2004 Sierra 1500 PCM 12586242 Engine Computer ECM

Restore Your Truck’s Performance!

Get your 2004 Sierra 1500 running smoothly with our pre-programmed PCM. This direct-fit engine computer (part #12586242) arrives ready for installation, flashed to your vehicle’s VIN. No dealer visit needed. Fix check engine lights and restore engine power. Provide your VIN at checkout and get back on the road fast!

$119.95

+11.99 USPS Priority Shipping

Availability: In stock



Guaranteed Safe Checkout

Restore Peak Performance to Your 2004 GM Truck or SUV

Is your 2004 GMC Sierra 1500, Chevrolet Silverado, or other compatible GM vehicle suffering from perplexing electrical issues? A faulty Powertrain Control Module (PCM), often called an Engine Control Module (ECM), is frequently the culprit behind problems like a persistent Check Engine Light, rough idling, poor fuel economy, or even a no-start condition. This module is the central computer for your vehicle’s engine and transmission, and when it fails, it can cause a wide range of frustrating symptoms. This replacement PCM, part 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 and a check engine light for an O2 sensor heater circuit. The owner had already replaced the sensor twice with no luck. After hooking up our scan tool and monitoring live data, we noticed the voltage commands from the PCM were erratic, not just for the O2 sensor but for several other components. Instead of continuing to chase phantom sensor issues, we identified the root cause: the PCM itself was failing. A new, correctly programmed module like this one solved all the issues in one go, saving the customer time and money on unnecessary parts.

Why Choose Our Pre-Programmed 2004 Sierra 1500 PCM?

The key to a successful PCM replacement is the programming. An unprogrammed module will not work in your vehicle. Our service eliminates the hassle and expense of a trip to the dealership. When you purchase this module, we flash it with the latest GM-certified software updates specific to your vehicle’s Vehicle Identification Number (VIN). This ensures that it communicates perfectly with your truck’s existing systems, including the engine, transmission, and anti-theft system. The result is a true plug-and-play installation process that gets you back on the road quickly.

Common Symptoms of a Failing PCM

  • ✔ Persistent Check Engine Light (CEL) illumination
  • ✔ Stalling, stumbling, or hesitation during acceleration
  • ✔ Rough or erratic engine idle
  • ✔ Noticeable decrease in fuel efficiency
  • ✔ Harsh or incorrect automatic transmission shifting
  • ✔ Engine cranks but fails to start
  • ✔ Communication errors with diagnostic scan tools
  • ✔ False sensor codes that return after replacement

Guaranteed Fitment and Compatibility

This PCM is a direct replacement for units with service numbers 12586242, 19299226, 89017738, YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, or YHTN. It is designed to fit a wide range of 2004 model year GM vehicles, including:

  • Chevrolet Avalanche, Silverado, Suburban, Tahoe, SSR, Trailblazer EXT
  • GMC Sierra, Sierra Denali, Yukon, Yukon XL, Envoy XL, Envoy XUV
  • Cadillac Escalade, Escalade ESV, Escalade EXT
  • Buick Rainier
  • Hummer H2
  • Isuzu Ascender

Please verify your original part number or service ID to ensure a perfect match. Upon purchase, simply provide us with your VIN, and we’ll handle the rest, ensuring the module you receive is precisely calibrated for your truck’s specific configuration.

Frequently Asked Questions

Do I need to do any programming after I receive this PCM?

No. This PCM arrives fully programmed to your vehicle’s VIN with the latest GM updates. It is ready for installation right out of the box. In most cases, you will not need a scan tool or a trip to the dealer. However, some vehicles may require a security relearn procedure, which is a simple process you can typically do yourself.

Where do I provide my vehicle’s VIN?

You can provide your VIN during the checkout process in the notes section, or you can send it to us in a message after your purchase. We cannot ship your order until we receive the VIN, as the programming is essential for the part to function.

Is this a plug-and-play part?

Yes, because we program it to your VIN, it is designed to be a plug-and-play solution. You will need to disconnect the battery, remove your old PCM, install the new one, and reconnect the battery. On some models, a simple security relearn procedure (often called a CASE relearn) may be necessary, which can be done without special tools.

How can I be sure this PCM will fit my vehicle?

The best way to confirm compatibility is to match the service number from your original computer to one of the numbers listed in this description (e.g., 12586242, YFKX). This part fits a wide range of 2004 GM trucks and SUVs with V8 engines. If you are unsure, please contact us with your VIN before ordering.

What is the difference between a PCM and an ECM?

The terms are often used interchangeably. ECM stands for Engine Control Module, while PCM means Powertrain Control Module. In most modern vehicles like your 2004 Sierra, the PCM controls both the engine and the transmission, making it the more accurate term. This module serves as the complete powertrain computer.

Condition

Refurbished

Year

Genuine OEM

Yes

MPN

YFKX

Interchange part number

Model

Sierra 1500

Year

2004

Brand

GM

Manufacturer Part Number

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superseded part number

12586242 19299226 89017738 YFKD, YFKF YFKH YFKJ YFKX YFXL, YFXM YFXN YFXP YHTN

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