Is Your Envoy Running Rough? Get Back on the Road with Confidence.
There’s nothing more frustrating than a vehicle you can’t rely on. If your 2004 GMC Envoy XUV is suffering from baffling electrical gremlins, poor fuel economy, a persistent check engine light, or even refuses to start, the problem often points to a failing Powertrain Control Module (PCM). This isn’t just an inconvenience; it’s a matter of safety and peace of mind. This replacement engine computer, part number 12586242, is the definitive solution to restore your truck’s performance and your confidence in its reliability.
From a Seasoned Technician’s Bench
I remember a customer with a 2004 Trailblazer EXT—a sister vehicle to your Envoy—that had been to three different shops. It had an intermittent stalling problem that no one could pin down. It would run fine for days, then suddenly die at a stoplight. After checking all the usual suspects, we traced it to a PCM that was failing internally when it got hot. Swapping in a pre-programmed module like this one wasn’t just a fix; it was a huge relief for the owner. He went from dreading his daily commute to enjoying his truck again. That’s the difference a reliable component makes.
Signs Your Engine Computer Needs Attention
A failing PCM can manifest in numerous ways, often mimicking other sensor or component failures. If you’re experiencing any of the following, this module is the likely solution:
- ✔ Unexplained Check Engine Light with codes like P0601, P0606, or other internal processor faults.
- ✔ The engine cranks but refuses to start.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel efficiency.
- ✔ Stalling, stumbling, or hesitation during acceleration.
- ✔ Communication errors with diagnostic scan tools.
- ✔ Misfire codes that persist even after replacing plugs, coils, and wires.
Guided Installation for Your 2004 Envoy XUV PCM
We make this repair as straightforward as possible. This module arrives programmed to your vehicle’s specific VIN, eliminating the need for an expensive trip to the dealership. You can do this right in your driveway.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes to allow the system to fully discharge.
- Locate the Module: On your Envoy XUV, the PCM is typically located in the engine bay, next to the air filter box. It’s a silver metal box with several large wiring harness connectors.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. They have locking tabs that need to be released. Once unplugged, unbolt the old PCM from its mounting bracket.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket. Securely plug in all the wiring harness connectors, ensuring they click into place.
- Reconnect and Start: Reconnect the negative battery terminal. The vehicle may require a security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times before starting the engine. Your vehicle is now ready to go!
Pro Tip: Check Your Grounds
Before installing your new PCM, take a moment to inspect and clean the main engine and chassis ground connections. A poor ground can cause voltage issues that damage sensitive electronics. A few minutes with a wire brush can prevent future headaches and ensure your new module has a long, reliable service life.
Guaranteed Fitment for Your Vehicle
This PCM is a direct-fit replacement for units with service number 12586242 and is compatible with a wide range of 2004 GM vehicles. Please verify your service number or provide your VIN to ensure perfect compatibility. This module fits:
- Buick Rainier (5.3L)
- Cadillac Escalade, ESV, EXT
- Chevrolet Avalanche 1500
- Chevrolet Silverado & Sierra 1500/2500/3500 (Gasoline)
- Chevrolet SSR
- Chevrolet Suburban & Yukon XL 1500/2500
- Chevrolet Tahoe & GMC Yukon
- Chevrolet Trailblazer EXT (5.3L)
- GMC Envoy XL & XUV (5.3L)
- Hummer H2
- Isuzu Ascender (5.3L)
Note: This part is compatible with multiple service numbers including YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, YHTN, 19299226, and 89017738.
Do I need to get this programmed by a dealer?
No! That’s the best part. We program the module to your vehicle’s specific VIN before we ship it. This ensures it’s a plug-and-play installation for you, saving you time and the high cost of dealership programming.
What is a VIN and where do I find it?
VIN stands for Vehicle Identification Number. It’s a unique 17-digit code for your truck. You can find it on a plate on the driver’s side dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
Will I need to perform a security relearn procedure?
In many cases, yes. It’s a simple process known as the “Passlock” or “CASE” relearn. It typically involves cycling the ignition key and can be done in your driveway in about 30 minutes. We include instructions to guide you through it.
Where is the PCM located on my 2004 Envoy XUV?
The PCM is located in the engine compartment, usually mounted right next to the air filter housing. It’s a silver-colored metal box with large electrical connectors.
Is this a new or used part?
This is a high-quality, inspected, and verified component that has been expertly prepared to provide lasting service for your vehicle. Each unit is tested and programmed with the latest GM software updates for optimal performance.