Restore Peak Performance and Drive with Confidence
Is your truck or SUV feeling unpredictable? Experiencing frustrating issues like a persistent check engine light, erratic shifting, or intermittent stalling can steal the joy and confidence from your drive. The Powertrain Control Module (PCM) is the central command center of your vehicle, orchestrating everything from fuel delivery to transmission shifts. When it falters, the entire system suffers. This replacement Engine Control Module, part number 12586242, is the definitive solution to bring back the smooth, reliable performance you depend on. We take the complexity out of the repair by programming it specifically to your vehicle’s VIN before it ships, ensuring a seamless and effective installation.
Signs Your Engine’s Brain Needs Attention
A failing PCM can manifest in confusing ways. If you’re noticing any of the following symptoms, it’s a strong indicator that your module is the culprit. Replacing it can restore your vehicle’s health and your peace of mind.
- ✔ Check Engine Light: Often with communication error codes like P0601, P0602, or P0606.
- ✔ Rough Shifting: Experiencing harsh, delayed, or unpredictable gear changes.
- ✔ Poor Fuel Economy: A sudden and unexplained drop in your MPG.
- ✔ Engine Stalling: The engine cuts out unexpectedly, especially when coming to a stop.
- ✔ No-Start Condition: The engine cranks but refuses to start, even with a good battery and starter.
- ✔ Erratic Instrument Cluster: Gauges behaving strangely or warning lights flashing without reason.
An Expert’s Note: The Case of the Stalling Sierra
I once worked on a 2004 Sierra 1500 that had its owner completely stumped. It would stall randomly at red lights—a nerve-wracking and dangerous problem. He had replaced sensors and checked wiring for weeks. After plugging in my scanner, I saw the tell-tale signs of an internal PCM fault. We installed a VIN-programmed module just like this one. The change was immediate. The engine idled perfectly, and the stalling vanished. The owner’s relief was palpable; he could finally trust his truck again for his daily commute and family trips. That’s the power of a solid, correctly programmed module.
Effortless Installation for a Confident Fix
We’ve designed this to be as straightforward as possible. With the programming already handled, you’re just a few simple steps away from getting back on the road. While the exact location can vary, this guide covers the most common placement.
- Safety First: Begin by disconnecting the negative terminal on your vehicle’s battery to prevent any electrical shorts.
- Locate the Module: On most trucks and SUVs like the Yukon, Sierra, and Silverado, the PCM is found in the engine bay, on the driver’s side, often under or next to the battery tray. On models like the Trailblazer and Envoy, it’s typically next to the air filter box.
- Disconnect and Remove: Carefully unclip the wiring harness connectors. They have locking tabs that need to be released. Once disconnected, unbolt the module from its mounting bracket and remove it.
- Install the New PCM: Place your new, pre-programmed module into the mounting bracket and secure it. Reconnect the wiring harnesses, ensuring they click firmly into place.
- Reconnect Power: Reattach the negative battery terminal and tighten it securely.
- Perform Security Relearn: Your vehicle’s anti-theft system may need to be synchronized with the new PCM. This is a simple procedure: turn the key to the ‘ON’ position for 10-12 minutes, then ‘OFF’ for 30 seconds. Repeat this cycle 3 times, and the vehicle should then start.
Guaranteed Fit for Your 2004 GM Vehicle
This module is a direct replacement for service number 12586242 and is compatible with a wide range of popular 2004 GM models. Please verify your service number to ensure a perfect match. This part is engineered to fit:
- Buick Rainier (5.3L)
- Cadillac Escalade, Escalade ESV, Escalade EXT
- Chevrolet Avalanche 1500, Silverado 1500/2500/3500, SSR, Suburban 1500/2500, Tahoe, Trailblazer EXT (5.3L)
- GMC Envoy XL/XUV (5.3L), Sierra 1500/2500/3500, Sierra Denali, Yukon, Yukon XL 1500/2500
- Hummer H2
- Isuzu Ascender (5.3L)
Note: This is a direct fit for vehicles with service numbers 12586242, 19299226, 89017738, YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, or YHTN.
Frequently Asked Questions
Do I need to do any programming myself?
No. We handle all the programming for you before shipment. Simply provide us with your vehicle’s 17-digit VIN at checkout, and we will flash the module with the latest GM-certified software for your specific vehicle configuration. It arrives ready to install.
What is the security relearn procedure?
It’s a simple process to sync the new PCM with your vehicle’s anti-theft system. After installation, turn the key to the ‘ON’ position (without starting the engine) for about 10-12 minutes, until the ‘Security’ light on the dash turns off. Turn the key off for 30 seconds. Repeat this two more times for a total of three cycles. On the fourth try, the vehicle should start right up.
Where is the PCM located on my 2004 Yukon?
On the 2004 GMC Yukon, as well as most full-size GM trucks and SUVs from this era (Silverado, Tahoe, Sierra), the PCM is located in the engine compartment on the driver’s side, typically mounted to a bracket underneath the battery tray.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both engine and transmission functions. If the module itself is faulty, it can cause harsh or erratic shifting. This pre-programmed 2004 Yukon PCM will resolve any shifting issues that are directly caused by a failing computer.
What information do you need from me?
All we need is your vehicle’s 17-digit Vehicle Identification Number (VIN). You can find this on your driver’s side door jamb sticker, on your vehicle’s registration, or on the dashboard plate visible through the windshield.