Restore Peak Performance to Your GM Truck or Van
Is your truck suffering from baffling electrical gremlins, a persistent Check Engine Light, or unpredictable performance? As the brain of your vehicle’s engine and transmission, a failing Powertrain Control Module (PCM) can cause a host of frustrating issues. This is a direct-fit, professionally programmed PCM for your 2003 Chevrolet Silverado 2500 and other compatible GM vehicles. We take the guesswork and dealership hassle out of the equation. By providing your Vehicle Identification Number (VIN) at checkout, you receive a module that is flashed with the latest official GM software specific to your vehicle, ensuring a seamless and effective repair.
A Technician’s Notebook: The Intermittent Stall
I once had a 2003 Sierra 2500 with the 8.1L in my bay that was driving the owner crazy. It would randomly stall at stoplights, but only when warm. No consistent codes, just a history of random communication faults. We checked fuel pressure, sensors, and wiring harnesses for days. On a hunch, I monitored the PCM’s internal temperature data while running a heat gun over the module itself. Sure enough, as the PCM case got hot, the data stream would drop out, causing the stall. The internal processor was failing under thermal stress—a classic sign of PCM failure. Replacing it with a properly programmed unit like this one solved the problem instantly. It’s not always the most obvious part, but a failing PCM can mimic dozens of other issues.
Is Your Vehicle Showing These Signs of PCM Failure?
A faulty engine computer can manifest in numerous ways. If you’re experiencing any of the following, a failing PCM could be the culprit. In my 20+ years of diagnostics, these are the most common symptoms I’ve traced back to the module itself.
- ✔ Unexplained Check Engine Light (CEL) illumination
- ✔ Stalling, stumbling, or rough idling
- ✔ Drastic decrease in fuel economy
- ✔ The engine won’t start, even with a good battery and starter
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Diagnostic Trouble Codes (DTCs) stored, especially P0601, P0606, or U-series communication codes
- ✔ Failure to pass an emissions inspection
Your Straightforward Installation Guide
Installing your new PCM is a manageable job for a DIYer with basic tools. For the 2003 Silverado 2500, the PCM is typically located on the driver’s side, under the battery tray. Always consult a repair manual for your specific vehicle’s location.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Access the Module: You may need to remove the battery and the battery tray to gain clear access to the old PCM.
- Disconnect Connectors: Carefully unclip the wiring harness connectors from the old module. These connectors have locking tabs; be gentle to avoid breaking them.
- Remove Old PCM: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install New PCM: Mount the new, pre-programmed PCM in the same location and securely fasten it.
- Reconnect Everything: Firmly plug the wiring harness connectors into the new module until they click. Reinstall the battery tray and battery, then reconnect the negative battery terminal.
- Perform Security Relearn: Most GM vehicles of this era require a security relearn procedure to sync the new PCM with your vehicle’s anti-theft system. This can typically be done without special tools by cycling the key. A common method is: Turn the key to ‘ON’ for 10 minutes, ‘OFF’ for 10 seconds, and repeat this cycle three times. Your vehicle should then start.
Verified Fitment for Your GM Vehicle
This module is a direct replacement for part number 89017733 and several other service numbers. It is guaranteed to fit the following vehicles. Please ensure your vehicle and options match the list below.
- ✔ 2003 Avalanche 2500: Electronic Control Module; (LH front under battery)
- ✔ 2003-2004 Cadillac CTS & Corvette: See specific fitment notes in description
- ✔ 2003 Chevrolet Express / GMC Savana Vans (1500, 2500, 3500): Electronic Control Module; (LH rear engine compartment)
- ✔ 2003 Chevrolet Silverado / GMC Sierra Pickup (1500, 2500, 3500): Powertrain Control Module; (LH front under battery), specific engines noted
- ✔ 2003 Chevrolet S10 / GMC Sonoma / Blazer / Jimmy: Electronic Control Module; (RH front engine compartment)
- ✔ 2003 Chevrolet Astro / GMC Safari: Electronic Control Module; (LH front by battery)
- ✔ 2003 Suburban 2500 / Yukon XL 2500: Electronic Control Module; (LH front under battery), 8.1L
Frequently Asked Questions
How do I provide my VIN for programming?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s 17-digit VIN. We cannot ship the module until we receive this information, as the programming is essential for it to function in your truck.
Is any additional programming required after installation?
The core engine and transmission software will be fully loaded. However, you will need to perform the vehicle’s security relearn procedure, which pairs the module to your keys. You may also need a CASE (Crankshaft Angle Sensor Error) relearn, which requires a capable scan tool, to clear a potential P1336 code.
Why is this better than a used part from a salvage yard?
A used module from a junkyard will be programmed for the donor vehicle and will not work in your truck without being completely wiped and reprogrammed by a dealer or specialized shop, adding significant cost and hassle. Our module arrives ready to install with the latest GM software for your specific VIN.
What if I have the wrong part number?
This module replaces a wide range of original service numbers, including 12581565, 12570557, 12576106, and 89017733 among others. As long as your vehicle is on the compatibility list, this module will function correctly once programmed to your VIN.