Restore Peak Performance to Your 2004 GM Truck or SUV
Is your 2004 Chevrolet SSR, GMC Sierra, or Cadillac Escalade suffering from frustrating issues like a persistent check engine light, erratic engine behavior, or a no-start condition? These are common indicators of a failing Powertrain Control Module (PCM), the central computer responsible for managing your vehicle’s engine and transmission. This replacement PCM, part number 12586242, is the definitive solution to restore your vehicle’s reliability and performance. It arrives at your door pre-programmed with the latest official GM software, specifically calibrated to your vehicle’s unique Vehicle Identification Number (VIN).
From the Diagnostic Bay
We had a 2004 Silverado 1500 in the shop that was driving the owner crazy. It would randomly stall at stoplights, but never consistently enough to easily diagnose. There were no hard fault codes, just a history of communication errors. After checking all the usual suspects—fuel pressure, wiring harnesses, grounds—we focused on the PCM. We swapped in a known-good unit, and the problem vanished. The original PCM had an internal intermittent failure that only showed up under specific operating temperatures. Replacing the module with a correctly programmed unit like this one was the only way to provide a permanent fix and give the owner peace of mind.
Is Your Vehicle Exhibiting These Symptoms?
A failing 2004 GM PCM can manifest in various ways, often mimicking other component failures. If you’re experiencing any of the following, your engine computer may be the culprit:
- ✔ Persistent Check Engine Light (CEL) that won’t clear.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Complete no-start or intermittent starting problems.
- ✔ Failure to communicate with diagnostic scan tools.
- ✔ Unexplained error codes related to sensors or actuators.
The Plug-and-Play Solution
Don’t waste time and money on a costly trip to the dealership. We take the complexity out of the repair process. When you order, simply provide us with your vehicle’s VIN. Our technicians will then flash this module with the most current GM calibration for your exact make and model. This ensures that all engine, transmission, and emissions parameters are set correctly from the moment you install it. This unit is a direct replacement for service numbers 12586242, 19299226, 89017738, YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, and YHTN, making it a versatile solution for a wide range of vehicles.
This module is compatible with a vast array of popular 2004 models, including the Chevrolet Silverado, SSR, Suburban, Tahoe, and Trailblazer EXT; the GMC Sierra, Yukon, and Envoy; the Cadillac Escalade; the Hummer H2; the Buick Rainier; and the Isuzu Ascender. Please verify your original part number or service ID to ensure a perfect match for your vehicle.
Frequently Asked Questions
Do I need to program this PCM?
No. This PCM comes fully programmed to your vehicle’s VIN with the latest GM software updates before it is shipped. It is ready for installation right out of the box, though a security relearn procedure may be necessary.
What is the difference between an ECM and a PCM?
The terms are often used interchangeably. An ECM (Engine Control Module) specifically manages engine functions. A PCM (Powertrain Control Module) is a more integrated unit that controls both the engine and the transmission. This part is a PCM.
Where is this module located on my 2004 truck?
Location varies by model. On full-size trucks like the Silverado, Sierra, and Yukon, it is typically found in the engine bay on the driver’s side, often under the battery tray. On mid-size SUVs like the Trailblazer and Envoy, it’s usually located next to the air filter box.
Will this part require a security relearn or CASE relearn procedure?
Yes, it’s highly likely. After installation, you will probably need to perform a security relearn (Passlock/Passkey) for the vehicle to start, and a Crankshaft Variation (CASE) relearn to prevent a P1336 trouble code. These procedures can often be done without a scan tool, and instructions are widely available online.
Why do you need my VIN?
The Vehicle Identification Number (VIN) allows us to access the specific GM calibration file for your vehicle’s engine, transmission, and options. Programming the PCM with this file ensures it works seamlessly with your vehicle, just like the original part from the factory.