the old PCM. These usually have locking tabs that need to be released. Avoid pulling on the wires themselves.
- Remove the Old Unit: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Secure your new, pre-programmed PCM onto the mounting bracket. Reconnect the electrical harnesses, ensuring they click securely into place.
- Final Steps: Reconnect the negative battery terminal. In many cases, you may need to perform a security relearn procedure (often called a Passlock or Passkey relearn) to allow the vehicle to start. This procedure can typically be done without special tools and instructions are widely available online.
Verified Vehicle Compatibility List
This module, part number 89017739 (also compatible with 12586243), is a direct fit for a wide range of 2004-2005 GM vehicles. Please match your vehicle, engine, and any specific ID codes mentioned below to ensure proper fitment.
- ✔ 2004 Astro / Safari (GMC): (LH front by battery)
- ✔ 2004 Avalanche 2500: (LH front under battery)
- ✔ 2004 Blazer S10 / Jimmy S15: (RH front engine compartment)
- ✔ 2004-2005 CTS: V-Series (RH engine compartment, ID 12586243)
- ✔ 2004 Corvette: (RH engine compartment, ID 12586243)
- ✔ 2004 Envoy XL / XUV, Trailblazer EXT, Rainier 5.3L: (Next to air box, check ID: YFKB, YFKY, YFPZ, YFYY, YHRA)
- ✔ 2004 Express / Savana Van (1500, 2500, 3500): (LH rear engine compartment)
- ✔ 2004 GTO: Main (LH engine)
- ✔ 2004 S10 / S15 / Sonoma: (RH front engine compartment)
- ✔ 2004 Sierra / Silverado 1500 4.3L: (LH front under battery)
- ✔ 2004 Sierra / Silverado 2500 / 3500 8.1L Gas: (LH front under battery)
- ✔ 2004 SSR: (Next to air box, check ID: YFKB, YFKY, YFPZ, YFYY, YHRA)
- ✔ 2004 Suburban 2500 / Yukon XL 2500 8.1L: (LH front under battery)
Frequently Asked Questions About This 2004 SSR PCM
Do I need to do any programming myself?
No. We handle all the programming for you before shipment. Just provide your vehicle’s 17-digit VIN during checkout, and we will flash the module with the latest GM software updates specific to your vehicle. It arrives ready to install.
Where do I find my VIN?
Your VIN can be found on your vehicle’s registration, insurance card, or on the driver’s side of the dashboard, visible through the windshield.
What is a security relearn procedure?
This is a simple procedure that syncs the new PCM with your vehicle’s anti-theft system. It usually involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating a few times. It does not require any special tools. Instructions are easy to find for your specific model.
Is this compatible with part number 12586243?
Yes, this module is a direct replacement for original GM part numbers 89017739 and 12586243, covering a wide range of applications.