Restore Your Truck’s Brain and Get Back on the Road
Is your 2004 GM truck or SUV giving you headaches? Unexplained stalling, a persistent Check Engine Light, or rough, unpredictable performance can be incredibly frustrating. After 20 years in the business, I’ve seen it all, and these symptoms often point directly to a failing Powertrain Control Module (PCM). This isn’t just another part; it’s the central computer of your vehicle, responsible for managing everything from fuel mixture and spark timing to transmission shifting. When it falters, the whole system suffers.
This isn’t a generic, one-size-fits-all solution. This is a direct-fit replacement for part number 89017739 (also compatible with 12586243), and we take the critical step of programming it specifically to your vehicle’s VIN before it ever leaves our facility. This means it arrives loaded with the latest GM factory software updates, tailored to your exact make, model, and options. You get a component that’s ready to install right out of the box, restoring the performance and reliability you depend on without a costly trip to the dealership for programming.
Case Study: A Tricky Diagnosis
A customer brought in their ’04 Yukon XL 2500 with the 8.1L, a close cousin to the Suburban. The complaint was intermittent stalling at stoplights and a random P0606 (PCM Processor Fault) code that would come and go. We checked all the usual suspects—grounds, battery voltage, sensor inputs—and everything looked perfect. The problem was, the issue was so intermittent we couldn’t reliably reproduce it in the bay. Based on my experience with these GMT800 platforms, I suspected the PCM’s internal processor was failing under specific heat and load conditions. We swapped in a VIN-programmed 2004 Suburban 2500 PCM, and the problem vanished instantly. The customer called a week later to say the truck had never run better. It’s a perfect example of how a failing module can create ghost-like issues that are impossible to pin down without replacing the core component.
Is Your GM Truck Showing These Symptoms?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, this module is the likely solution your vehicle needs. In my shop, these are the classic signs I look for when diagnosing a bad engine computer.
- ✔ Vehicle has trouble starting or won’t start at all.
- ✔ Check Engine Light is on with codes like P0601, P0602, P0606, or U0100.
- ✔ Rough or unstable idle.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Engine stalling or hesitating during acceleration.
- ✔ Failure to pass an emissions test.
A Straightforward Guide to Installation
Installing your new 2004 Suburban 2500 PCM is a manageable job for a confident DIYer. The key is taking your time and following the correct procedure. No specialized programming tools are needed since we handle that for you.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes to allow the system to fully discharge.
- Locate the PCM: On most trucks like the Suburban, Silverado, and Sierra, the PCM is located on the driver’s side of the engine bay, under or near the battery tray. On vans like the Express and Savana, it’s typically in the rear of the engine compartment. Check your specific model’s location.
- Disconnect the Connectors: Carefully unlatch and remove the electrical wiring harnesses from the old module. These connectors have locking tabs; do not force them. Inspect the connectors for any corrosion or damage.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. It’s usually held in by a few bolts.
- Install the New Module: Mount your new, pre-programmed PCM securely onto the bracket.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Necessary): In many cases, you will need to perform a security relearn procedure to sync the new PCM with your vehicle’s anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. Consult your owner’s manual for the specific procedure for your vehicle.
Will This Fit My Vehicle?
We guarantee compatibility for the following 2004 models. This module is a direct replacement for parts 89017739 and 12586243. Please verify your vehicle and options from the list below.
ASTRO 04 (LH front by battery)
BLAZER S10/JIMMY S15 04 (RH front engine compartment)
CORVETTE 04 (RH engine compartment), ID 12586243
CTS 04-05 V-Series (RH engine compartment), ID 12586243
ENVOY XL 04 5.3L (next to air box)
ENVOY XUV 04 5.3L (next to air box)
EXPRESS/SAVANA VANS 1500/2500/3500 04 (LH rear engine compartment)
GTO 04 Main (LH engine)
RAINIER 04 5.3L (next to air box)
S10/S15/SONOMA 04 (RH front engine compartment)
SAFARI (GMC) 04 (LH front by battery)
SIERRA/SILVERADO 1500 04 4.3L (LH front under battery)
SIERRA/SILVERADO 2500/3500 04 8.1L Gasoline (LH front under battery)
SSR 04 (next to air box)
SUBURBAN 2500 04 8.1L (LH front under battery)
TRAILBLAZER EXT 04 5.3L (next to air box)
YUKON XL 2500 04 8.1L (LH front under battery)
Frequently Asked Questions
What is VIN programming and why is it important?
VIN programming is the process of loading your vehicle’s specific Vehicle Identification Number (VIN) and its corresponding factory software into the PCM. This is crucial because it ensures the module communicates correctly with your engine, transmission, and other systems. Without it, your vehicle may not start or run properly. We do this for you so it’s ready for installation.
Do I need to do anything after installation?
After installing the module and reconnecting the battery, you will likely need to perform a security relearn procedure, also known as a Passlock or VATS relearn. This simple procedure syncs the new PCM to your vehicle’s anti-theft system and typically takes about 30 minutes using only your ignition key.
Where do I provide my VIN?
After you complete your purchase, you will need to send us your 17-digit VIN. You can typically add it as a note during checkout or send it to us in a message referencing your order number. We cannot ship the module until we receive your VIN.
Is this a plug-and-play part?
Yes, because we program the module to your VIN before shipping, it is a plug-and-play solution. The only additional step required is the security relearn, which does not require any special scan tools.
Will this fix my check engine light?
If your check engine light is caused by an internal PCM failure (like codes P0601, P0606, etc.), then yes, this module will resolve the issue. However, if the light is on due to a faulty sensor or other component, that separate issue will still need to be addressed.