Restore Peak Performance to Your GM Truck or SUV
Is your 2004 Sierra 3500, Silverado, Tahoe, or another compatible GM vehicle suffering from perplexing issues like a persistent check engine light, rough idling, intermittent stalling, or erratic transmission shifting? These are classic signs of a failing Powertrain Control Module (PCM), the central computer that manages your engine and transmission’s performance. A faulty PCM can disrupt everything from fuel delivery and spark timing to shift points, leading to poor performance, decreased fuel economy, and the inability to pass an emissions test. Don’t let a failing computer keep your truck off the road. This replacement PCM, service number 12586242, is the definitive solution to get your vehicle running reliably again.
From the Diagnostic Bay
We had a 2004 Yukon XL come into the shop with a complaint of intermittent stalling at stoplights and a check engine light that had been on for months. The owner had already replaced the MAF sensor and a couple of O2 sensors based on the codes, but the problem persisted. Our lead tech connected his scan tool and noticed that while the sensors were new, the data they were sending was erratic. Instead of chasing ghosts, he checked the 5-volt reference signal from the PCM and found it was fluctuating. This indicated an internal fault in the module itself. We installed a VIN-programmed PCM, performed the security relearn, and the truck ran perfectly. The owner was thrilled to finally have a reliable vehicle again after wasting hundreds on unnecessary parts.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) for various sensor circuits.
- ✔ Engine stalling for no apparent reason, especially when coming to a stop.
- ✔ Rough or unstable engine idle.
- ✔ A noticeable drop in fuel efficiency.
- ✔ Harsh or delayed shifting from the automatic transmission.
- ✔ Complete no-start condition where the engine cranks but won’t fire.
- ✔ Inability for a scan tool to communicate with the module.
The Right Solution: A Pre-Programmed 2004 Sierra 3500 PCM
Replacing the PCM on these vehicles isn’t just a matter of swapping boxes. The module must be programmed with your vehicle’s specific Vehicle Identification Number (VIN) and the latest software updates from General Motors. Our service eliminates the need for an expensive trip to the dealership. When you order from us, we flash the module with your VIN before it ships. This ensures that it communicates correctly with all the other modules in your truck, from the instrument cluster to the anti-lock brake system. This unit is a direct replacement for service number 12586242 and a host of other compatible numbers, including YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, and YHTN, ensuring broad compatibility across the 2004 GM truck and SUV lineup.
Installation is Straightforward
For most trucks like the Sierra and Silverado, the PCM is located on the driver’s side, under the battery tray. After disconnecting the battery, the module can be unbolted and the main wiring harness connectors removed. Once the new module is installed and the battery is reconnected, you may need to perform a simple security relearn procedure, which can typically be done without special tools. This procedure syncs the new PCM with your vehicle’s anti-theft system. We can provide easy-to-follow instructions for this process.
Frequently Asked Questions
Is this PCM truly plug-and-play?
Yes, for the most part. Because we program the module to your specific VIN before shipping, it arrives ready to be installed. The only additional step you may need to perform is a security relearn procedure, which pairs the new computer with your vehicle’s anti-theft system. This can often be done with a simple key-cycling process.
How do I provide my vehicle’s VIN?
After you complete your purchase, you will receive an email with instructions on where to send your VIN. You can also add your VIN in the notes section during checkout. We cannot ship your part until we have this information.
My original part number is different. Will this still work?
Yes. This module, 12586242, is the hardware for many different software calibrations. It is a direct replacement for numerous service numbers, including YFKD, YFXN, YHTN, and others listed in the description. As long as your vehicle—make, model, year, and engine—is on our compatibility list, this module will work perfectly once programmed.
Do I need to send my old PCM back (core charge)?
No, there is no core charge for this particular part. You can keep your old module or recycle it locally.
What if I have issues after installation?
Our team of experts is here to help. If you encounter any issues, such as trouble with the security relearn procedure or persistent fault codes, please contact us. We can provide diagnostic support to ensure your vehicle is running correctly.