Programmed 2003 Sierra 3500 PCM Powertrain Control Module 12576869

Restore Your Truck’s Power Today

Is your 2003 Sierra 3500 suffering from no-starts, poor mileage, or a persistent check engine light? This Powertrain Control Module (PCM) is the solution. It arrives programmed to your truck’s specific VIN with the latest GM software, eliminating the need for a costly dealership visit. Restore reliability and performance with this direct-fit part. Order now to get your workhorse back on the road fast!

$98.95

+11.99 USPS Priority Shipping

Availability: In stock



SKU: 590-06724-71 Categories: ,
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Restore Peak Performance to Your GM Heavy-Duty Truck

If your 2003 GMC Sierra 3500 is experiencing baffling issues like random stalling, no-start conditions, erratic shifting, or a persistent Check Engine Light, the culprit is often a failing Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen how a faulty PCM can cripple even the most robust trucks, turning your reliable workhorse into a source of constant frustration. This isn’t just an inconvenience; it’s lost time and money. This replacement PCM, part number 12576869, is the definitive solution to restore your truck’s brain and get you back on the road with confidence.

The PCM is the central command center for your vehicle’s engine and transmission. It processes data from dozens of sensors to manage everything from fuel injection and ignition timing to transmission shift points and emissions controls. When it fails, the symptoms can be widespread and confusing. You might chase what you think is a sensor issue, only to find the root cause lies within the module itself. This is where our solution provides real value. We eliminate the guesswork and the costly trip to the dealership for programming. Each 2003 Sierra 3500 PCM we ship is meticulously flashed with the latest official GM software updates, tailored specifically to your truck’s Vehicle Identification Number (VIN). This ensures seamless communication between all vehicle modules and optimal performance from day one.

From the Diagnostic Bay: The 8.1L That Wouldn’t Start

A customer brought in his ’03 Silverado 2500 with the 8.1L big block—a truck nearly identical under the hood to your Sierra 3500. The complaint was an intermittent no-start. It would crank but never fire. Sometimes it would start after sitting for an hour. He had already replaced the crank sensor and fuel pump. My scan tool couldn’t communicate with the PCM, a major red flag. After checking powers and grounds to the module, which were all good, I knew the PCM was the issue. These P59 controllers are generally robust, but heat cycles and vibrations under the battery tray eventually take their toll. A replacement, VIN-programmed module like this one had him back on the job site the next day. Don’t waste time and money on the wrong parts; a communication failure with the PCM almost always points to the module itself.

Is Your Truck Showing These PCM Failure Signs?

A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your module needs replacement. Look out for these common symptoms and associated diagnostic trouble codes (DTCs):

  • ✔ No-start or hard-starting conditions, especially when warm.
  • ✔ Unexplained stalling or engine stumbling while driving.
  • ✔ Drastically reduced fuel economy.
  • ✔ Harsh or erratic automatic transmission shifting.
  • ✔ Check Engine Light is on with internal module codes like P0601, P0602, or P0606.
  • ✔ Loss of communication with the scan tool (U-codes).
  • ✔ Engine performance issues that aren’t resolved by replacing sensors.

A Straightforward Guide to PCM Installation

Installing your new 2003 Sierra 3500 PCM is a manageable job for a DIYer with basic tools. Because we program it to your VIN beforehand, you skip the most complicated step. Follow this general process for a successful installation:

  1. Safety First: Always disconnect the negative terminal from your truck’s battery to prevent any electrical shorts.
  2. Locate the PCM: On most 2003 GM trucks like the Sierra, the PCM is located on the driver’s side of the engine bay, typically under or near the battery tray.
  3. Disconnect the Connectors: Carefully unclip and remove the electrical harness connectors from the old PCM. These connectors have locking tabs; be gentle to avoid breaking them.
  4. Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need to reuse it.
  5. Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten it.
  6. Reconnect Everything: Plug the harness connectors firmly into the new PCM until they click into place. Reconnect the negative battery terminal.
  7. Perform Security Relearn: You will likely need to perform a simple security relearn procedure, which can typically be done with just the ignition key. This allows the vehicle’s anti-theft system to recognize the new PCM. Instructions are readily available online for your specific model.
  8. CASE Relearn (Recommended): For optimal performance and to prevent a P1336 trouble code, a Crankshaft Variation (CASE) relearn is recommended. Most professional-grade scan tools can perform this procedure in a few minutes.

Verified Compatibility for Your GM Vehicle

This module is a direct-fit replacement for a wide range of General Motors trucks and vans. It is compatible with multiple service numbers, including 12576869, 12581565, 12570557, and more. Please verify your vehicle is on the list below. Providing your VIN at checkout is essential for us to ensure perfect programming and compatibility.

Fits Models Including:

  • 2003 Sierra 1500/2500/3500 Pickup (4.3L, 8.1L Gasoline)
  • 2003 Silverado 2500/3500 Pickup (8.1L Gasoline)
  • 2003 Avalanche 2500 (8.1L)
  • 2003 Suburban 2500 (8.1L)
  • 2003 Yukon XL 2500 (8.1L)
  • 2003 Express & Savana Vans (1500, 2500, 3500)
  • 2003 Astro & Safari Vans
  • 2003 S10/Sonoma & Blazer/Jimmy (4.3L)
  • 2004 Corvette & CTS (with matching ID 12581565)

Order your pre-programmed 2003 Sierra 3500 PCM today and restore the reliability and power you depend on.

Frequently Asked Questions

Do I need to send my old PCM back (core charge)?

No core charge is required for this module. You can keep your old part, which saves you the time and hassle of return shipping.

Is this part difficult to install myself?

Installation is straightforward for those with basic mechanical skills. The main tasks are disconnecting the battery, swapping the module, and reconnecting it. Since we program it for you, no special computer equipment is needed for the initial setup.

What is the VIN and why do you need it?

The VIN (Vehicle Identification Number) is your truck’s unique 17-digit serial number. We require it to load the exact, correct GM factory software for your specific engine, transmission, and options. This ensures your truck runs exactly as it should without any compatibility issues.

Will I need to do anything after installation?

Yes. After installing the PCM, you will need to perform a simple security relearn procedure so the truck’s anti-theft system syncs with the new module. A CASE (Crankshaft Variation) relearn is also highly recommended with a scan tool to ensure smooth engine operation and prevent certain trouble codes.

What if my part number is slightly different?

This module replaces many different service numbers. Please check the compatibility list provided. As long as your vehicle, year, and engine are listed, and you provide your VIN, we will ensure the programming is a perfect match for your application.

Conditions & Options

Programmed to your VIN GM: 12576106

Year
Genuine OEM

Yes

MPN

12576869

Interchange part number

Condition

Refurbished

Model

Sierra 3500 Pickup

Year

2003

Brand

GM

Manufacturer Part Number

, , , , , , , , ,

GTIN

Does not apply

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